L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014 3. Phylum Proteobacteria GRAM NEGATIVE BACTERIA Wide morphological and metabolic diversity. Clinical, environmental, and industrial relevance Phylum with highest number of cultured representatives 5 groups (based on 16S rRNA): a, b, g, d, and e
3. Phylum Proteobacteria. GRAM NEGATIVE BACTERIA Wide morphological and metabolic diversity . Clinical , environmental , and industrial relevance Phylum with highest number of cultured representatives 5 groups ( based on 16S rRNA ): a , b , g , d, and e. - PowerPoint PPT Presentation
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L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria
GRAM NEGATIVE BACTERIAWide morphological and metabolic diversity.
Clinical, environmental, and industrial relevancePhylum with highest number of cultured representatives
5 groups (based on 16S rRNA): a, b, g, d, and e
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
2. Phylum Proteobacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
- Very sensitive to environmentalstress (drying, sunlight, UV light…)- High incidence (STD, ETS) - Mild symptoms* in women(asymptomatic carriers). PID- Complications if untreated
Sexual contact
Mucous membranes of the genitourinary tract
Reasons?
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Enteric bacteria
Facultatively aerobic, gram negative rods• Fermentation of sugars to organic acids
• Some respire NO3- to NO2
- (never to N2)
Virulence factors and pathogenicity
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Escherichia
Warm blooded animalsGut microbiota (comensals)Pathogenic strains: E. coli enterotoxigenic (ECET) E. coli enteropathogenic (ECEP) E. coli enterohemorrhagic (ECEH) (STEC)
E. coli O157:H7 E. coli O104:H14
GastroenteritisHemolytic uremic syndrom (HUS)
Urinary tract infections (UTI)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
vitamin K
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacterias. Familia Enterobacteriaceae
Salmonella
Habitat: gastrointestinal tract of wild and domestic animals, birds, pets, and insects. Zoonosis.Main pathogenic serovars: S. typhimurium: salmonellosis (enterocolitis) S. typhi: typhoid fever
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Desulfo- (generally) or Desulfuro-They reduce sulfate/sulfur(acceptors)Final products: H2S
Strict anaerobes (anoxic environments)Group I:
Acetate cannot be used as donor
Sulfate reducing bacteria
Group II:
H2 and acetate can be used as donors
Sulfate reducing bacteria
Fixation of CO2 (acetil-CoA pathway)
Group III:
H2 or organic matter as donors
S and sulfite reducing bacteria (NEVER sulfate)
DonorsH2 O. M.
*Some sulfate-reducing bacteria are not delta-proteobacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.4. d-Proteobacteria: SULFUR AND SULFATE REDUCING BACTERIA
m.o.
NO3-
Mn+4
Fe+3
SO4-2
CO2
E’ (V
)
+0.8
-0.2
0
Stratification of electronic acceptorsLimited organic matterMost important metabolism: sulfate reductionCompetence (or not---) with methanogenic Archaea
Marine sediments
Consortia of SRB/methane oxidizing Archaea
O2
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: PURPLE BACTERIA
Meromictic lakes, microbial mats
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Metabolic diversity of nonsulfur purple bacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Microbial mats: stratification of microbial populations driven by environmental gradients
Images property of Fernando Santos
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: METHANOTROPHS
Methylotrophs vs. methanotrophs
Biotic and abiotic methane
Methanotrophs vs. methanogens
Where does the methane come from?
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Type I Type II
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: METHANOTROPHS (Methylo…)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Methane as energy source
Methane monooxygenase
Methano Methanol Formalhehyde CO2
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Ribulose monophosphate pathway
Serine pathway
Type IIType I
Methane as carbon source
Methane Methanol Formalhehyde biomass
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: RICKETTSIAS
a/g ProteobacteriaObligate intracellular parasites*Induce phagocytosis, do not survive outside hostsHighly specific energy metabolism*, synthesize few compoundsTransmitted by arthropod vectorsDamage to blood vessels
Epidemic tifus (Rickettsia prowazekii) Vector: human louse