Effects of water activity on reaction rates and equilibrium positions in enzymatic esterifications

✍ Scribed by Ingemar Svensson; Ernst Wehtje; Patrick Adlercreutz; Bo Mattiasson

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 737 KB
• Volume: 44
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260440502

✦ Synopsis

A technique of continuous water activity control was used to examine the effects of water activity on enzyme catalysis in organic media. Esterification catalyzed by Rhizopus arrhizus lipase was preferably carried out at a water activity of 0.33, which resulted in both maximal initial reaction rate and a high yield. When Pseudornonas lipase was used as catalyst it was beneficial to start the reaction at high water activity (giving the optimal reaction rate with this enzyme) and then shift to a lower water activity toward the end of the reaction to obtain a high yield. The apparent equilibrium constant of the reaction was influenced by the water activity of the organic solvent.