Upload
cecily-shaw
View
228
Download
3
Tags:
Embed Size (px)
Citation preview
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
Immobilized cells for continuous ethanol fermentation
• Adhesion• Entrapment• Membrane reactor• Flocculating cells