IMMOBILIZATION TECHNIQUES. Advantages in the use of immobilization technique Easy re-use of the biocatalyst Reduced requirement of the growth of cells:

IMMOBILIZATION TECHNIQUES

Advantages in the use of immobilization technique

• Easy re-use of the biocatalyst• Reduced requirement of the growth of cells: avoid

the waste of nutrients, minimize the requirement of energy, so reduce the capital and running costs / reduce the environmental problems

• Easy isolation of products• Increased stability• Easy continuous operation

Methods for the immobilization • Carrier binding: adsorption, ion exchanger,

covalent bonding• Cross-linking• Encapsulation: gel entrapment, microcapsules

• Membrane reactor

Classification of immobilization materials

• Organic 1. Polysaccharides: agar, agarose, carrageenan, cellul

ose, pectate, Sephadex etc. 2. Protein: collagen 3. Synthetic polymers: phenolic resins, polyacrylamid

e, polysterene et.• Inorganic 1. Ungrafted: alumine, ceramics, ferromagnet, glass,

magnesia, silica, zirconia 2. Grafted: various coupling agents

Immobilized microbial cells (Fukui and Tanaka,1982)

• Immobilized treated cells• Immobilized resting cells• Immobilized growing cells • Immobilized cells for electrode

Using carrageenan as matrix (Tosa, T. et al., 1979)

Gelling conditions

Effect of gelling agents

Gel shape

Different catalysts

Hardening treatment

Comparison with polyacrylamide

Two-step procedure (Wada et al., 1979)

Typical procedures (Chibata et

al., 1986)

Production in large quantities (Hulst et al., 1985)

Beads diameter

Immobilized cells for continuous ethanol fermentation

• Adhesion• Entrapment• Membrane reactor• Flocculating cells

Adhesion

Entrapment

Membrane reactors

Flocculating cells

生物反應器實況 ( 福井三郎， 1986)

Co-immobilization (Hartmeier, 1984)

Genetically engineered microorganisms?

問題

• 利用固定化技術處理生物活性觸媒有那些好處？• 將微生物固定化的方法有那些？• 生物活性觸媒有那些固定化方法？每一種方法的優缺點為何？

• 選用 Ca-alginate 或 carrageenan 進行微生物固定化各有何優缺點？

• 下列名詞的內涵： Carrageenan 、 Co-immobilization 、 Gel entrapment 、 Resting cells