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CHNG 5 CC PHNG PHP, THIT B V IU KHIN QU TRNH LN MEN
Trong t nhin xy ra mun vn cc qu trnh ln men do hot ng sng ca vi
sinh vt. C th ni rng bt c mt hp cht no c trong t nhin vi sinh vt
cng c th tng hp c. Do vy ln men l mun hnh mun v, nhng tt c cc qu
trnh ny d l trong t nhin, trong phng th nghim hay trong sn xut cng
nghip u c mt nguyn l ging nhau. Nghin cu mt qu trnh ln men thc cht
l nghin cu cc c im sinh l ho sinh v hot ng sng ca mt chng vi sinh
vt, cc c im nui cy ca n vi cc thng s nh thnh phn dinh dng, cc yu t
nh hnh v hot ng ca ton th qu trnh ny trong sn xut cng nghip. 5.1.
Cc phng php ln men Tu thuc c im sinh l ca vi sinh vt nui cy i vi
oxy, ta coi qu trnh l hiu kh hay k kh khng bt buc. i vi ln men k kh
thc hin theo phng php nui cy chm, ngha l vi sinh vt nui cy su tronh
mi trng, thnh thong khuy tng s trao i gia t bo vi sinh vt vi mi
trng trong sut qu trnh khng sc kh. Vi qu trnh ln men k kh khng bt
buc, nh trong ln men ru cc ging men khi c oxy th ng sang sinh trng,
tng sinh khi, khi thiu oxy th ng sang hng tch t etanol. V vy ln men
ru thi k u thng c cp khng kh ging nm men pht trin tt, sau ngng sc
kh ln men ru. Ln men hiu kh c thc hin nh hai phng php c bn: nui cy
b mt v nui cy b su. 5.2. Ln men b su trong mi trng lng
Ln men chm l phng php c ph bin rng nht trong quy trnh ln men cng
nghip, v c th kim sot c ton b cc khu trong qu trnh mt cch d dng. So
vi phng php ln men b mt, th ln men chm c nhiu u im l: t chon b mt
(khng mt nhiu din tch), d c gii ha v t ng ha trong qu trnh theo di.
Tuy nhin phng php ln men chm i hi u t nhiu kinh ph cho trang thit
b. Ngoi ra, nu mt m ln men, v mt l do no b x l th khng th x l cc b
c, a phn phi hy b c qu trnh ln men, gy tn km ln. Ph liu ca qu trnh
ln men thi ra phi km theo cng ngh x l chng nhim mi trng.
Phng php ny dng cho c vi sinh vt k kh v hiu kh. i vi nui vi sinh
vt k kh trong qu trnh nui khng cn sc kh ch thnh thong khuy trn cn
vi vi sinh
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vt hiu kh th phi sc kh lin tc. y l phng php hin i c dng trong
khong na cui th k XX v cho kt qu rt to ln i vi cng ngh vi sinh.
Nui cy chm hay nui cy b su dng mi trng dch th. Chng vi sinh vt
cy vo mi trng c phn tn khp mi im v chung quanh b mt t bo c tip xc
vi dch dinh dng. c im ny i hi trong sut qu trnh nui cy phi khuy v
cung cp xy bng cch sc kh lin tc. Ngy nay phng php nui cy chm c dng
ph bin trong cng ngh vi sinh sn xut men bnh m, protein n bo, cc ch
phm vi sinh lm phn bn, thuc tr su, cc enzyme, cc acid amin,
vitamin, cc cht khng sinh, cc cht kch thch sinh hc v.v...
Phng php nui cy chm c mt s u im: - Tn t mt bng trong xy dng v lp
t dy chuyn. - Chi ph in nng, nhn lc v cc khon ph cho mt n v sn phm
thp. - D t chc c x nghip c sn lng ln. - Cc thit b ln men chm d c kh
ho, t ng ho . Song phng php chm cng c mt s nhc im sau: - i hi trang
b k thut cao, d b nhim trng ton b. V vy, nhng thit b ln
men chm cn phi ch to c bit cn thn, chu p lc cao, i hi kn v lm
vic vi iu kin v trng tuyt i (trong nui cy b mt c th loi b phn nhim
trng, cc phn khc vn cn dng c).
- Trong ln men chm cn phi khuy v sc kh lin tc v vi sinh vt ch s
dng c xy ho tan trong mi trng. Kh c nn qua mt h thng lc sch tp
trng, h thng ny tng i phc tp v d gy nhim cho mi trng nui cy 5.2.1.
Ln men gin on Trong phng php nui khng lin tc (batch - culture) hay
cn gi l nui gin on, thng thng vi sinh vt sinh trng n chng no mt
thnh phn ch yu ca mi trng dinh dng b gii hn. Khi culture chuyn t
pha lu tha sang pha cn bng. Sinh trng gn lin vi s thay i ko di ca
iu kin nui, s gim cht dinh dng v s tng khi lng t bo. Trong qu trnh
trng thi sinh l ca t bo cng thay i. Thng thng vic to thnh sn phm
mong mun lin quan vi mt trng thi sinh l nht nh trong pha sinh trng.
Khng th duy tr c trng thi ny trong mt thi gian di. Phng php nui gin
on c s dng trc ht cho s ln men v trng,v cch nui ny l d dng v mt k
thut.
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Sinh trng l biu th s tng trng cc thnh phn ca t bo. i vi cc vi
sinh vt c hnh thc sinh sn bng ny chi hay phn i th sinh trng dn ti s
gia tng s lng t bo. T bo tng trng n mt mc nht nh th s phn ct thnh
hai t bo th h con c kch thc hu nh bng nhau. i vi cc vi sinh vt a
nhn th s phn cch nhn khng ng hnh vi s phn ct t bo - s sinh trng lm
tng kch thc t bo m khng lm tng s lng t bo. V vi sinh vt rt nh b cho
nn l i tng rt khng thun tin nghin cu v sinh trng v pht trin. Chnh v
vy m khi nghin cu v sinh trng, ngi ta thng xt n s bin i v s lng ca
c qun th vi sinh vt.
NG CONG SINH TRNG
S sinh trng qun th vi sinh vt c nghin cu bng cch phn tch ng cong
sinh trng trong mt mi trng nui cy vi sinh vt theo phng php nui cy
theo m (batch culture) hoc trong mt h thng kn. C ngha l vi sinh vt
c nui cy trong mt thit b kn, trong qu trnh nui cy khng thay i mi
trng v thi gian nui cy cng ko di th nng cht dinh dng cng gim st, cc
cht ph thi ca trao i cht cng tng ln. Nu ly thi gian nui cy l trc
honh v ly s logarit ca s lng t bo sng lm trc tung s c th v c ng
cong sinh trng ca cc vi sinh vt sinh sn bng cch phn i. ng cong ny c
4 giai on (phases) khc nhau.
Hnh 14.1: ng cong sinh trng trong h thng kn (Theo sch ca
Prescott, Harley v Klein)
Giai on Tim pht (Lag phase)
Khi cy vi sinh vt vo mt mi trng mi s lng thng khng tng ln ngay,
l giai on Tim pht hay pha Lag. Trong giai on ny t bo cha phn ct
nhng th tch v khi lng tng ln r rt do c s tng cc thnh phn mi ca t
bo. Nguyn nhn l do t bo trng thi gi, thiu ht ATP, cc cofactor cn
thit v ribosome. Thnh phn mi trng mi khng ging mi trng c cho nn t
bo cn mt thi gian nht nh tng hp cc enzyme mi nhm s dng c cc cht
dinh dng
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mi. Cc t bo cng c th b thng tn v cn mt thi gian hi phc. Bt k v
nguyn nhn g th kt qu vn l t bo phi t trang b li cc thnh phn ca mnh,
ti to ADN v bt u tng khi lng. Giai on tim pht di hay ngn lin quan n
bn thn tng loi vi sinh vt v tnh cht ca mi trng. Nu tnh cht ha hc ca
mi trng mi sai khc nhiu vi mi trng c th giai on tim pht s ko di.
Ngc li, nu cy t giai on logarit vo mt mi trng c thnh phn tng t th
giai on tim pht s rt ngn li. Nu cy vi sinh vt t giai on tim pht hay
t giai on t vong th giai on tim pht s ko di.
Giai on logarit (Log Phase) hay Pha Ch s (Exponential Phase)
Trong giai on ny vi sinh vt sinh trng v phn ct vi nhp ti a so vi
bn tnh di truyn ca chng nu gp mi trng v iu kin nui cy thch hp. Nhp
sinh trng ca chng l khng thay i trong sut giai on ny, cc t bo phn i
mt cch u n. Do cc t bo sinh ra ch khc nhau rt t cho nn ng cong sinh
trng l mt ng trn nhn ch khng gp khc (hnh 14.1). Qun th t bo trong
giai on ny c trng thi ha hc v sinh l hc c bn l nh nhau cho nn vic
nui cy giai on ny thng c s dng nghin cu sinh ha hc v sinh l hc vi
sinh vt.
Sinh trng logarit l sinh trng ng u, tc l cc thnh phn t bo c tng
hp vi tc tng i n nh. Nu cn bng dinh dng hay cc iu kin mi trng thay
i s dn n s sinh trng khng ng u. S sinh trng khi nhp tng hp cc thnh
phn ca t bo tng i bin ha s bin i theo cho n khi t ti mt s cn bng
mi. Phn ng ny rt d quan st thy khi lm thc nghim chuyn t bo t mt mi
trng ngho dinh dng sang mt mi trng giu hn. T bo trc ht phi to nn cc
ribosome mi c th nng cao nng lc tng hp protein, sau l s tng cng tng
hp protein v ADN. Cui cng tt yu dn n tc pht trin nhanh chng.
Lc chuyn qun th t bo t mt mi trng giu dinh dng ti mt mi trng
ngho th cng c kt qu v s sinh trng khng ng u nh vy. Vi sinh vt trc c
th thu c t mi trng nhiu thnh phn ca t bo nhng khi chuyn sang mi
trng ngho chng cn c thi gian to ra cc enzyme cn thit sinh tng hp cc
thnh phn khng c sn trong mi trng. Sau t bo mi c th phn ct, ADN mi c
th ti to, nhng vic tng hp protein v ARN l chm cho nn t bo nh li v t
chc li s trao i cht ca chng cho n khi chng c th sinh trng tip. Sau
s sinh trng cn bng s c hi phc v tr v li giai on logarit.
Cc th nghim trn y cho thy s sinh trng ca vi sinh vt c kim sot mt
cch chnh xc, phi hp v phn ng nhanh chng vi nhng s bin i ca mi
trng.
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33
Khi s sinh trng ca vi sinh vt b hn ch bi nng thp ca cc cht dinh
dng cn thit th sn lng t bo cui cng s tng ln cng vi s tng ln ca cc
cht dinh dng b hn ch (hnh 14.2a). y chnh l c s s dng vi sinh vt
trong vic nh lng vitamin v cc nhn t sinh trng khc. Tc sinh trng cng
tng ln cng vi s tng nng cc cht dinh dng (hnh 14.2b). Hnh dng ca ng
cong hu nh phn nh tc hp thu cht dinh dng nh s chuyn vn protein ca
vi sinh vt. Lc nng cht dinh dng cao th h thng vn chuyn s bo ha v tc
sinh trng khng tng ln cng vi s tng ln ca nng cht dinh dng.
Hnh 14.2: Nng cht dinh dng v sinh trng
(a )- nh hng ca s hn ch cht dinh dng i vi sn lng chung ca vi
sinh vt. Lc nng cao th sn lng chung s t ti n nh.
(b)- nh hng ca s hn ch cht dinh dng ti tc sinh trng.
Giai on n nh (Stationary Phase) hay Pha Cn bng
Qua giai on Logarit s sinh trng ca qun th cui cng s dng li, ng
cong sinh trng i ngang (hnh 14.1). Nng vi khun trong giai on n nh
thng vo khong 109/ml. Vi cc vi sinh vt khc thng khng t c n nng ny.
Vi ng vt nguyn sinh v vi to thng ch t n nng 10 6/ml. ng nhin, s lng
t bo cui cng quyt nh bi nh hng chung ca iu kin dinh ng, chng loi vi
sinh vt v cc nhn t khc. Trong giai on ny s lng t bo sng l khng thay
i, c th do s lng t bo mi sinh ra cn bng vi s lng t bo cht i, hoc l
t bo ngng phn ct m vn gi nguyn hot tnh trao i cht.
C nhiu nguyn nhn lm cho qun th vi sinh vt chuyn sang giai on n
nh. Trong nguyn nhn ch yu l s hn ch ca cht dinh dng. Nu mt cht dinh
dng thit yu b thiu ht nghim trng th s sinh trng s chm li. Vi sinh
vt hiu kh thng b hn ch bi nng oxygen. Oxygen thng ha tan t trong
nc,
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34
O2 trong ni b mi trng rt nhanh chng b tiu th ht, ch c cc vi sinh
vt sinh trng b mt mi trng mi c nng O2 sinh trng. V vy khi nui cy vi
sinh vt phi s dng ti my lc hay cc bin php thng kh khc. Qun th vi
sinh vt cng c th b nh ch sinh trng khi gp s tch ly ca cc sn phm
trao i cht c hi. Mt s vi sinh vt k kh (nh Streptococcus) c th ln
men ng lm sn sinh mt lng ln acid lactic hay cc acid hu c khc, lm
acid ha mi trng v c ch s sinh trng ca vi sinh vt. ng thi s tiu hao
ht ng cng lm cho t bo i vo giai on n nh. Sau na l, mt s chng c cho
thy khi s lng vi sinh vt t n mt gii hn nht nh th s sinh trng c th b
nh ch. S sinh trng ca vi sinh vt chuyn sang giai on n nh c th do kt
qu chung ca rt nhiu nhn t khc nhau
Nh chng ta. thy vi khun khi nui cy theo m s chuyn sang giai on n
nh khi thiu thc n. Trong t nhin, do nhiu mi trng c nng ch dinh dng
rt thp nn vi sinh vt thng chuyn sang giai on n nh. i vi vi khun vic
chuyn sang giai on n nh c th l mt loi thch ng tt. Nhiu loi vi khun
khng c s bin ha r rt v hnh thi (nh hnh thnh bo t ni sinh-endospore)
nhng chng c th thu nh kch thc li, thng do cht nguyn sinh co li v
nhn gi (nucleoid) m c li. Mt bin i quan trng hn l, khi thiu thc n
vi khun s sinh ra mt loi protein i (starvation proteins) lm cho t
bo khng nhiu hn vi cc thng tn bng nhiu con ng khc nhau. Chng lm tng
cc lin kt peptidoglycan v s bn vng ca thnh t bo. Chng hn Dps
(DNA-binding protein from starved cells), mt loi protein kt hp vi
ADN ly t cc t bo i, c th bo v cho ADN. Phn t Chaperones cn tr s bin
tnh ca protein v hi phc li c cc protein b tn thng. V nhng vic v
nhiu c ch khc m cc t bo i c th kh b cht i v khng c vi tnh trng b i,
vi s bin ha ca nhit , s tn thng v xy ha v s thm thu, cng nh tng sc
khng vi cc ha cht c hi (nh chlorine chng hn). Nhng ci bin ny rt c
hiu qu v lm cho mt s vi khun c th sng li sau vi nm b i. R rng vic
hiu r nhng vn ny s c tm quan trng thc tin to ln i vi y hc v vi sinh
vt hc cng nghip. Chng cn c th chng minh vi khun thng hn (Salmonella
typhimurium) v nhiu vi khun gy bnh khc c th c kh nng gy bnh mnh hn
khi b i.
Giai on t vong (Death Phase)
Vic tiu hao cht dinh dng v vic tch ly cc cht thi c hi s lm tn
tht n mi trng sng ca vi sinh vt, lm cho s lng t bo sng gim xung. l
c im ca giai on t vong. Ging nh giai on logarit, s t vong ca qun th
vi sinh vt cng c tnh logarit (t l t bo cht trong mi gi l khng i).
Tng s t bo sng v t bo cht khng thay i v cc t bo cht cha b phn hy.
Mun xc nh s lng t bo sng phi pha long ra ri cy ln thch a v a vo iu
kin thch hp xc nh s khun lc xut hin. Mc du phn ln vi sinh vt t vong
theo phng thc logarit nhng sau khi s lng t bo t nhin gim xung th tc
cht
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35
ca t bo chm li. l do mt s c th sng li nh c tnh khng c bit mnh. V
iu ny v nhng nguyn nhn khc lm cho ng cong ca giai on t vong c th kh
phc tp.
Tnh ton v qu trnh sinh trng
Khng t cc nh vi sinh vt hc tnh ton v tc sinh trng ca vi sinh vt
trong giai on logarit. Tnh ton nhp sinh trng s lm c s cho cc nghin
cu v sinh l hc, sinh thi hc vi sinh vt, v cn gii quyt mt s vn ng
dng trong sn xut cng nghip.
Trong giai on logarit mi c th vi sinh vt tin hnh phn ct trong mt
thi gian hng nh. S lng t bo tng theo phng thc 2n. Thi gian gia hai
ln phn chia lin tip hay thi gian cn cho s tng i s t bo c gi l thi
gian th h (generation time hay doubling time). V d a mt t bo vo mi
trng nui cy, c 20 pht phn ct mt ln th sau 20 pht c 2 t bo, sau 40
pht c 4 t bo v tip tc nh vy (bng 14.1)
Bng 14.1: Mt v d v sinh trng theo logarit
Thi gian* S ln phn ct 2n S lng (N0 x 2n) lg10 Nt 0 0 20=1 1
0,000
20 1 21=2 2 0,301 40 2 22=4 4 0,602 60 3 23=8 8 0,903 80 4 24=16
16 1,204 100 5 25=32 32 1,505 120 6 26=64 64 1,806
*Thi gian th h l 20 pht, gi thit l nui cy t 1 t bo
S lng logarit t bo l 2n, n l s th h. C th biu th cc s liu trong
bng 14.1 bng cng thc sau y:
Trong : N0 l s lng t bo ban u; Nt l s lng t bo thi gian t; n l s
th h.
T cng thc trn c th bin i nh sau v s th h n c tnh bng logarit thp
phn:
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36
Khi nui cy phn m (batch culture) tc sinh trng trong giai on
logarit c th biu th bng hng s tc sinh trng bnh qun k (mean growth
rate constant k). l s th h sinh ra trong n v thi gian, thng biu th
bng s th h trong 1 gi:
Thi gian cn thit tng gp i tng s t bo l thi gian th h bnh qun
(mean generation time) hay thi gian tn gp i bnh qun (mean doubling
time) v c biu th bng g. Nu t=g th N t= 2N0. Thay vo cng thc trn ta
c:
Thi gian th h bnh qun l o s ca hng s tc sinh trng bnh qun:
Thi gian th h bnh qun g c th cn c trc tip vo th bn logarit
(semilogarithmic plot) v hng s tc sinh trng tnh ra (hnh 14.4). V d
,s lng vi khun ti gi th 10 l t 103 tng ln n 109 th :
(th h/h)
gi/th h hay 30 pht/th h
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37
Hnh 14.3: Sinh trng th h ca vi sinh vt (biu th 6 th h)
(Theo sch ca Prescott,Harley v Klein).
Hnh 14.4; Xc nh thi gian th h.
Thi gian th h c th xc nh bng ng cong sinh trng ca vi sinh
vt.
Ly thi gian l trc honh v ly s lng t bo lm trc tung. Thi gian
tng gp i s lng ca qun th (thi gian th h) c th c trc tip trn
th
Thi gian th h thay i ty theo chng loi vi sinh vt, iu kin nui cy.
Mt s vi khun thi gian th h khng qu 10 pht (0,17h) trong khi mt s vi
sinh vt nhn thc (eucaryotic) li di ti vi ngy (Bng 14.2). Thi gian
th h trong t nhin thng l di hn so vi khi nui cy.
Bng 14.2: Thi gian th h ca mt s loi vi sinh vt
Vi sinh vt Nhit (0C) Thi gian th h (gi) Vi khun v Vi khun
lam
Beneckea natriegens 37 0,16
Escherichia coli 40 0,35
Bacillus subtilis 40 0,43
Staphylococcus aureus 37 0,47
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Pseudomonas aeruginossa 37 0,58
Clostridium botulinum 37 0,58
Rhodospirillum rubrum 25 4,6-5,3
Anabaena cylindrica 25 10,6
Mycobacterium tuberculosis 37 Khong 12
Treponema pallidum 37 33
To
Scenedesmus quadricauda 25 5,9
Chlorella pyrenoidosa 25 7,75
Asterionella formosa 20 9,6
Euglena gracilis 25 10,9
Ceratium tripos 20 82,8
ng vt nguyn sinh
Tetrahymena geleii 24 2,2-4,2
Leishmania donovani 26 10-12
Paramecium caudatum 26 10,4
Acanthamoeba castellanii 30 11-12
Giardia lamblia 37 18
Nm
Saccharomyces cerevisiae 30 2
Monilinia fructicola 25 30
XC NH S SINH TRNG CA VI SINH VT
C nhiu cch thng qua vic xc nh s bin i s lng v cht lng vi sinh vt
hiu c s sinh trng ca vi sinh vt, bit c tc sinh trng v thi gian th
h. Di y s gii thiu cc phng php thng dng nht cng cc u, khuyt im ca
cc phng php ny. Khng c phng php no l tt nht, la chn phng php no cn
ph thuc vo tng trng hp c th.
Xc nh s lng t bo
Phng php n gin nht xc nh s lng t bo l m trc tip di knh hin vi.
Dng cc phng m m va nhanh chng, d dng, li r tin nht, li c th
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39
quan st thy kch c v hnh dng t bo. Thng dng phng m
Petroff-Hausser m t bo ng vt nguyn sinh. Dng phng m hng cu c th m c
cc t bo nhn nguyn thy cng nh t bo nhn tht. Vi t bo nhn nguyn thy cn
nhum mu hoc l dng knh hin vi tng phn pha hay knh hin vi hunh quang
(phase-constrast or fluoresence microscope) d quan st hn. Phng m c
cu trc c mt su nht nh li c chia ra thnh cc nh (hnh 14.5). Khi m s
lng ta a dch pha long vo phng m, y l knh (lamelle/ cover glass) ln
trn, sau tin hnh m s lng di knh hin vi. Khuyt im ca phng php ny l
khng xc nh c vi cc mu c s lng vi khun qu nh, chnh xc cng khng cao v
khng phn bit c gia t bo sng v t bo cht.
Hnh 14.5: Phng m Petroff-Hauser:
(a)- Mt nhn nghing ca phng m- Phng m cha dch huyn ph vi khun l
khong khng gian bn di l knh; (b)- Gia phin knh c phng m vi cc nh;
(c) phng i khong x 400-500 tin hnh m s lng vi khun trong cc nh. Ly
s lng bnh qun tnh ra mt vi khun trong mu vt. Trong phm vi 1mm2 c
225 nh , do s lng vi khun trn 1mm2 l (s vi khun/mm) x 25; v phng m
c chiu dy l 0,02mm do nng vi khun trong phng m l: (s vi khun)/m2 x
25 (tng s nh) x 50= s vi khun/mm 3.
V 1 cm3=1 mm3 x 103cho nn gi th s lng vi khun bnh qun trong mi
nh l 28 th trong 1 cm3 c nng vi khun l 28 x 25 x 50 x103= 3,5 x
107vi khun. Nhn vi pha long ban u (nu c) s bit c nng vi khun trong
mu kim tra.
Vi ng vt nguyn sinh, vi to v nm men c th dng my m in t nh loi my
Coulter Counter xc nh s lng. Nguyn l l hai bn mi l nh c in cc v ni
in. Khi t bo trong dch huyn ph i qua l nh th c mi t bo i qua th
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40
in tr li tng ln (hoc tnh dn in gim xung) v sinh ra mt tn hiu in,
my m s t ng ghi s. Kt qu xc nh ca loi my ny kh chnh xc, c th ng dng
rng ri xc nh s lng hng cu v bch cu, nhng phng php ny khng thch hp
xc nh s lng vi khun v d b can thip bi cc ht nh v cc vt cht dng si
trong mu vt.
C hai phng php ni trn u khng phn bit c t bo sng v t bo cht. xc
nh s lng t bo sng ngi ta thng dng phng php cy dch pha long ln b mt
mi trng thch a. Sau khi nui cy mi vi khun s to thnh 1 khun lc. V d
pha long 1 x 10-6 m c 150 khun lc th c ngha l mt vi khun trong mu l
1,5 x 108.
Dng dng c m khun lc cng thm thun tin. Phng php ny cho bit s lng
cc t bo sng ca vi sinh vt. Phng php ny n gin, nhy cm v thch hp ng
dng rng ri xc nh s lng vi sinh vt sng khi phn tch cc mu thc phm,
nc, t...Tuy nhin kt qu cng chu nh hng ca mt s nhn t. Nu vi khun dnh
thnh khi khng tch ri nhau ra th kt qu thu c l thp hn thc t., v mi
khun lc khng pht trin t mt t bo ring r. V vy kt qu thu c t phng php
ny c coi l s n v hnh thnh khun lc (CFU-colony forming unit). CFU
khng hon ton ph hp vi s t bo sng trong mu vt. Trong qu trnh s dng
phng php ny nn s dng pha long no cho s khun lc xut hin trn a ch nm
trong phm vi khong 30-300 m thi. ng nhin mi trng dinh dng khng th p
ng chung cho mi loi vi sinh vt, do kt qu thu c bao gi cng thp hn
thc t. Khi trn thch vi dch pha long th thch ngui khng lm cht vi
khun hay lm thng tn vi mt s loi mn cm vi nhit . Vic cy cy dch pha
long trn b mt ri dn u bng que gt thy tinh thng cho kt qu cao hn v s
lng vi sinh vt so vi phng php trn vi mi trng thch cha ng.
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Hnh 14.6: Tch khun lc v phng php kim tra s lng vi sinh vt thng
qua m khun lc mc trn mi trng thch a.
(a) (b)- Cch ria cy tch khun lc ring r (khng dng m s lng)
(c)(d)- Cch pha long ri trn vi mi trng thch cha ng
(e)(f)- Cch dn dch pha long bng que gt trn mt thch (cho s lng
khun lc nhiu hn).Theo sch ca K.P.Talaro,2005.
xc nh s lng vi sinh vt cn c th nui cy giy lc lc dch pha long mu
vt. Phng php ny gi l phng php mng lc (membrane filter). Dng mt thit
b lc c bit t va mt giy lc hnh trn c cc l nh hn kch thc vi khun v cc
vi sinh vt khc. Sau khi lc t giy lc ln mi trng thch thch hp hoc thm
t mng lc bng dch mi trng thch hp ri nui cy 24 gi. m s khun lc mc
trn giy lc tnh ra mt vi khun sng c mt trong mu vt (hnh 14.7)
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Hnh 14.7: Phng php lc mng xc nh s lng vi sinh vt
Phng php ny thch hp s dng phn tch vi sinh vt trong nc. C th dng
cc mi trng khc nhau thch hp vi cc nhm vi sinh vt khc nhau (hnh
14.8)
Hnh 14.8: Cc loi khun lc mc trn mng lc. Theo sch ca
Prescott,Harley v Klein (2005)
(a)- Tng s vi khun mc trn mi trng tiu chun, Dng ch th mu nhum
khun lc cho d im;
(b)- Dng mi trng thch hp kim tra nhm vi khun coliform c ngun gc
t phn (khun lc bt mu xanh);
(c)- Dng mi trng thch m-Endo xc nh vi khun E.coli v cc Coliform
khc- khun lc c mu lc;
(d)- Nm si v nm men mc trn mi trng Thch - Mch nha.
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Phng php mng lc cn dng m trc tip vi khun. Dch mu vt c lc qua mt
mng polycarbonate mu en. Vi khun trn mng lc c nhum mu hunh quang
bng thuc nhum acridine da cam hoc DAPI (diamidino-2-phenylindole).
Quan st di knh hin vi hunh quang c th thy cc t bo vi sinh vt hin ln
mu da cam hay mu lc trn mt nn en. Hin c nhng kit thng mi cho php
phn bit t bo sng v t bo cht khi kim tra.
Xc nh khi lng t bo
S sinh trng ca vi sinh vt khng ch biu hin s lng t bo m cn c s
tng trng ca tng khi lng t bo. Phng php trc tip nht l xc nh trng lng
kh ca t bo. Trc ht cn ly tm thu nhn sinh khi t bo. Sau ra t bo ri
lm kh trong l sy ri cn trng lng kh. Phng php ny thch hp xc nh s
sinh trng ca nm. Phng php ny tn thi gian v khng tht mn cm. i vi vi
khun v trng lng tng c th l rt nh, thm ch phi ly tm ti vi trm ml mi
s lng xc nh trng lng sinh khi kh.
Phng php nhanh hn, mn cm hn l dng phng php o c nh tn x nh sng.
Mc tn x nh sng t l thun vi nng t bo. Lc nng vi khun t n 107 t bo/ml
th dch nui cy s vn c, nng cng tng th c cng tng theo v lm cn tr nh
sng i qua dch nui. C th o tn x nh sng bng quang ph k
(spectrophotometer). mt mc hp th nh sng thp, gia nng t bo v gi tr
hp th nh sng c quan h tuyn tnh (hnh 14.9). Ch cn nng vi sinh vt t
ti nng c th o c l u c th dng phng php o c trn quang ph k xc nh s
sinh trng ca vi sinh vt. Nu hm lng mt s vt cht trong mi t bo l ging
nhau th tng lng cht trong t bo c tng quan trc tip vi tng sinh khi
vi sinh vt. Chng hn, thu t bo trong mt th tch nht nh ca dch nui cy,
ra sch i ri o tng lng protein hay tng lng nitrogen, c th thy s tng
qun th vi sinh vt l ph hp vi s tng tng lng protein (hay N). Cng tng
t nh vy, vic xc nh tng lng chlorophyll c th dng o sinh khi to; o hm
lng ATP c th bit c sinh khi ca cc vi sinh vt sng.
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Hnh 14.9: o s lng vi sinh vt bng phng php o c.
Thng qua vic o hp th nh sng c th xc nh c sinh khi vi sinh vt.
Khi s lng t bo tng ln s dn n vic tng c, mc tn x nh sng nhiu hn v
quang ph k s o c mc tng ln ca tr s hp th nh sng. Trn quang ph k c
hai thang chia : pha di l tr s hp th nh sng, pha trn l mc thu
quang. Khi tr s hp th nh sng tng ln th mc thu quang h xung
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45
5.2. Ln men lin tc Cc phng php nui cy lin tc c th l: - Phng php
n cp: nui vi sinh vt trong mt ni ln men, mi trng dinh
dng c b sung cng nh mi trng ln men rt ra khi ni ln men mt cch
lin tc vi cng mt tc . Phng php ny n gin, d ng dng vo sn xut i vi t
bo nm men thu sinh khi hoc sn phm l cc cht chuyn ho gn trc tip vi s
pht trin ca t bo.
- Phng php nhiu cp: Vi sinh vt c nui h thng ni ln men t lm nhiu
cp. Ni th nht c dng cho vi sinh vt pht trin tt nht, cc ni sau cc t
bo tit ra cht chuyn ho. Mi trng dinh dng mi c b sung vo ni th nht v
t ln lt chy vo ni tip theo.
Trong cc h thng h ca phng php nui lin tc th ni ln men thng xuyn
c cung cp thm dung dch dinh dng mi, v cng vi mc nh vy, mi trng b s
dng mt phn v cc t bo c rt i. Vic khuy v thng kh nhm trn u cht cha
trong ni ln men (h thng ng nht). Nh vy cc t bo trong ni ln men lun
lun sinh trng theo hm s m v lun lun tn ti trong cng nhng iu kin
sinh l. Tuy nhin, cc t bo ang phn chia v cc t bo khng phn chia cng
tn ti v khng c s sinh sn ng b.
H thng lin tc c iu khin bi cc yu t ho hc chemostas. Khi chuyn t
trng thi ny sang trng thi khc th trng thi cn bng mi t c sau mt thi
gian. Nh vic tng tc dng vo m sinh trng c th c tng gn tc cc i. Tc
pha long (D) v tc sinh trng () l bng nhau trong phm vi ca tc pha
long tiu chun.
Cc h thng lin tc c ngha cng nghip. c im ca nhng h thng ny l ch,
cc t bo li trong h thng hoc a tr li , trong khi mi trng chy i khng
ngng. V cc t bo ch hot ng trong mt thi gian nht nh nn sau mt thi
gian no cn phi thay th hoc b sung chng. Thc cht th h thng ny l s ko
di pha cn bng ca s nui gin on nh vic a c cht vo mt cch lin tc. Cc t
bo, hoc c gi li trong h thng nh trng hp ca vi khun acetic sinh trng
trn v bo g ca phng php ln men nhanh, hoc c tch ra v a tr li nh
trong sn xut bia ru. Trong vic lm sch nc thi, cc m vi khun cng b gi
li trong cc b bn sng. Mt kiu khc l cho dng dung dch dinh dng chy vo
nhng vng nm. l kiu nui ni ca h thng lin tc kn. quy m phng th nghim,
cc h thng c kim tra, trong t bo v c cht c tch ring bng cc mng hoc
dng c lc (ni ln men - mng).
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46
Hin nay vic nui lin tc c ng dng nhiu trong cng nghip sn xut sinh
khi v cc sn phm ln men. Vic sn xut cc cht trao i bc mt v bc hai cng
nh cc enzyme thng c tin hnh theo cch khng lin tc.
u im ca phng php nui cy lin tc: - Gim bt thi gian lm v sinh thit
b, kh khun v lm ngui. - Gim bt th tch ca ton b thit b. - Lao ng d
dng v c kh nng t ng ho cc thao tc. - Tng hiu sut ca ton b qu trnh
cng ngh nh chn lc tt nht cc iu kin
thao tc. Nhc im: - i hi cn b v cng nhn thnh tho chuyn mn. Khi
hot ng, cng mt lc
phi c cc dng nng lng cn thit, gi thnh cao i vi t ng ho v dng c o
lng hin i.
- Trong qu trnh nui cy t bo vi sinh vt c th c nhng t bin bt ng
xy ra lm hng c qu trnh.
- Phi v khun tuyt i trong ton b thi gian thao tc. V trong qu
trnh nui lin tc to ra cc iu kin ti u cho chng nui cy th cng ti u i
vi nhiu loi tp khun.
- i vi cc vi sinh vt sinh h si nh nm mc v x khun rt kh tch h si
mt cch v khun v c bit l hiu sut chuyn ho thng thp hn so vi nui cy
tng m vi nhng chng sn ra cht chuyn ho khng gn vi s pht trin.
Hin nay vic nui lin tc c ng dng nhiu trong cng nghip sn xut sinh
khi v cc sn phm ln men. Vic sn xut cc cht trao i bc mt v bc hai cng
nh cc enzyme thng c tin hnh theo cch khng lin tc.
u im ca phng php nui cy lin tc: - Gim bt thi gian lm v sinh thit
b, kh khun v lm ngui. - Gim bt th tch ca ton b thit b. - Lao ng d
dng v c kh nng t ng ho cc thao tc. - Tng hiu sut ca ton b qu trnh
cng ngh nh chn lc tt nht cc iu kin
thao tc. Nhc im:
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47
- i hi cn b v cng nhn thnh tho chuyn mn. Khi hot ng, cng mt lc
phi c cc dng nng lng cn thit, gi thnh cao i vi t ng ho v dng c o
lng hin i.
- Trong qu trnh nui cy t bo vi sinh vt c th c nhng t bin bt ng
xy ra lm hng c qu trnh.
- Phi v khun tuyt i trong ton b thi gian thao tc. V trong qu
trnh nui lin tc to ra cc iu kin ti u cho chng nui cy th cng ti u i
vi nhiu loi tp khun.
- i vi cc vi sinh vt sinh h si nh nm mc v x khun rt kh tch h si
mt cch v khun v c bit l hiu sut chuyn ho thng thp hn so vi nui cy
tng m vi nhng chng sn ra cht chuyn ho khng gn vi s pht trin.
Trong cc phn trn chng ta xem xt vic nui cy phn m (batch
cultures) trong cc h thng kn, tc l khng c chuyn b sung cht dinh
dng, cng khng thi loi cc sn phm c hi sinh ra trong qu trinh sng.
Giai on logarit ch duy tr qua vi th h sau chuyn vo giai on n nh. Nu
nui cy vi sinh vt trong mt h thng h, trong qu trnh nui cy thng xuyn
b sung cht dinh dng v thi loi cc cht cn b th c th lm cho mi trng
lun gi trng thi n nh. l h thng nui cy lin tc (continuous culture
system). Trong h thng ny s sinh trng ca vi sinh vt lun gi c trng
thi logarit, nng sinh khi vi sinh vt lun gi c n nh trong mt thi
gian tng i di.
Gi th ta c mt bnh nui cy trong vi khun ang sinh trng, pht trin.
Ta cho chy lin tc vo bnh mt mi trng mi c thnh phn khng thay i. Th
tch bnh nui cy gi n nh. Dng mi trng i vo b p cho dng mi trng i ra
vi cng mt tc . Ta gi th tch ca bnh l v (lit), tc dng mi trng i vo l
f (lt/ gi). Tc (hay H s) pha long c gi l D (f/v). i lng D biu th s
thay i th tch sau 1 gi. Nu vi khun khng sinh trng v pht trin th
chng s b rt dn ra khi bnh nui cy theo tc :
= dX/dt = D.X
X l sinh khi t bo
Ngi ta thng dng hai loi thit b n nui cy lin tc vi sinh vt. l
Chemostat v Turbidostat.
Chemostat
Khi s dng Chemostat nui cy vi sinh vt ngi ta a mi trng v khun vo
bnh nui cy vi lng tng ng vi tc a mi trng cha vi khun ra khi
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48
bnh nui cy (xem hnh 14.10). Trong mi trng mt s cht dinh dng thit
yu ( nh mt vi acid amin) cn khng ch nng trong mt phm vi nht nh. V
vy tc sinh trng ca vi sinh vt trong h thng quyt nh bi tc mi trng mi
c a vo h thng v nng t bo ph thuc vo nng cc cht dinh dng c hn ch.
Nhp i mi cht dinh dng biu th bi nhp pha long D (dilution rate). Tc
lu thng ca cht dinh dng (ml/h) c biu th bng f v th tch bnh nui cy l
V (ml):
D= f/V
Chng hn nu f l 30ml/h v V l 100ml th nhp pha long D l 0,30h-1. C
s lng vi sinh vt v thi gian th h u c lin quan n nhp pha long (hnh
14.11). Trong mt phm vi nhp pha long tng i rng th mt vi sinh vt
trong h thng l khng thay i.. Khi nhp pha long tng ln, thi gian th h
h xung (tc sinh trng tng ln), khi cht dinh dng hn ch b tiu hao ht.
Nu nhp pha long qu cao th vi sinh vt b loi ra khi bnh nui cy trc
khi kp sinh si ny n bi v lc nhp pha long cao hn tc sinh trng ca vi
sinh vt. Nng cc cht dinh dng hn ch tng ln khi nhp pha long tng cao
vi c t vi sinh vt s dng chng.
Hnh 14.10: Nui cy lin tc trongChemostat v Turbidostat
Hnh14.11: H thng nui cy lin tc (Chemostat)
Khi nhp pha long rt thp th nu tng nhp pha long s lm cho c mt t
bo v tc sinh trng u tng ln. l do hiu ng ca nng cht dinh dng i vi
nhp sinh trng (growth rate). Quan h ny c lc c gi l quan h Monod
(Monod relationship). Trong iu kin nhp pha long thp , ch c t i cht
dinh dng c cung cp th t bo phi dng phn ln nng lng duy tr s sng ch
khng dng sinh trng, pht trin. Lc nhp pha long tng ln, cht dinh
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49
dng tng ln, t bo c nhiu nng lng c cung cp, khng nhng duy tr s
sng m cn c th dng sinh trng, pht trin, lm tng cao mt t bo. Ni cch
khc, khi t bo c th s dng nng lng vt qu nng lng duy tr (maintenance
energy) th nhp sinh trng s bt u tng ln.
Hnh 14.12: T l pha long trong chemostat v sinh trng ca vi sinh
vt
5.1.4. Thit b nui cy vi sinh vt trn mi trng lng
Nui cy vi sinh vt sn xut cc sn phm ca cc cht hot ho sinh hc l qu
trnh tinh vi v phc tp nht thu nhn cc sn phm tng hp vi sinh. Tng hp
sinh hc cc cht hot ho sinh hc do vi sinh vt to ra ph thuc vo mt s
yu t nh nhit , pH ca mi trng v canh trng pht trin, nng ho tan, thi
gian nui cy, kt cu v vt liu thit b.
Ph thuc vo cc phng php ng dng nh gi hot ng thit b ln men dng cy
chm vi sinh vt v c chia ra mt s nhm theo cc du hiu sau:
Theo phng php nui cy - cc thit b hot ng lin tc v gin on. Theo
tit trng - cc thit b kn v cc thit b khng i hi kn nghim
ngt. Theo kt cu - cc thit b ln men c b khuch tn v tuabin, c my
thng gi
dng quay, c b o trn c hc, c vng tun hon bn ngoi; cc thit b ln
men dng thp, c h thng gi kiu phun.
Theo phng php cung cp nng lng v t chc khuy trn, thng gi cc thit
b cung cp nng lng cho pha kh, pha lng v pha tng hp.
Trong cng nghip vi sinh thc t hu nh tt c cc qu trnh nui cy sn
xut ra
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50
cc cht hot ho sinh hc c tin hnh bng phng php gin on trong cc iu
kin tit trng.
Cc thit b ln men nui cy vi sinh vt trong iu kin tit trng Nui cy
cc vi sinh vt phn ln c tin hnh trong cc iu kin tit trng.
tit trng ca qu trnh c m bo bng phng php tit trng thit b ln men,
cc ng ng dn, cm bin dng c; np mi trng dinh dng tit trng v ging cy
thun chun vo thit b ln men c tit trng; khng kh tit trng thng gi
canh trng v cht kh bt tit trng; cc dng c cm bin tit trng trong thit
b ln mn kim tra v iu chn cc thng s ca qu trnh ; bo v m kn trc ca bc
huyn o, cc ng ng cng ngh v ph tng qu trnh nui cy
4.1.4.1. Thit b ln men cbo trn c hc dng si bt Dng thit b ln men
ny c s dng rng ri cho cc qu trnh tit trng
nui cy vi sinh vt - sn sinh ra cc cht hot ho sinh hc. Thit b ln
men c th tch 63 m3. Dng thit b ln men ny l mt xilanh ng
c ch to bng thp X18H10T hay kim loi kp c np v y hnh nn (hnh 7).
T l chiu cao v ng knh bng 2,6:1. Trn np c b dn ng cho c cu chuyn o
v cho kh bt bng c hc; ng ni np mi trng dinh dng, vt liu cy, cht kh
bt, np v thi khng kh; cc ca quan st; ca a vi ra; van bo him v cc
khp ni cm cc dng c kim tra.
Khp x 16 y ca thit b dng tho canh trng. Bn trong c trc 6 xuyn
sut. Cc c cu chuyn o c gn cht trn trc. C cu chuyn o gm c cc tuabin
8 c ng knh 600 1000 mm vi cc cnh rng 150 200 mm c nh v 2 tng, cn
tuabin h th ba c gn cht trn b si bt 13 phn tn cc bt khng kh. B si
bt c dng hnh thoi c lm bng nhng ng t l. phn trn ca b si bt c khong
2000 3000 l theo kiu bn c.
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Hnh 7. Thit b ln men vi b o trn c hc dng si bt c sc cha 63 m3:
1- ng c; 2- Hp gim tc; 3- Khp ni; 4- bi; 5- Vng bt kn; 6- Trc;
7- Thnh thit b ; 8- My khuy trn tuabin; 9- Btrao i nhit kiu ng
xon; 10- Khp ni; 11- ng np khng kh; 12- My trn kiu cnh qut; 13- Bsi
bt; 14- My khuy dng vt; 15- ; 16- Khp tho; 17- Ao; 18- Khp np liu;
19- Khp np khng kh
ng c - b truyn ng lm quay trc 6 vcc c cu o trn 8, 12, 14. S dng
b gim tc v b dn ng c dng in khng i iu chnh v cp s vng quay trong
gii hn 110 200 vng/ pht.
Thit b ln men c trang b o 17, gm t 6 8 . Mi c 8 rnh c ch to
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52
bng thp gc c kch thc 12060 mm. Din tch lm vic ca o 60 m2. B mt
lm vic bn trong 45 m2 gm ng xon 9 c ng knh 600 mm vi s vt 23 khi
tng chiu cao ca rut xon 2,4 m.
Thit b ln men c tnh ton hot ng di p sut d 0,25 MPa v tit trng
nhit 130 1400C, cng nh hot ng di chn khng. Trong qu trnh nui cy vi
sinh vt, p sut bn trong thit b 50 kPa; tiu hao khng kh tit trng n 1
m3/(m3/pht). Chiu cao ct cht lng trong thit b 5 6 m khi chiu cao ca
thit b hn 8 m.
tin li cho vic thao tc v trnh nhng sai lm cn dn vo thit b s ch
dn thao tc (hnh 10.2).
m bo tit trng trong sut qu trnh (gi c hi), cc trc ca c cu chuyn
o phi c vng bt kn. Cc vng bt kn c tnh ton hot ng p sut 0,28 MPa v p
sut d khng nh hn 2,7 kPa, nhit 30 2500C v s vng quay ca trc n 500
vng/ pht. Nh cc vng m ny m ngn nga c s r r mi trng hay s xm nhp
khng kh vo khoang thit b v tr nh ra ca trc.
Vng bt kn khi tip xc vi mi trng lm vic c ch to bng thp X18H10T
vX17H13M2T, cng nh bng titan BT-10. Thi gian hot ng n nh ca cc vng
ny khng nh hn 2000 h khi tui th 8000 h. o hng knh cho php ca trc
trong vng m kn khng ln hn 0,25 mm, o chiu trc ca trc khng ln hn
0,250.
sn xut ln cc cht hot hosinh hc bng tng hp vi sinh, vic ng dng cc
thit b ln men cthtch 63 m3 lkhng kinh t.
Thit b ln men c th tch 100 m3 c sn xut c. Loi ny thuc thit b
xilanh c b dn ng di cho c cu o trn. C cu o trn vi hai svng quay ca
trc - 120 v180 vng/ pht. Theo du hiu v kt cu n gn ging vi thit b ln
men c th tch 63 m3. Bo v vng bt kn ca trc bng ca van du, c tit trng
nhit n 1400C. Ngoi ra cn c bt kn d phng m mt cch t ng khi trc ngng
hot ng, nhm bo v vng bt kn chnh ca trc v cho php thay i vng bt kn
chnh trong qutrnh nui cy khng ph hu tit trng ca canh trng.
Trn trc lp ba my khuy o kiu tuabin dng m vi ng knh t 820 n 1100
mm. Thit b ln men c b mt trao i nhit bn trong v bn ngoi thi
nhit.
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53
Hnh 8. S ch dn thao tc ca thit b ln men:
1- Hi vo; 2- Khng kh tit trng vo; 3- Khng kh tit trng hay hi vo
vng bt kn; 4- Thot hi hay khng kh tit trng ti bsi bt; 5- Hi hay
khng kh tit trng vo thit b phn trn; 6- Thi hi hay khng kh tit trng
ti bly mu thnghim; 7- Thi hi hay khng kh tit trng; 8- C cu ng nhnh
cvan iu chnh bng kh ng hc; 9- Np hi hay khng kh tit trng vo thit b
phn di; 10- Tho nc ngng; 11- Ap k; 12- Van; 13- ng tho; 14- Van
kho; 15- Van ly mu; 16- Np hi hay khng kh tit trng khi ly mu; 17-
on ng ni p k kim tra; 18, 25- Cc p k; 19- Van np vt liu cy; 20- Np
canh trng; 21, 23- Np dung dch chun; 22- Thi hi hay khng kh tvng bt
kn; 24- ng nhnh np dung dch chun; 26- Cung cp kh thi t thit b; 27-
Cung cp nc; 28- Van rt; 29- Van rt nc t o; 30- Van np nc lnh; 31-
ng nhnh np nc lnh; 32- Lc; 33- Ap k; 34- Van an ton; 35- Cm bin
nhit ; 36, 37- Cc dng cthcp o nhit v pH; 38- Cm bin pH met; 39-
Thit b ln men; 40- C cu lm sch khng kh
c tnh k thut ca thit b ln men c sn xut c:
Thtch, m3: hnh hc: 00 lm vic: 70
Din tch bmt, m2:
bn ngoi: 9 bn trong: 7
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54
Thit b ln men ca Hng Nordon (Php). Kt cu ca loi thit b ln men
ny
khc vi cc loi nu ch c cu phn o nm di trc gm 6 cnh iu chnh c tit
din hnh ch nht, cn c cu c hc kh bt nm pha trn gm hai cnh (tit din
hnh ch nht) c cc g cng. Khi nui cy nm mc, cc cnh ca c cu chuyn o c
nghing di mt gc 33 340. Hnh 10.3 m t s bt kn trc nh 6 lp m vng kht
c gia cng s bdung dch 0,5 % phenol tinh th.Cc lp p cht li trong ng
bc nh cc guging (vt cy). m vng kht 2 chn lp gia trc 1 v cc t l 3.
Hai khp ni 8 c dn ti cc l cc. Hi np theo cc khp ni ny tit trng cc
vng bt. Tit trng nhit 1350C trong 1 h. Nc ngng chy vo phn di v c
thi ra qua khp ni 9. Khi kt thc qu trnh tit trng khp tho nc ngng c
ng li vkhng kh tit trng qua khp 5 vo c cu bt kn. Trong thi gian ca
qutrnh nui cy, p sut khng kh c gi mc 0,2 0,4 MPa.
Sau khi tit trng thit b vhp sut n p sut kh quyn th np tng khng
kh tit trng to p sut 0,2 MPa, vch csau mi np nc lm lnh vo thit b.
Tho cht lng canh trng ra khi thit b nhkhng kh nn c tit trng.
Hnh 10.3. Bt kn trc ca thit b ln men:
p sut lm vic, MPa:
trong thit b: 0,29 trong ng xon: 0,4
Cng sut ca b dn ng, kW: 120/180 ng knh, mm: 3600
Chiu cao thit b vb dn ng, mm: 14270
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55
1- Trc; 2- m vng kn; 3- Cc t l; 4- Vca bnt kn; 5- Khp ni dn khng
kh tit trng; 6- ng lt p; 7- Guging; 8- Khp ni np kh; 9- Khp ni thi
nc ngng
Ghi ch:(1) Cng sut in c nu trn ch trong trng hp s dng thit b ln
men nui cy nm mc - cho sn phm amiloglucozidaza.
Cc thit b ln men c o trn bng kh ng hc v thng gi mi trng Cc thit
b m bn trong n c trang b cc vi phun, ng khuch tn, cc b lm si bt np
khng kh u thuc loi ny. Khng kh vo c s dng khuy trn canh trng, m bo
nhu cu oxy cho vi sinh vt v thi cc cht chuyn ho
to thnh.
Bng 2. c im k thut ca cc thit b ln men
ca Hng Nordon c o trn c hc
S vng quay ca c cu trnvng/pht
ng knh, Chiu cao, Cng sut ng Th tch,
m3
mm mm c, kW
2 T150 dn 500 2000 3260 7,5
3 250 1100 3910 18,5
15 170 1900 6350 22,5
32 175 2400 8299 30,0
60 160 2900 10650 225,0 (1)
120 120 2800 12150 225,0
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56
Hnh 9. Thit b ln men dng xilanh c o trn bng kh ng hc v thi kh
mi
trng: 1- Khp ni tho; 2- Thit b thi kh; 3- ng xon; 4- Ca; 5- Khp
ni
np khng kh; 6- Khp thi khng kh; 7- Khp np liu; 8- Cu thang; 9-
ng khuch tn; 10- Ao; 11- Thnh thit b; 12- ng qup
Thit b ln men dng xilanh. Thit b loi ny v kt cu bn ngoi tng t nh
thit b ln men c khuy trn bng c hc, nhng bn trong khng c c cu khuy
trn bng c hc. ng khuch tn dng xilanh 9 c ming loa y, c lp bn trong
thit b. My thng gi 2 c lp theo ng tm ca thit b. Nh cc cnh hng, khng
kh c p sut c a vo my thng gi theo tip tuyn n tn phu trn lm cho nh
tng khng kh - cht lng chuyn ng xoy. Nh tng tun hon lin tc theo vng
khp kn bn trong theo mp bin ca xilanh, vng khng gian gia tng trong
v tng ngoi thit b, sau mt ln na li ln trn qua ming loa. Vic chuyn o
v thi kh mnh do to ra vng tun hon bn trong. thi nhit sinh l c kt qu
hn, ngoi o 10 cnhiu ngn cn b sung b mt lm lnh ca ng khuch tn 9.
Kt cu ca thit b ln men c tnh ton cho hot ng di p sut d.
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57
c tnh k thut ca thit b ln men c o trn bng kh ng hc.
Th tch ca thit b ln men, m3: 25,
49, 63, 200
p sut lm vic, MPa: 0,2 0,3
H s cha y: 0,5
Tc thot khng kh tthit b thng gi, m/s: 25
Tiu hao khng kh, m3 cho 1 m3 canh trng vi sinh vt: 0,5 0,2
Loi ny c th tch lm vic nh hn so vi cc thit b ln men o trn bng
c
hc, c hot ng vi mi trng ln bt mnh. Chng c p dng trong nhng trng
hp khi ging sinh vt khng cn phi khuy trn mnh v nht khng ln.
Cc thit b ln men dng ng. Loi thit b ny dng tng cng trao i khi,
gim tiu hao n v ca khng kh nn tit trng v tng tc tng hp sinh hc cc
cht hot ho.
Kt cu ca cc loi thit b ln men cho php thc hin qu trnh nui cy chm
khi vn tc di ca dng mi trng bng 2 m/s v ln hn.
Thit b ln men dng ng (hnh 10) bao gm khi tr ng 7, bn trong c c
cu chuyn o 8 c lp cht trn trc, ng tun hon, thit b thi kh, bung trao
i nhit 5, cc on ng np mi trng dinh dng, cc on ng np khng kh, rt
canh trng 13 v thi kh 16.
phn di ca ng tun hon c lp c cu chuyn i 8 dng vt. Cc cnh hng c
phn b trn v di vt: cc cnh trn thng ng, cn cc cnh di nghing.
H tun hon ca thit b ln men gm my phun c ni vi phn di ca thit b,
bm v cc ng ng. ng tun hon 15 c dng thit b trao i nhit dng ng c hai
ng gp. Bn trong ng gp trn c hai vch c c nh v trong mt phng xuyn tm,
cn bn trong ng gp di khng c vch. Ngoi ra b trao i nhit dng ng cn c
cc ng trao i nhit nm gia cc ng gp thng nhau v ni nhau bi cc tng
chn.
Bung trao i nhit c lp cht trong gi c hai bch v c th tho lp d
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58
dng sa cha. B kh bt bng phng php c hc 4 c g trn np thit b ln men
3. B dn ng cho thit b kh bt 2 v bn ca ra bng phng php c hc, u c lp
trn np.
Hnh 10. Thit b ln men dng trao i khi mnh BO - 40 - 0,6: 1- ng
cung cp kh thi; 2- B dn ng kn; 3- Np; 4- C cu kh bt; 5- Ming m vi
bung trao i nhit; 6- Hp khng kh; 7- Khi tr ng; 8- C cu chuyn o; 9-
ng np nc lnh; 10- ng c; 11- Bnh ai; 12- Truyn ng bng ai hnh thang;
13- C cu tho d; 14- ng thi nc; 15- Cc ng trao i nhit; 16- ng thi
khng kh; 17- ng kh bt;18- Ca quan st
Nh truyn ng bng ai hnh thang 12, m ng c 10 lm chuyn ng vt vi s
vng quay 280 350 vng/pht. m bo kn v tit trng trong qu trnh nui cy
cn b tr vng bt kn trn trc ca c cu chuyn o. C cu kh bt bng c hc c lp
trn trc ca b dn ng nh ng rng. Kh thot ra t cht lng c dn qua ng rng
trn. C cu ny gm b a hnh nn c g. iu khin ng c ti ch v iu khin t xa
ly tn hiu t bng iu khin.
kho st qu trnh nui cy vi sinh vt, trn tng thit b phn b su ca
quan st 8. Thit b c thit k hot ng vi p lc n 0,3 MPa.
Cc b phn t ng dng iu chnh cc thng s c bn ca qu trnh: nhit
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59
canh trng bn trong thit b - theo s bin i tiu hao nc lnh trong
phng trao i nhit; lng cht lng - theo s bin i thot ra ca cht lng
canh trng; nng ion hydro - theo s m v tt ca bm nh lng np kim hay
axit; nng oxy ho tan trong mi trng theo s bin i tiu hao khng kh tit
trng; tiu hao mi trng dinh dng - theo s bin i mi trng dinh dng vo
thit b v nng sinh khi - theo s bin i tiu hao mi trng dinh dng.
Kt cu ca thit b cng c kh nng kim tra tiu hao nc lnh, mc ng ho
nit, nng CO2 v O2, m khng kh, nhit v p lc trong nhng im ring bit ca
thit b.
Thit b ln men ny c th hot ng gin on hay lin tc. Khi kt thc qu
trnh tit trng v lm lnh ca thit b v ca cc c cu ph, th rt y mi trng
dinh dng tit trng v tin hnh cho hot ng c cu chuyn o thc hin tun hon
mi trng theo vng khp kn. Np khng kh nn mt cch lin tc qua thit b thi
kh vo khng gian gia tng v ng tun hon. Khng kh cun ht cht lng thnh
dng, p v ra thnh bt nh v c khuy trn mnh vi mi trng, to ra hn hp ng
ho gi.Chuyn ng quay ca mi trng c to nn trong ng tun hon nh cc cnh
hng, kt qu to ra vng xoy trung tm c hm lng kh cao.
Nh ma st cht lng vi phn g ca cc ng trong b trao i nhit m s chy
ri ca cc lp bin c duy tr. Khng kh thi c tch ra khi cht lng v c thi
ra qua ng lt rng ca thit b kh bt.
tng cng qu trnh cn np mi trng dinh dng vo thit b qua my phun. Bm
ht cht lng canh trng v y qua vi phun ca my phun, cho nn mc phn tn
ca cht dinh dng t c rt cao v to ra b mt tip xc ca cc pha rt ln. S
tun hon nhiu ln ca canh trng trong vng khp kn vi cc bmt nh hnh tt,
bo m hiu sut cao ca qu trnh v bo m tnh ng nht ca hn hp trong khng
gian vng tun hon. Bung trao i nhit bo m tt tc chy ca tc nhn lnh cao
lm cho h s trao i nhit ln. B trao i nhit kiu chm ng trong ng gp cho
php tng b mt n v lm lnh khong 10 ln ln hn khi truyn nng lng qua tng
thit b. H s truyn nhit c tng ln mt s ln v t gn 3900 W/(m2 K).
c tnh kthut ca thit b ln men dng ng:
H s cha y: 0,6 0,7
Th tch, m3: 40
Lng mi trng c np, m3: n 28
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60
Ap sut, MPa:
trong tng: 0,6
trong phng trao i nhit v trong o ngoi: 0,3
trong thit b: 0,1 0,6
Cng sut b dn ng, kW:
cho c cu khuy trn: 125
cho c cu kh bt: 40
S vng quay ca trc, vng/pht:
cho c cu khuy trn: 350 v200
cho c cu khbt: 1500
Kch thc c bn, mm: 4600260012000
Cc thit b ln men khng i hi tit trng cc qu trnh nui cy vi sinh
vt
Cc qu trnh nui cy sn sinh ra cc nm men gia sc thuc cc qu trnh
nui cy vi sinh vt khng tit trng. Theo kt cu cc thit b ln men, sn
xut nm men tng t nh cc thit b sn xut enzim, cc khng sinh chn nui,
cc amino axit v cc sn phm tng hp khc, nhng khng c s bo v hi v khng
kh ca trc quay v mt s b phn kt cu. Trong nhiu trng hp sn xut nm men
gia sc, ng dng cc thit b c s dng trong cc qu trnh tit trng.
Cc thit b ln men c o trn bng kh ng hc v ng vin tun hon bn
trong
Cc thit b nui cy nm men dng phng php bm dng bng kh nn ca h thng
Lephrancia c ng vin tun hon bn trong c ng dng ph bin nht. Trong sn
xut nm men thy phn thng ng dng cc thit b loi ny c sc cha 250, 320,
600 v 1300 m3. Kt cu cc thit b ln men khng c cc thit b c hc kh bt.
Bt c kh di trng lc ca ct cht lng khi tun hon.
Khng kh vo thit b theo ng trung tm vo chu, ti y hn hp kh - cht
lng c to thnh t nc hoa qu np vo v t cht lng phn di thit b. Hn hp
trn c chuyn ng theo ng khuch tn bn trong. Mt phn khng kh c tch ra
khi bt v thi ra kh quyn qua l np thit b, cn mt phn khc cng vi bt
h
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61
xung theo ng rnh vng gia ng khuch tn v tng. Khi chuyn ng xung di
bt b kh. bi tun hon t cao 1,5 2 th tch cht lng hot ng trong mt pht.
Cc thit b cng nghip c chiu cao 12 15 m. Bt dng cao ln 10 12 m. Tin
hnh lm ngui thit b ln men bng ti nc tng ngoi v np nc vo o ca ng
khuch tn. Tiu hao khng kh cho 1 kg nm men kh l 20 m3.
c tnh k thut ca cc thit b ln men cng nghip hot ng p sut kh quyn
c gii thiu bng 10.2.
Bng 3. c tnh k thut ca cc thit b ln men c o trn bng kh ng hc v
khi kh sn xut nm men gia sc
Th tch ca thit b, m3
Cc ch s
320 500 600 1300
Nng sut theo lng nc
20 30 30 35 55 62
hoa qu chy, m3/h
pH 4,5 pH 3,54,5 pH 4,24,5
Mi trng
n 5000 9000 1400016000 18000
Tiu hao khng kh, m3/h
p sut d ca khng kh,
0,6 0,75 0,4 0,6
kg lc / cm2
B mt lm lnh ca o
ng khuch tn, m2
30 503=1
50 58 504=200
Kch thc c bn, mm
570013350 760011200740014175 1100014500
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62
Thit b ln men hnh tr c b phn bm dng bng kh nn vi sc cha 1300 m3
Thit b loi ny c dng nui cy nm men mt cch lin tc trong nc qu.N gm c
v thp hn, y hnh nn ct v np hnh nn c l chnh gia (hnh 11).
Hnh 11. Thit b ln men hnh tr c b phn bm dng bng kh nn vi sc
cha
1300 m3
Bn ng khuch tn 7 c lp bn trong thit b to ra bn dng tun hon c lp.
Khng kh nn c y qua ng gp 2 vo cc ng trung tm ca mi ng khuch tn, cui
ng trung tm c cn v chu 8.
Thng phn phi c t trn np thit b, dch ln men, nc qu, nm men v nc
amoniac cho vo cc ng khp ni 3, 4, 5. Tt c cc cu t c trn li v to ra
mt dung dch dinh dng v theo cc ng ng c ng knh 100 mm chy xung di cc
chu ca thit b thi kh.
Hn hp dinh dng khi chy trn qua mp chu c khuy trn vi khng kh thot
qua khe di chu. Nh tng khng kh - cht lng c to thnh dng ln theo ng
khuch tn n tm chn 6 th b ph v v chy xung di. Dng thit b ti dng ng
gp lm lnh tng ngoi thit b.
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63
Thit b ln men dng thp Cc thit b ln men ny bao gm loi a v loi
khng c cc c cu chuyn o
nm ngang. S khc bit ca loi thit b ny so vi cc loi thit b c nu cc
phn trn l tr s t s gia chiu cao v ng knh rt ln. Thit b dng thp c
nhiu trin vng bi kt cu n gin, kh nng tng cng qu trnh sinh tng hp v
cng sut n v ln. u im v kt cu ca thit b dng thp l khng c cc phn quay
chuyn ng v din tch chim ch nh.
Thit b ln men dng phun. Thit b ln men ca c vi s trao i khi mnh.
C th tch n 10003, s dng phng php cc tia ngm.
Hot ng ca thit b (hnh 10.7) c m t di y: bm ly tm c chc nng kh
kh, y cht lng n ca vo ca thit b ln men dng ng. Cht lng chy xung dc
theo tng ng dng dng vng khuyn. Dng chy ri u cui nm ngang mc b mt
cht lng ca hn hp b tht li trong tit din ngang ca ng v t chy thnh
dng tia to ra vng p sut thp.
Khi to hn hp ng ho vi cht lng th khng kh c ht qua l nh khoang
trong vng p sut thp. Cht lng si bt ( dng tia xm nhp t do, do d tr
nng lng ng hc) n y ca thit b ln men, to ra trng ri mnh trong dung
dch canh trng. Cc bt kh t y thit b ni ln bmt, mt ln na qua trng ri
c to ra t cc tia xm nhp t do.
Nh h thi kh tng t nh th c th m bo cung cp oxy cho cc thit b ln
men loi ln c th tch n 2000 m3, khi cng khuy mnh.
c tnh k thut ca thit b ln men dng phun nui cy nm mc c gii thiu
bng 5.
Khi tc chuyn ng ca cc dng tia 8 12 m/s v p sut khng i th s phn
tn ca khng kh s t c tt. Nh tc ng phun vng vo ca dng, nh chuyn ng im
tng ca thit b v nh o trn cc bt kh m thc hin vic la chn thch hp cho
xung lng ca dng np t do, nhm bo m s khuy trn mnh canh trng nui cy.
Cc bt khng kh trong lung hu nh hon ton n y thit b, cn khi ni ln bmt
thit b chng b ph hu bi trng ri Trong trng hp gim lng cht lng tun
hon th s phn tn khng kh c tng ln ng k v n c phn b u theo ton th tch
thit b. Tc trao i kh tng tuyn tnh vi s tng dng cht lng tun hon v
tiu hao nng lng trong mt khong hot ng rng. Cho nn qu trnh thi kh c
th iu chnh bi tc truyn kh. Trong cc thit b c kt cu c nu trn, nhu cu
v nng lng np khng kh rt nh v nng lng ca dng tun hon s bo m ri cn
thit trao i khi. Nhng iu kin cn
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64
thit trao i khi mnh trong thit b l: ri cao, s phn tn khng kh tt,
thi gian c mt ca khng kh trong canh trng lu v ng ho mi trng
cao.
B Hnh 12. Thit b ln men dng phun: 1- Ca khng kh vo; 2- ng ng
khng kh thi; 3- Hm tho nc; 4-
Tng thit b; 5- ng ng cp; 6- ng ng ht; 7- Bm tun hon
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65
Bng 5. c tnh kthut ca cc thit b ln men dng phun sn xut c
Th tch ca thit b ln men, m3
Cc ch s
200 400 1000
Nng sut ca thit b ln men (tnh theocht kh tuyt i), kg/h 250
370
180 350
Th tch cht lng si bt, m3
80 130 400
Dung lng ca thit b, tn
2500 4400
Nng sut ca cc bm tun hon, tn/h
30 26 30 110
Bi s tun hon ca cc bm, th tch trong 1 h
S lng bm
1 2 10
125 135 210
220 2200 Tiu th nng lng in cho cc bm thi kh v ng ho, kW.h
Tiu hao khng kh trong khoang si bt cp sut gim, Nm3/h 3600 5000
60000
Kch thc,mm
ng knh 6000 8000 11500
1050
chiu cao phn tr 7500 8000
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66
Bm tun hon l b phn chnh ca ton h. Phng php lung ngm c hiu qu c
bit i vi cc qu trnh c tc trao i khi cao. Trong trng hp t hp tng ca
cc thit b hay khi phn chia bn trong thit b c sc cha ln ra thnh 2 3
phn v tt c cc ngn c ni li nh cc mng rt mi trng theo chy t trn xung
mng di, mi ln chy nh th c bo ho oxy ca khng kh.
Lng cht tun hon c hn ch bi s cp liu ca bm chuyn. Khi phn b thnh
ba tng lng bm cn thit cho thit b mt tng vi chiu cao chuyn l bi s 3
th rt ngn c 3 ln. Bt c to thnh trong qu trnh thi kh cng c chuyn
xung di, cho nn c cu kh bt c nh v phn di ca thit b. Tin hnh thi
nhit sinh l trong b trao i nhit c bit.
ng dng dng thit b trn nui cy vi sinh vt trong iu kin tit trng rt
phc tp v do kh khn v kn ca cc bm tun hon, nhng tin li i vi qu trnh
tit trng bng hi. Nhng c nhng u im: c cu n gin, dung lng ln, bo m
thi kh mnh v m bo truyn khi m khng cn c cu o trn, lm cho kt cu ny
tr nn c trin vng trong cng nghip vi sinh.
Cc thit b ln men c h thng gi dng phun Loi thit b ny c ng dng nui
cy chng nm men c bit trn mi
trng dinh dng cha parafin lng. Thit b ln men -50. Kt cu ca thit
b c dng dung lng xilanh ng vi sc
cha 800 m3 (h s cha y 0,4), c chia thnh 12 ngn (hnh 10.8). Mi
ngn c c cu khuy trn v thi kh. Thit b c trang b cc b o trn thc hin
chc nng khuy trn pha lng v cung cp khng kh. Trong qu trnh quay ca b
o trn v tr thot cht lng, khng kh c ht vo, vng h p c to ra. Khi khng
kh ho mnh vo cht lng, lm bo ho oxy trong cht lng.
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67
Hnh 13. Thit b ln men -50: 1- Rnh vng; 2- ng thng gi; 3- B kh
bt; 4- Bphn ly; 5- Xilanh; 6- Dn
ng; 7- B trao i nhit; 8- ng khuch tn; 9- Cc xilanh; 10- C cu
phun
c tnh kthut ca thit b ln men -50:
Nng sut ca thit b tnh theo sinh khi kh tuyt i,tn/ngy 27,0
Nng sut thit b khi g t trung tm 13 ngn,tn/ngy: 30
Dng cht lng, m3/h: 37,5
Dung tch, m3:
khi cha hot ng: 800
khi hot ng: 320
Nhit hot ng, 0C: 32 34
Din tch bmt trao i nhit, m2: 2700 3000
Tiu hao khng kh, m3/h: 36160
Slng c cu thng gi: 12
Cng sut ng c, kW: 3,5
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68
Thit b nui cy nm men trn mi trng rn -76-900 nui nm men parafin.
Hin ti loi kt cu ny c thc nghim rng ri trong cc nh my sn xut cht c
cha vitamin v protein. Thit b ln men (hnh 10.9) gm v 1; vng tun hon
t l 2; ng khuch tn trung tm 5; cc c cu thi kh 3 c lp trong vng tun
hon t l v trong ng khuch tn trung tm; cc b trao i nhit 7 v b tch
git 4. ng c 6 dn ng cho cc c cu thi kh. Np vo thit b mi trng dinh
dng cha parafin, mui khong, cc nguyn t vi lng, nc amoniac, v tho
thnh phm ra khi b phn ly qua khp ni. Np khng kh thi cho canh trng
bng phng php t ht. Khi cc b thng gi sc kh cho mi trng th s trao i
khi c xy ra qua b trao i nhit to ra nhng dng ln xung.
V thit b c ch to bng thp khng g, hai lp, cn cc b trao i nhit, cc
c cu trao i kh vcc vch ngn - bng thp nguyn khi.
Hnh 14. Thit b nui cy nm men trn mi trng rn -76-900
c tnh k thut ca thit b ln men -76-900
Nng sut thit b, tn/ngy: 30 36
Dung lng, m3:
khi cha hot ng: 900
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69
khi hot ng: 450
p sut, MPa: 0,02
Nhit hot ng, 0C: 32 34
Mi trng, pH: 4,2 4,4
Din tch b mt trao i nhit, m2: 2700
Tiu hao khng kh ( iu kin bnh thng), m3/h: 54000
S lng cc c cu thi kh: 13
Cng sut ng c in, kW: 315
Kch thc c bn, mm: 17000170006500
Khi lng, tn: 535
Nhc im ca thit b ln men c h phun ch: trc thit b b rung ng; nhim
bn b mt trao i nhit v gim h s trao i nhit.
Thit b ln men trao i khi mnh Mc ch chnh ca loi thit b ny l tng
nng vi sinh vt trong dung dch
canh trng, tng iu kin thi kh v tng nng sut thit b. Thit b (hnh
15) l mt dung lng xilanh 17, bn trong lp xilanh hng 2. Hai
on ng 4 v18 nh v cho xilanh hng trong dung lng. on ng 18 c lp
cht n y v chia dung lng ra lm hai phng: phng 19 dng nui cy canh
trng, cn trong phng 20 tn dng b sung nguyn liu ban u. on ng 4 lp
cch mt y ca dung lng. Bn trong xilanh hng 2 v trong khng gian gia
tng dung lng v on ng 4 c b tr cc ng gp 16. Cc ng gp c lp cht bi cc
ng t l 21. Trong khng gian gia xilanh hng 2 v cc on ng 18 v4 c cc b
trao i nhit 1. np khng kh n cc ng gp trong phng 19 dng ng gp phn
phi 7, cn trong phng 20 - ng gp 5. phn trn ca dung lng c ng gp 14
thu nhn v lm kh bt, bn trong c lp cc a hnh nn 15. Khng kh thot ra t
phng 19 qua b tch kh 9. My kh bt bng c hc 12 vi b dn hng c lp t trn
cc a 15. Mi trng dinh dng c y vo thit b qua khp 6. Sinh khi c tho
ra khi thit b qua khp 11, cn khng kh - qua khp ni 8 v13.
Thit b hot ng nh sau: np hn hp dinh dng ban u vo phng 19 qua khp
ni 3, cn khng kh - vo thit b qua khp ni 6. Trong phng 19 xy ra nui
cy sinh khi. Tun hon v o trn cht lng c thc hin bi thit b bm dng
bng
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kh nn. T phng nui cy, cht lng canh trng chy qua on ng 12 vo phng
20, ti y xy ra tn dng b sung nguyn liu. Bn trong phng 19 v 20 dung
dch canh trng c thi kh nh cc ng c t nhiu l. Sinh khi tho ra khi
phng cng vi pha bt c to thnh phn trn ca phng. Sau bt ni ln theo cc
ng rnh gia cc a nn 15, c tch khi cht lng v c c li. Kh bt c c bng b
kh bt c hc 12 v tho ra qua khp ni 11. Thi khng kh khi phng 19 qua
khp ni 8 nh b tch kh 9, cn khi phng 20 - qua khp ni 13.
Hnh 15. Thit b cy ln men trao i khi mnh Kt cu ca cc c cu thi kh
trong my phun kin tuabin My phun kiu tuabin l loi kt cu ht hai tng
c cc ca trn v di
np v thi dung dch. Loi ny hot ng nh sau: khng kh vo c trn vi cht
lng, khi thot ra th khng kh c hng ln trn v sau khi qua b trao i
nhit c chia ra lm hai dng. Khi i qua phn trung tm ca c cu tun hon,
dng th nht vo ca trn ca c cu phun, cn dng th hai hng xung di theo
ng vin ca c cu tun hon v khi chuyn ng di y gi th vo ca di.
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My phun kiu tuabin c cc vng t l Loi kt cu ny c dng thi kh v khuy
trn mi trng ging khi nui
cy vi sinh vt, c bit l nm men. Nhm mc ch n gin ho kt cu ca my
phun kiu tuabin, c cu ph dng cht lng c dng vng t l, c lp gia cc cnh
ca qut v cc phn to ng vin ca v my.
My phun (hnh 10.11) gm v10 c lp cht trong ng thng rng kh 1
vi
cc phn to ng vin 6 hnh thnh vi phun 4; cc rnh phn b11 bn trong
vi phun hn hp kh - cht lng; qut c lp trong v gm cc a 9 v 8, cc rnh
3 gia cc a, c cu cho dng cht lng c dng vng t l 5 c lp cht gia cc
cnh qut v cc phn l ca rto. Cc cnh ca my bm dc trc y cht lng canh
trng v dn vo phn chy 7 ca my phun, ti y cc vng t l 5 s to ra nhiu
vng nh. Cc dng ny s phun vo khng kh c y t qut v trong vi phun 4 s
to ra hn hp hi - cht lng, nh cc cnh khuy 11 hn hp b phn tn trong
cht lng. Dng kh - cht lng c phn tn chy ra ngoi. Loi ny cho php lm n
gin ho kt cu ca my phun, lm tt hn s phn tn khng kh v tng tc ht oxy
trong cht lng.
Hnh 16. My phun dng tuabin c cc vng t l
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My phun kiu tuabin c cc vi My phun ny c c trng bi qu trnh trao i
khi tt hn, bng cch nng
cao mc phn tn kh trong cht lng v tng lng kh xm nhp vo cht lng.
thc hin c iu ngi ta lp cc vi trong my theo ng knh ngoi ca cc a qut
nhm ph hu dng cht lng. Khi nhng on vo ca cc cnh phun hn hp kh - cht
lng c phn b gia cc vi. My phun kiu tuabin hnh 10.12 gm co v 8 vi cc
on ng ng vin 2 hnh thnh vng, vi phun 4 c lp cht trn trc rng ca ng
thng kh th 1; cc cnh phn b 10 bn trong vi phun phun hn hp kh - cht
lng v qut gn trong v gm hai a 5, 6 vi cc cnh 3 gia cc a. Theo ng
knh ngoi ca cc a ngi ta phn b cc vi 9 ph hu cc dng cht lng. Nhng on
vo ca cc nhnh 10 phun hn hp kh - cht lng c phn b gia cc vi. Cht lng
ban u c hng ti cc vi 9 nh cc cnh 7, ti y cht lng c phn chia ra mt s
dng, chng tip xc vi khng kh vo t qut v y vo vi phun 4, ri tip tc
phn tn kh trong cht lng nh cc cnh 10, 9. Sau cht lng bo ho khng kh
c thot ra ngoi.
Hnh 17. My phun dng turbin c cc vi
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5.2. Ln men b mt trn mi trng rn Trong phng php nui b mt hay nui
ni cc c th tn ti b mt mi
trng, do m cc t bo hng v khong khng kh c cung cp y xy. cc vng
nm, cht dinh dng ca mi trng ch c hp thu nh cc t bo chm v c chuyn vo
si nm kh sinh. S to vng trong phng php nui b mt dn ti mt trng thi
sinh l c ngha quan trng i vi vic sn xut cc cht trao i nht nh ca nm,
v d nh sn xut acid citric hay cc enzyme. Tuy nhin ngi ta vn c gng t
n trng thi sinh l tng ng vi nui cy chm.
Phng php nui cy ny thng thch hp cho mt s nm mc v x khun. Vic nui
thng c tin hnh trn cc khay phng xp chng ln nhau v trong cc bung cha
v trng ng kn, ging c cy vo bng cch thi bo t vo bn trong bung cha.
Mt hnh thc khc l nui h si nm trn cc c cht rn nh la m, cm hoc la nc
trong cc thng quay chm. Phng php ny c dng sn xut mt s enzyme.
Theo phng php ny, ging vi sinh vt hiu kh sau khi cy s pht trin
trn b mt v dn dn lan xung pha di theo cc k h gia cc cu t thnh phn
mi trng. Vi sinh vt s dng xy ca khng kh h hp ng thi thi CO2 ra mi
trng xung quanh v to nhit. Phng php ny thng thch hp cho cc qu trnh
nui cy nm mc, mt s x khun v vi khun cng c th sn xut theo phng php
ny.
Nui cy vi sinh vt trn b mt mi trng rn hoc bn rn c c cht dinh dng
l cm c trn cc loi bt ng cc, u tng v mt s thnh phn dinh dng khc.
Ngun carbon cho mi trng dinh dng l cc loi ht nh ng, go, m, i mch, u
tng... c nghin v thnh mnh kch thc khong 1 - 3 mm. m ca mi trng
khong 55 - 60%. Khi vi sinh vt pht trin s thi CO2 gy hin tng to
nhit lm nng v kh mi trng. Cn phi thng gi, phun m hoc lm m trc tip
gi cho m tng i ca khng kh khong 90%.
Nhc im ca phng php: - Tn nhiu din tch mt bng, kh c kh ho v t ng
ho. - Chi ph nhn cng, in nc... cho mt n v sn phm cao.
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5.2.1. K thut chun b mi trng rn Theo phng php ny ging vsv hiu kh
sau khi gieo cy s pht trin trn b mt v dnc dn lan xung pha di theo
cc k h gia cc cu t thnh phn mi trng. Mi trng nui cy b mt l mi trng
rn xp. Vi sinh vt pht trin s dng xy ca khng kh h hp lm tc nhn xy ha
trong cc qu trnh bin i sinh ha, ng thi thi CO2 ra mi trng xung
quanh v ta nhit. Mi trng dinh dng sau khi thanh trng c ti trn khay
sch vi chiu dy t 3 5 cm v nui nhit thch hp trong bung nui cy c m
khng kh l 90%. Ngun cacbon cho mi trng dinh dng y l cc loi ht nh ng
go m, i mch, u tng ..c nghin v thnh mnh c kch thc 1 3 mm, cng vi cm
go, cm m (hai loi cm ny ng vai tr l ngun cacbon v ngun cc cht sinh
trng) v tru. Cm tru trong mi trng cn c tc dng lm xp tng hiu khi cho
vi sinh vt nui. Chun b mi trng bng cc trn cc thnh phn u vi nc sao
cho m khong 55 60% v c hp thanh trng.
Cy ging vi sinh vt t dch nhn ging hoc rc cc bo t vo khi mi trng
thanh trng v ngui, thnh ng vi gi, sau ti ra khay vi chiu dy 2 5 cm
(cng mng hiu kh cng tt). Khi vi sinh vt pht trin s thi CO2 to nhit
ra xung quanh lm nng v kh mi trng, h si lm cho mi trng kt thnh tng.
Khi cn phi thng gi, phun m hoc lm m trc tip, lt khi mi trng nui cy
hoc b nh. Bung nui cy c cc gi k khay, c b phn gia nhit v lm mt, b
phn phun m bng nc gi m tng i ca khng kh l 90% trnh lm kh mi trng.
Nui cy b mt
Phng php b mt thng thch hp cho cc qu trnh nui nm mc, mt s trng
hp l x khun nhng nhm vi sinh vt sinh trng thnh h si. Cng c mt vi
trng hp nui cy vi khun theo phng php ny.
Nui vi sinh vt trn b mt mi trng rn hoc bn rn, c cht l cc loi bt
ng cc, u tng v mt s thnh phn dinh dng khc. Ngy nay phng php b mt s
dng cng ngh hin i hn v c trang b cc thit b o lng c th iu khin c qu
trnh cho hiu sut ln men cao. Song phng php nui cy b mt vn c nhiu
nhc im:
- Tn nhiu din tch mt bng
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- Kh c kh ho v c bit l rt kh t ng ho c ton b qu trnh.
- Chi ph nhn cng, in nc cho mt n v sn phm cao.
Hnh IV.1: Bung nui cy b mt
1.Gi khay 2.Van hi nng iu ho nhit
3.H thng phun nc thnh bi 4.Qut
5.Lc kh 6.ng thng kh vo 7.ng thng kh ra
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Hnh IV.2: S nui cy vi sinh vt theo phng php b mt trn khay
A. Cng on chun b lm mi trng
B. Chun b nc sch lm m mi trng C. Lm sch kh cp cho phng nui
cy
D1.Khu vc ra v lm sch gi st D2. Khu vc kh trng v ra khay
E. Gi vi khay c mi trng nui cy
Ngun cacbon cho mi trng dinh dng y l cc loi ht nh ng, go, m,
bobo, i mch, u tng c nghin v thnh mnh c kch thc khong 1 -3mm, cng
vi cm go, cm m v tru. Cm tru trong mi trng c tc dng lm xp tng hiu
kh cho vi sinh vt nui.
Cy ging vi sinh vt t dch nhn ging hoc rc cc bo t vo khi mi trng
thanh trng v ngui, thnh ng vi gi, sau ti ra khay vi chiu dy khong 2
5cm. Khi vi sinh pht trin s thi CO2, to nhit ra xung quanh lm nng v
kh mi trng, h si lm cho mi trng kt thnh tn. Khi cn phi
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thng gi, phun m hoc lm m trc tip, lt khi mi trng nui cy hoc b
nh. Bung nui cy gi m tng i ca khng kh l 90% trnh lm kh mi trng.
Nui cy b mt vi mi trng rn v xp ngy nay c ci tin nhiu trong qu
trnh: thay khay v bung nui cy bng thng quay c trc cho hoc thng b c
thi kh lin tc v iu khin nhit , m. Nhng ci tin ny lm tng nng sut ca
qu trnh rt nhiu.
5.2.2.Thit b nui cy vi sinh vt trn mi trng rn Nui cy vi sinh vt
trn cc mi trng ti th ht c nhiu u vic hn so vi nui
cy trn cc mi trng dinh dng lng. Nh tc tng hp ca cc enzim cao hn
5 6 ln, ngoi ra canh trng nhn c c m 40 50% (trong canh trng lng 80
95%), cho php tit kim ng k ngun nng lng sy. Tuy nhin n nay phng php
nui cy vi sinh vt trn cc mi trng dinh dng rn cha c ng dng rng ri
trong cng nghip do cha c nhng thit b tit trng c c kh ho ng tin cy.
Hiu sut v hot ho ca cc cht hot ho sinh hc, thi gian qu trnh nui cy
ch yu ph thuc vo nhng yu t sau: loi vi sinh vt, thnh phn cu t ca mi
trng dinh dng, lng v cht lng ca nguyn liu cy, nhit nui cy, mc thi
kh ca canh trng pht trin, cng o trn, trao i khi v trao i nhit. Vic
la chn dng thit b v nhng b ph tr m bo tt c nhng i hi ca cng ngh c
ngha quan trng nht.
Phn loi thit b nui cy vi sinh vt trn mi trng dinh dng rn nui cy
vi sinh vt trn mi trng dinh dng rn, ngi ta s dng cc loi
thit b c kt cu sau y: thit b nui cy vi sinh vt trn mi trng rn
dng phng c cc khay t l nm ngang vi kch thc 400800 mm, thit b c c kh
ho c khay ng t l, thit b c c kh ho dng 42, cc thit b bng ai tc ng
chu k v lin tc, t my nhiu phin tc ng lin tc vi s ng dng cc my rung
cng nh cc thit b dng trng quay. Nhc im ca cc thit b nui cy vi sinh
vt trn mi trng rn dng phng c cc khay nm ngang t l l khi lng lao ng
cho cc cng on qu ln, mc c kh ho cho cc cng on cng ngh thp v khng
trnh khi s tip xc ca cng nhn vi canh trng ca vi sinh vt. T cc kt cu
k trn, trong cng nghip thng ngi ta ng dng cc thit b c c kh ho c cc
chu c phn b ng, cng nh cc thit b dng trng quay v hnh thp. Cc thit b
dng trng quay v hnh thp c trin vng tt sn xut ln.
S tch lu mt lng ln cc ph thi nng nghip nh rm, v bng, v ht
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hng dng, ci ng, cc ph liu khi gia cng khoai ty, c ci ng, cy
ma... cho kh nng s dng chng thu nhn protein chn nui, l ngun rt in
cho sn xut xenluloza v tinh bt.
Tuy nhin nui cy vi sinh vt vi mc ch tng hp sinh hc protein khng
th s dng cc phng nui cy bnh thng, cc phng ny c sdng nui cy nm mc
trn mi trng dinh dng rn c chiu cao ca lp mi trng khng ln hn 3 5 cm.
Cc x nghip sn xut cht c c cha protein v enzim thuc dng sn xut ln,
cho nn i vi nhng nh my nng sut100 nghn tn trong mt nm i hi 210 nghn
chu. mc nh th cn phi s dng cc thit b tho mn cc yu cu sau: chiu cao
ca lp mi trng dinh dng khng nh hn 50 cm; kh nng to ra cc iu kin tit
trng; s bin i sinh hc ca cc cht dinh dng trong nguyn liu thnh
protein l cc i. Cc thit b sn xut cc sn phm trn c th gin on hay lin
tc. Cc thit b tc ng gin on thng dng hnh trng nm ngang, loi tr qu
trnh nui cy vi sinh vt c th thc hin trch ly cc cht hot ho sinh hc t
canh trng nui cy.
Cc thit b nui cy vi sinh vt trn mi trng rn c cc khay t l nm
ngang
Trong cc iu kin sn xut nui cy cc ging nm mc trn b mt trong cc
khay, ngi ta s dng cc phng tit trng, s lng cc phng ph thuc vo nng
sut tnh theo canh trng nm mc kh hng ngy. nh hng thng khi nng sut 1
tn/ngy cn 3 4 phng tit trng. i vi nh my c nng sut 10 tn/ngy s phng
l 30 40. Phng tit trng l bung kn c kch thc 1000028002100 mm vi hai
ca, mt ca ni vi hnh lang thi liu. Bn trong phng c ba on ng thng kh
np khng kh iu ho t mt hng, cn t hng ngc li- cc ng thi khng kh trong
phng. Din tch ca phng c tnh cho 18 20 gin c khong 9 10 khay cho mi
bn, quy i ra cm kh l100 kg. Khong cch gia cc gin 80 100 mm, gia cc
gin c khong cch rng 1000 1200 mm i li v cch tng 200 300 mm.
Cc b iu ho c lp c phn b trn cc phng tit trng nhm y khng kh c
nhit 22 320C, m tng i 96 98% vo phng. Khng kh tun hon c b sung 10%
khng kh sch t b iu ho chnh, cc hnh lang np v tho ca cc phng cn phi
cch ly cc phng bn cnh. iu thc hin c nh thng gi hai chiu khi trao i
khng kh nhiu ln (n 8 ln) v nhl m sch khng kh thi khi cc bo t.
Vic nui cy ging trong cc phng tit trng c s dng trong cc giai
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on u ca s pht trin sn xut ra cc ch phm enzim. Nhng tng to ra cc
thit b dng c kh ho c cc khay nm ngang khng mang li kt qu tt v tn
nhiu kim loi v nng sut thp.
Thit b c cc khay c phn b ng Thit b nui cy vi sinh vt trn mi trng
dinh dng rn kolovieva. Phng ca
thit b ny lb cha hnh hp bng kim loi c c nh trn cc tr nh h ging n
hi. Np lt c ng kn trn thit b, cn di y lt. Bn trong phng c khong 50
mm b tr hp ng tng kp t l, khng kh c y qua cc hp ny. Cc hc ca rnh ng
(c to ra gia cc hp) l nhng khay cha. Cc khay c y mt co nhm ngn cn s
vung vi mi trng khi np. Phng c trang b cc khp ni np hi, nc v thi nc
ngng. My rung c bt cht vo phng tho d canh trng nm mc. Kim tra v ghi
nhit c thc hin nh nhit k tip xc t ti mt trong nhng rnh nui cy v ni
vi b dn ng qut, rle s t ng tt v m qut.
Nhc im ca loi ny l nng sut nh, bin dng cc phng v thi canh trng
nui cy nm mc ra khi khay l rt kh khn, kn khi thi khng m bo v tiu
hao khng kh thi nhit sinh lln.
Phng nui cy vi sinh vt trn mi trng dinh dng rn c cc hp tho c v d
ti bng t ng ho.Thit b ny l s bin dng ca thit b kolovieva.Phng nui
cy l hm kim loi, trong c lp cc hp ng c th tho d hm c. Phng c lp trn
khung vi cc bnh v c th chuyn dch theo cc ray. c nh mt v tr xc nh
phng c trang b cht nh v. Khay c to nn do hai bn khay c khp ni phn
trn ca phng.Tay n iu chnh cc tm chn ph phn di ca cc khay. Thc hin
thng gi canh trng qua cc rnh phn b khng kh trong cc khay. C cu tho
d (hnh 9.1) canh trng nui cy ra khi khay c phn b trn phng nui cy v
gm nhng b phn c lin quan nhau c nh cc khay 2; c cu m cc khay c phn
b tng xng theo hai hng ca phng; c cu y phng n tm kim loi phng nm
ngang 6 c kp cht bng cc thanh ni ng 7 chuyn ng quay tnh tin. Cc b
phn nh v cc khung 2 gm hai trc (c cc cht) sp xp song song cn i vi
trc ngang ca phng. C cu m ca cc khay c hai mm quay vi cc thanh
truyn, thanh rng c kp cht trn cc thanh truyn c phn b t hai hng ca
phng v dng chuyn dch phng. Tt c cc c cu trn c lp cht trn sng 9. Sng
ta trn khung 3 nh ct 8. ng c in lm chuyn ng thit b. Phng cng vi
canh trng nui cy chuyn di theo ng ray 1 tho d v c nh v mt v tr nh.
Sau dng tay
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n m tm chn ca khay, cn tay gt m khay u theo tin trnh tho d. Khi
m ng c in, thanh rng c cht 5 bt u chuyn dch, phn di ca na khay dch
li ra. Sau c cu y bt u hot ng: tm kim loi 6 h xung di, y canh trng
nui cy ra khi khay v c nng ln. Khi tm kim loi nng cao hn khay, sng
bt u chuyn dch theo khung 3 nh ct 8 vo v tr trn khung tip theo. Tr
chng 4 cng vi sng chuyn dch v khi tc ng ti cht, a n vng bin, ti y
khay c tho d theo th t.
Hnh 18. C cu tho d t ng canh trng nm mc trong cc hp ra khi phng:
1- ng ray; 2- Cht nh v; 3- Khung; 4- Trng; 5- Cht; 6- Tm kim loi
phng; 7- Thanh ni; 8- ct; 9- Sng; 10- a xch
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Khi thit b c 7 phng nui cy c th thu nhn 1200 kg ging nm mc trong
mt ngy. Cc phng nui cy c ch to bng hp kim nhm, sc cha ca chng 500
kg, kch thc c bn ca phng 160013001020 mm, khi lng 771 kg.
Dy chuyn t ng ho nui cy ging nm mc. Trn c s cc phng nui cy vi
sinh vt trn mi trng rn c cc hp tho d, tho ra qu trnh lp rp v vn hnh
dy chuyn cng ngh nui cy bng c kh ho v nhn c nhng ch phm enzim tinh
khit c cng sut 50 100 tn/nm, ph thuc vo dng ch phm sn xut. Dy chuyn
gm cc cng on: chun b mi trng dinh dng, nui cy, trch ly, lng, tch v
sy, tiu chun ho v gi ch phm. Giai on quan trng nht ca dy chuyn l
chun b mi trng dinh dng v nui cy ging nm mc, gm hai bng chuyn cng
ngh c lp nhau (hnh 9.2).
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Hnh 19. Cng on nui cy ging trn b mt: 1- Vng trn quay; 2- C cu y;
3- Thit b san; 4- Rnh np liu; 5- Bn np
liu ; 6- B tit trng cc phng nui cy; 7- C cu y; 8- Ra cc phng; 9-
Bn d liu; 10- Phng nui cy; 10- Bra khp cui cng; 12- Bng ti; 13-
Phng nui cy mi trng rn; 14- Bulng ghp; 15- ng ray
Trong mi bng chuyn u c b tit trng, ni khuy trn, 9 phng nui cy
trn mi trng rn trong ng hm kn vi h ng ray 15 chuyn dch lin tc cc
phng t cng on cng ngh ny n cc on cng ngh khc.
Vn chuyn cm v b c ci vo thng cha bng kh nn, ri cho qua vt ti vo
mt trong nhng ni tit trng. Sau khi np vo ni tit trng mt lng nc v
dung dch amoni sunfat nht nh ri trn u v tin hnh tit trng mi trng ch
t ng. Sau mi trng c a vo thit b khuy trn tit trng. Nc lm m mi trng
v huyn ph c ng ho vi lng 0,1 0,8% so vi khi lng ca mi trng dinh dng
cho vo thit b khuy trn trn. Sau khi khuy trn trong vng 3 5 pht, ca
np ca my trn t ng m ra v rt mi trng vo cc hp tho d c trong phng 13
di my trn trn bn np liu 5 ca giai on nui. Mi trng vo phng tit trng
qua rnh m di ng c dng hnh nn, rnh phn b mi trng vo 28 hp. S m cht
cc mi trng trong cc lp xy ra khi phng dao ng, sau theo ng ray t ng
chuyn vo ng hm ca phng nui cy 10. Cng on nui cy c trang b hai phng
nui cy 10 song song nhau, c 9 v tr thi kh, hai b phn np liu 3 v 4,
b phn tho liu 9, nghin ging, ra 8 v tit trng phng 6. Tt c cc b phn
ny ni nhau bi cc ng ray 15 c vng trn quay 1 v bi cc h thng vn chuyn
nm bng ti xch v c cu y bng thu lc 2. Vic vn chuyn cc
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phng t b phn ny sang b phn khc u tin hnh bng t ng. ng hm ca phng
nui cy c chia ra lm ba on: on u c phn b
lin tc cho 6 phng nui vi sinh vt trn mi trng rn s13, on th hai
cho hai phng v on th ba cho mt phng. Cc on trong phng nui c ng kn
bng cc ca kh ng hc c cc tm m cao su. Mi on c trang b hai ng khuch
tn phn b ngc nhau. Cc calorife v cc qut theo h tun hon khp kn. C
khong 3 h th cho phng nui cy c np liu vo ng hm, cn phng trc th t ng
chuyn dch n on tip theo. Cho nn c 9 phng nui vi sinh vt trn mi trng
rn c a vo ng hm ca phng nui.
cc on u vo thi k ca cc pha tin pht, khi xy ra sny mm bo t (thi
gian t16 18 h) trong phng phi gi nhit 33 350C. Vo thi k pht trin
(thi gian 16 h) cng ca dng khng kh c tng ln nhm bo m thi nhit v thi
cc sn phm chuyn ho to kh khi gi nhit ca mi trng 35 360C. on th ba
nui trong giai on tch lu enzim, dng h thng gi c tnh n gi nhit ti u
32 340C. Nhit ca khng kh trong mi on c iu chnh t ng theo chng trnh
cho.
Khi kt thc chu trnh nui, c cu 7 y phng 13 ra khi ng hm v a n bn
tho d 9. M c cu chuyn dch phng n bn tho d v xy ra s chuyn dch ca
phng n mt khong cch bng chiu rng ca hp. Khi tay n ca y hp v tay n
tho d hp t quay trn, v c cu y s y canh trng nui cy t hp n b nghin u
tin. Sau khi d ti, phng nui cy chuyn ng theo ng ray n bphn ra, ri
vo b tit trng.B tit trng l xylanh nm ngang c hai np m ngc chiu. Cc
np c y kn nh b p thu lc. Sau khi tit trng phng c lm lnh, sy bng
khng kh tit trng v t ng a n bn np liu, sau chu trnh cng ngh c lp
li. Dy chuyn cng ngh t ng ho lm tng mc cng ngh v ging sn xut, lm
gim thi bi v bo t.Tuy nhin n chim din tch ln lp t h vn chuyn v cc
phng nui cy, tn nng lng v kim loi, nng sut thp.
Thit b nui cy ging bng phng php tnh ng i vi cc iu kin sn xut ln
th cng sut n v ca thit b cn phi tng
ng k.Ngoi ra cng cn phi to ra cc thit b c nh nhm m bo kn ca tt
ccc cng on cng ngh, gim din tch v khi lng ring. Phng php nui cy
chng nm mc trn b mt tnh - ng lc hc l ch mi trng trng thi bt ng
(trng thi tnh), cn sau chu s chuyn ng tun hon cng bc, lm ti v chuyn
o (cc iu kin ng lc hc). Vi phng php ny khng th s dng cc
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khay c v mi trng s b ra ngoi. Mi trng dinh dng tit trng c trn vi
ging vi sinh vt a vo gin bng ti u tin ca phng nui cy. Khng kh c pha
trn s bvi hi nc bo ho hay l khng kh c iu ho y vo phng. Lng khng kh
v hi nc c tnh ton sao cho trong vng tnh c nhit ca hn hp hi - khng
kh 32 350C, cn m tng i- 96 98%.
Thi gian gi mi trng cy trn gin c xc nh trn c s ph thuc vo s sng
trong phng. Khi thi gian chung ca ging pht trin trong tt c cc gin
cn bng thi gian chung ca qu trnh nui cy ging (t 24 n 48 h). Qua
nhng khong thi gian nh nhau, sn phm c chuyn bng c kh t gin trn xung
gin di k cn. Cc gin trn c s dng cho pha nui cy u tin, cc gin gia
cho pha th hai v cc gin di cho pha thba. Cho nn mi trng dinh dng c
cy, khi chuyn t gin ny sang gin khc xy ra tt c cc giai on pht trin.
Vic np cc l mi trng dinh dng mi ln gin trn cng ca phng vi khong bng
thi gian c mt ca mi trng trn mi gin ca phng. Phng php nh th cho php
s dng ti a th tch hu ch ca phng, cho php tng cng qu trnh v lm d dng
iu kin lao ng. Khi chuyn t gin ny sang gin khc mi trng c lm ti nhm
tng cng cc qu trnh thng gi, thi cc sn phm chuyn ha to ra kh v nhn c
ging c hot ho cao. Cc iu kin trao i nhit cng c tt hn, cho php gim
tiu hao khng kh thi nhit sinh l. Vic nui cy cc ging vi sinh vt bng
phng php tnh - ng c kh nng tin hnh trong cc thit b dng bng ti vcc
dng khc.
Thit b nui cy vi sinh vt trn mi trng rn dng -42-. C cu bn trong
thit b tng t nh kt cu my sy dng -42- v c tt c cc b phn ph:
calorife, qut, xyclon v ng thng kh, cng nh c cu lt cc gin trong
phng v lm kn khu np mi trng n gin u tin. L sy t ng tc dng lin tc
-42- gm c phng sy, hai calorife, ba qut v ba xyclon (xem hnh
9.3).
Thit b (hnh 9.3) gm phng sy 7, hai calorife 4, ba qut 1 v 12 v 3
xyclon 2. Phng c khung kim loi 11 c bc bng st l v c bao ph lp cch
nhit. Bn trong phng phn b 20 gin nm ngang c nh, khong cch gia cc
gin theo chiu cao 120 mm. Mi gin c16 bn ring bit 8 vi kch thc 12060
mm, cc bn t ng quay mt gc 900 trong khong thi gian cho.
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Hnh 20. L sy dng ng -42- Khi sn phm c tho xung cc gin di cn cc
gin lt c quay v v tr
nm ngang ban u. Nh cc tm ngn bn trong m phng 7 c chia ra lm ba
phn nhm cho php s dng hp l s phn b tc nhn nhit theo cc vng sy.
Trong vng u phn trn ca phng c phn b 6 gin, trong vng th hai phn gia
- 8 gin v trong vng th ba vng di- 6 gin. phn sn pha trc ca phng c
cc ca 9 ni vi ng vo t do. Cc ng thng gi t hai qut 12, calorife 4 v
ng ra ca tc nhn nhit ti qut ht 1 (qut ht th ba) v ti cc xyclon 2 u
c gn phn sn pha sau. S quay cc bn ca gin c tnh n sao cho ton b thi
gian sy l 5 10 pht. Sn phm t c nghin cho lin tc qua thng cha vo
thit b np liu v c t ng ri u thnh lp nm gin trn ca phn sy. Bm ly tm
12 ht khng kh qua blc th 14 v lc tinh 13 ri y vo phng sy qua
calorife 4, ti y khng kh c un nng n 85 900C. T gin cui cng sn phm
th c np vo thng cha 10. Khi i qua cng hng vi vt liu sy trn cc
gin
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6, khng kh c hng theo knh chuyn tip gia cc gin lm thay i hng
chuyn ng (ngc chiu) v sau thi ra ngoi. Nhit khng kh sau khi qua
calorife trong cc vng c kim tra bng nhit k 3. Dng m k 5 o m ca khng
kh vo phng. Qut 12 y khng kh vo vng pha di ca mng sy vi nhit 60
700C nhm sy thm sn phm n hm m 10 12%. Qut x hi 1 ht khng kh thi qua
cc xyclon 2 v c thi vo kh quyn, cn cc ht ca vt liu sy c tch ra v
theo mc tch lu m thi ra ngoi theo chu k. Trc khi thi khng kh vo kh
quyn cn phi lm sch trong cc b lc th 14 v lc tinh 13. Vi mc ch thch
nghi cho my sy dng nui cy chng nm mc, khng kh c ht theo ng thng gi
c t cao hn sng mi thit b khong 4 5 m, c lc qua b lc th, lc vi khun
v c ho ln vi hi nc bo ho trong ng thng gi t c cc thng s cng ngh quy
nh (nhit 32 330C v m tng i 96 98%). S dng cc b lc vi khun lm sch
khng kh thi vi khun. Vo thi gian tit trng my sy th b lc ny ngng hot
ng. Trong tt c ba giai on, ch vo v ra ca khng kh u t cc nhit k t
ghi kim tra nhit v m ca khng kh v mi trng. Np mi trng dinh dng c
tit trng ln gin trn cng ca phng phi c bt kn. Bng ti vn chuyn phn b
mi trng theo gin. Nhit c thit lp vng hai v vng ba 27 290C. Cho nn
sau thi gian chuyn dch ca mi trng c cy theo tt c cc gin th s pht
trin ging nm mc v s tch lu cc enzim c kt thc. Mi trng nui cy nm mc
ra khi gin di cng ri vo b cha, sau em nghin v sy. 24 27 kg mi trng
tnh quy ra cm kh np vo gin di ca phng, v sau mt ngy c th nui n 300
kg canh trng nm mc. Khi kt thc nui cy phi ra phng thit b bng nc nng
v tit trng bng khng kh c un nng n 120 1300C. Thit b nui cy vi sinh
vt trn mi trng dinh dng rn kiu bng ai.
Thit b dng KCK (hnh 9.4) l t kim loi, bn trong c 4 5 nhnh bng ti
vn chuyn dng li, c ch to bng thp khng g vi cc mt li 21,5 mm v c cng
ra trn hai tang quay. Kch thc ca cc bng vn chuyn ph thuc vo dng my
sy. Mi bng ti hoc l c hp tc ring hoc l dng chung mt hp tc . Hp tc
thay i tc ca bng ti t 0,14 n 1,0 m/ph. Trn cc bng ti vn chuyn c cc
thanh nhm phn b ng u lp mi trng dinh dng c chiu cao t 30 n 100 mm.
lm ti mi trng, pha trn bng ti lp t cc trc c cc cnh hnh kim, c quay
cng hng vi bng ti. Vic lm ti c tin hnh khi chuyn ti mi trng t bng
ti trn xung bng ti di. Di cc nhnh khng ti ca bng ti vn chuyn t cc b
lm sch. Cc trc ca b lm sch c cc cnh nh cht cc thanh cao su, quay
ngc hng chuyn ng ca bng ti. Trong khng gian gia cc
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nhnh ca bng ti lp t cc calorife hi nc. i vi mi bc tng calorife
ca cc vng nui cy th nht v th hai u c cc
thng c bit chun b nc nng v c dng c iu chnh v kim tra nhit . Nhit
nc a vo calorife di cc nhnh mt v hai ca bng ti 35 400C, di cc nhnh
ba v bn 26 300C. Cc calorife ca cc nhnh bng ti 5 c th c un nng bng
nc nng thi ra t cc nhnh trn. Cc calorife u c khp ni cung cp hi nc
cn thit cho vic un nng khi ra, sy v tit trng. C ba vng c to ra
trong phng nui cy: vng trn c nhit mi trng 32 350C, vng gia c nhit
300C, vng ny xy ra thi nhit sinh l v vng di c nhit 280C. Thit b cn
kn hon ton v c lp trong phng cch ly. Trn thit b lp ng ht gi c chiu
cao 5 10 m cung cp v thi khng kh. Trn ng cp v ht cn lp t cc b lc lm
sch khng kh khi vi khun.
Dng bng chuyn nghing ng kn hoc l dng ng t chy t ni tit trng t
trn thit b chuyn mi trng dinh dng c tit trng n bng ti trn cng. Lng
khng kh cn n 1000 m3 cho 1 tn canh trng nm mc. Sau khi np mi trng
dinh dng c cy ging vo nhnh trn ca bng ti vn chuyn, tt b dn ng bng
ti v mi trng c gi trong thi gian 9 h. Sau n c vn chuyn n nhnh tip
theo ca bng ti, ng thi vi vic lm ti khi mi trng v cng c gili trong
9 h. Vo thi gian ny l mi trng mi c vo nhnh trn. Cho nn c qua 9 h mi
trng c chuyn xung nhnh di v qua 36 h tho canh trng nm mc dng thnh
phm.
Khi kt thc chu trnh nui cy, ra t hp nui cy bng nc nng vtit trng
bng khng kh nng nhit 120 1300C trong vng 2 3 h, sau lp li chu trnh
cng ngh. C th np liu 600 700 kg mi trng dinh dng (270 300 kg tnh
chuyn i ra cm ti dng kh) vi chiu cao ca lp mi trng 50 mm trn mt
nhnh bng ti ca my sy.
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Hnh 21. Thit b nui cy vi sinh vt trn mi trn dinh dng rn kiu bng
ai: 1- Qut; 2- B lc dng peca; 3- Lc vi khun; 4- My iu ho; 5- Phng
nui
cy; 6- Bng li; 7- B lm ti; 8- Calorife; 9- Khng kh; 10- Thit b
tit trng; 11- ng chy; 12- Bng chuyn
Thit b nui cy vi sinh vt trn mi trng rn rng rung Cc thit b c s
dng trong cng nghip u c da trn phng php ng
lc hc nui cy canh trng nm mc trong lp rung ng lin tc. Bn cht ca
phng php l ch: trong qu trnh nui cy mi trng dinh dng trong b phn vn
chuyn c nhng tnh cht c trng (tr nn linh ng hn, h s ma st gim v sc
cn gim xung). Xung lng dao ng s truyn cho lp mi trng ang vn chuyn v
mi trng chuyn sang trng thi l lng.
Ch vn chuyn bng phng php rung c c trng bi s i mi lin tc lp b mt:
mi trng tip xc vi bmt ca b phn ti vt, sau ri khi b mt, qua mt khong
thi gian n li ri xung, cui cng b chuyn dch mnh. Mi mt tiu phn ca mi
trng b chuyn ng lin tc trong vng 36 h, khi nhng tiu phn ring r nh
nht c thi mnh lm cho b mt hot ho ca mi trng tng ln hng ngn ln so vi
phng php nui cy tnh trong khay.
Nhit sinh l do vi sinh vt tch ra trong qu trnh pht trin log c
thot ra ngoi, do tiu hao khng kh iu ho gim xung t 20.000 n 500 m3
cho mt tn canh trng. ng dng phng php rung cho php tng cng cc qu
trnh trao i nhit, trao khi v tng hp vi sinh, cho php c kh ho tt c
cc cng on, cho php tng hot ho ca ging v t chc qu trnh c kt qu
cao.
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Thit b rung c th dng ng hay nm ngang. Thit b rung dng vt tc ng
lin tc c nng sut 3,5 tn/ngy (hnh 9.5) gm ni
tit trng dng rung v bn bng ti rung c ph kn dng mng 7. Ba bng ti
u tng ng vi cc vng pht trin th nht, th hai v th ba l phn nui cy
trong thit b, cn bng ti th t dng sy canh trng. Mi bng ti rung c
trang b b dn ng c lp vi my rung bt cn i.
Mi trng c sy t ni tit trng rung 3 vo mng nhn 6 ca bng ti rung th
nht v di nh hng ca xung lng rung truyn cho mng, c chuyn di t di ln
trn. T mng trn ca bng ti rung u tin, mi trng theo mng vo ng nhn di
ca bng ti rung. Bng ti rung th hai v kt cu khc vi bng ti rung th
nht ch ch: cc mng ca n c trang b o nc dn hi thot ra vo thi k pht
trin log ca vi sinh vt. Khng kh iu ho c y vo bng ti rung th hai dn
cc sn phm to ra trong qu trnh hot ng sng ca vi sinh vt. T mng trn
ca bng ti rung th hai, mi trng theo ng vo mng nhn di ca bng ti rung
th ba, c cu ca bng ti rung th ba tng t nh bng ti rung ban u. Tc
chuyn ng ca mi trng theo mng ca bng ti rung 23 mm/s, cn ng knh v s
vt ca tt c cc bng ti rung c tnh sao cho mi trng c chuyn ng lin tc
trong thi gian ca tt c cc qu trnh pht trin. T mng trn ca bng ti
rung th 3 canh trng ca nm mc c nui cy theo ng vo mng nhn di ca bng
ti th bn ri a i sy. Kt cu ca bng ti rung ny ging nh bng ti th hai,
nhng np nc c nhit 700C vo o ca mng v cp b sung khng kh c nhit 70
800C. Canh trng nui cy nm mc sau khi sy c d ti, cn khng kh sau khi
lm sch vi khun c a ra ngoi kh quyn. My iu ho np khng kh tit trng
thng gi vi mt lng 500 1800 m3 cho mt tn canh trng.
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90
Hnh 22. Thit b nui cy t ng ho dng vt tc ng lin tc: 1- Khung thng
cha; 2- Thng cha cm; 3- Ni tit trng rung; 4- Dn ng
rung; 5- Ni tit trng; 6- on ng np mi trng dinh dng c tit trng;
7- Bng ti rung dng vt; 8- Dn ng; 9- ng np mi trng n bng rung th
hai; 10- ng np mi trng n bng rung th ba; 11- ng np mi trng n bng
rung th t
c tnh k thut ca thit b rung nui cy vi sinh vt trn mi trng rn dng
vt:
Nng sut tnh theo thnh phm canh trng, tn/ngy
(khi thi gian pht trin 36 h): 3,5
Gc nng ca mng vt (theo ng knh trung bnh): 504
Bc mng, mm: 219,2
ng knh mng, mm:
ngoi: 2000
trong: 1000
trung bnh: 1500
Chiu rng mng: 120
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Chiu cao mng, mm: 500
Tn s dao ng, Hz: t 5 n 26
Bin dao ng, mm: 5
Gc hng dao ng: 8701 ; 890 30
Cng sut ng c, kW: 28 40
Kch thc c bn, mm: 510080007200
Khi lng, kg: 16.000
Thit b dng thp Thit b nui cy vi sinh vt v ng. Thit b dng thp nui
cy vi sinh vt
(hnh 9.6) gm v ng 15 c chia ra lm 6 khoang vi cc cnh hng tm c vi
phun khng kh 6 c lp trn trc rng 13 v vi cc tm t l 16 c g trn cc trc
quay 2. Thit b c ng xon lm lnh 5, ng gp np khng kh tit trng 4 v ng
gp thi kh 7. phn trn ca dung lng c ca np liu 14, cn phn di c ca tho
canh trng pht trin 1. Phn gia ca dung lng xy ra thi k pht trin log
ca vi sinh vt km theo tch nhit nn c trang b o lnh 17. B dn ng qua
bnh rng 12 lm cho trc 13 quay.
Np mi trng tit trng c cy ging qua ca 14 vo thit b tit trng s
b.Mi trng c phn b u trn din tch cc tm t l 16 ca khoang u tin nh cc
cnh 6 lp trn trc theo chiu cao ca thit b. Khi kt thc pha u ca qu
trnh (qua 6 h) cc tm t l chuyn vo v tr ng. Mi trng ri vo khoang hai
v cc cnh s gt thnh lp u trn b mt ca cc tm t l. L mi trng mi li c np
vo khoang u tin c gii phng. Qua 6 h, mi trng t khoang hai c tho vo
khoang 3, cn t khoang u vo khoang hai. Mt ln na khoang u li c np y.
Cho nn tt c 6 khoang ca thit b c np y. Qua 36 h sau khi np mi trng
vo khoang u, d canh trng v a gia cng tip theo. Qu trnh xy ra mt cch
lin tc. Trong tin trnh nui cy, khng kh c a vo thit b vi sinh vt h
hp. Dng nc trong rut xon 5 v trong cc o nc 17 thi nhit sinh hc do
vi sinh vt thi ra. Vic np nhit vo khoang trn cha mi trng mi c thc
hin bng phng php thi khng kh m c un nng khoang nm di qua lp mi
trng. Khi cn thit th np khng kh tit trng qua trc 13 v cc cnh 6 vo
thit b to dng ri. Tit trng thit b p sut 0,3 MPa trong vng 1,5 2 h.
Khi nui cy ging trong thit b kn v khi thng kh qua cc tm t l, dng kh
trong mi trng s gy ra s gim p sut v kt cu rng ca mi trng dinh
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dng. S chuyn ng ca kh trong trng hp ny khng phi xy ra dc b mt ca
lp mi trng m n lan rng trong khp th tch, kt qu l to nn ch thi khi c
kh nng trao i khi v trao i nhit bng i lu v khuch tn theo khp chiu
cao ca canh trng pht trin.
Hnh 23. Thit b nui cy vi sinh vt trong lp mi trng c chiu cao 300
mm
1- Ca tho liu; 2- Cc trc quay; 3- Gi ta; 4- ng gp np khng kh tit
trng; 5- ng xon lm lnh; 6- Cnh trc; 7- ng gp tho khng kh thi; 8- Np
; 9- Khp ni cm p k; 10- Khp ni; 11- ng thot kh; 12- Bnh dn
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ng dng phng php thi khi mi trng dinh dng cho php tng chiu cao ca
lp canh trng khong 10 ln hay ln hn v to ra nhng iu kin ng dng thit
b nui cy su. Tng chiu cao ca lp mi trng t 20 40 n 300 500 mm l mt
trong nhng hng chnh tng nng sut thit b cng ngh, khc vi cc dng thit
b c nu trn, tt c cc qu trnh v cng on cng ngh c c kh ho, loi tr s
tip xc ca cng nhn thao tc vi canh trng v cc sn phm chuyn ho ca
chng. Trong qu trnh nui cy, nhit , m mi trng v khng kh, s vng quay
ca my khuy, hm lng CO2 vO2 trong pha kh l nhng thng s cn iu
chnh.
Thit b nui cy lin tc cc chng nm mc Loi thit b ny m bo khuy trn v
lm ti tt c b dy ca mi trng trong
qu trnh nui cy, ngn nga kh ro ca cc lp bn trn, cng nh tng cng qu
trnh. Thit b nui cy nm mc (hnh 9.7) gm thng cha mi trng 1, thng
chun b vt liu cy 6, ni tit trng 2, c cu lm lnh v lm m mi trng 3, c
cu cy ging 4 v thit b nui cy 5.
Thit b nui cy (hnh 24) c dng thp c ngn bng nhng on ng tn vi