Optimization of carbohydrate fatty acid ester synthesis in organic media by a lipase from Candida antarctica

✍ Scribed by Peter Degn; Wolfgang Zimmermann

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 103 KB
• Volume: 74
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.1139

✦ Synopsis

Abstract

The effect of solvents and solvent mixtures on the synthesis of myristic acid esters of different carbohydrates with an immobilized lipase from C. antarctica was investigated. The rate of myristyl glucose synthesized by the enzyme was increased from 3.7 to 20.2 μmol min^−1^ g^−1^ by changing the solvent from pure tert‐butanol to a mixture of tert‐butanol:pyridine (55:45 v/v), by increasing the temperature from 45°C to 60°C, and by optimizing the relative amounts of glucose, myristic acid, and the enzyme preparation. Addition of more than 2% DMSO to the tert‐butanol:pyridine system resulted in a reduction of enzyme activity. Lowering the water content of the enzyme preparation below 0.85% (w/w) resulted in significant decreases in enzyme activity, while increasing the water content up to 2.17% (w/w) did not significantly affect the enzyme activity. The highest yields of myristyl glucose were obtained when an excess of unsolubilized glucose was present in the reaction system. In this case, all of the initially solubilized and a significant amount of the initially unsolubilized glucose was converted to the ester within 24 h of incubation, resulting in a myristyl glucose concentration of 34 mg/mL^−1^. Myristic acid esters of fructose (22.3 μmol min^−1^ g^−1^), α‐D‐methyl‐glucopyranoside (26.9 μmol min^−1^ g^−1^) and maltose (1.9 μmol min^−1^ g^−1^) could also be prepared using the tert‐butanol:pyridine solvent system. No synthesis activity was observed with maltotriose, cellobiose, sucrose, and lactose as substrate. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 483–491, 2001.