Studies on enzymatic conversion of lipids and enzymes catalyzing lipids conversions that have been carried out by the author for these 20 years are reviewed.
1) Enzymatic conversions of lipids. Various conversions involving fats and oils catalyzed by lipases or by phospholipase D are described. These include; hydrolysis of partial glycerides contained in the crude product of chemical hydrolysis of fat; factors affecting of intraesterification of ω-hydroxyfatty acid in benzene; interesterification of olive oil by immobilized dry fungus; acidolysis of fish oil to increase
n-3 poly unsatureted fatty acid content; glycerolysis of fats to produce monoacylglycerol; formation of pure phospholipids by the action of transphosphatidylation of phospholipase D.
An unique liquid-liquid contact mode membrane bioreactor system that is useful for fats and oils conversions has been developed. A novel concept, 'micro aqueous', has been proposed.
2) Biochemistry, production, and genetic engineering for enzymes catalyzing lipids conversions. Two assay methods of lipase's hydrolysis activity have been reexamined. Lipase produced by
Fusarium oxysporum has been purified and characterized. Esterase produced by
Bacillus stearothermophilus has been purified and characterized, and it has been found that it is stabilized by SH-protecting agent. Protein engineering focusing on the role of two cysteine residues involved in the esterase has been studied.
Both effective productions of
Pseudomonas lipase and
Bacillus esterase have been realized by automatic fed-batch cultures.
Gene encoding phospholipase D of
Streptomyces antibioticus has been cloned and characterized and proposed a domain that may be binding site of substrate.
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