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ExtracellularYarrowia lipolyticalipase Lip2 (YLIP2) demonstrated an (R)-enantiopreference for efficient resolution of (R,S)-1-phenylethanol by solvent engineering with different kinds of binary solvent. The enantioselectivity was significantly improved by the addition of 1, 4-dioxane. The reaction parameters including co-solvent concentration, reaction temperature, and the reaction time were optimized. When the reaction was carried out with n-hexane in the presence of 0.8% 1,4-dioxane at 50°C for 72 h, the enantiomeric excess of product markedly increased to 99.1% from 66% in pure n-hexane; the enantiomeric ratio was higher than 200, which was 500-fold compared with that in pure n-hexane. The results indicated that it is very important to design the proper co-solvents, especially to create appropriate micro-environment for YLIP2 for catalyzing the resolution of (R,S)-1-phenylethanol. [ABSTRACT FROM AUTHOR]

An enzymatic process using a packed bed bioreactor with recirculation was developed for the scale-up synthesis of 2-ethylhexyl palmitate with a lipase fromCandidasp. 99–125 immobilized on a fabric membrane by natural attachment to the membrane surface. Esterification was effectively performed by circulating the reaction mixture between a packed bed column and a substrate container. A maximum esterification yield of 98% was obtained. Adding molecular sieves and drying the immobilized lipase both decreased the water content at the reactor outlet and around the enzyme, which led to an increase in the rate of esterification. The long-term stability of the reactor was tested by continuing the reaction for 30 batches (over 300 h) with an average esterification yield of about 95%. This immobilized lipase bioreactor is scalable and is thus suitable for industrial production of 2-ethylhexyl palmitate. [ABSTRACT FROM AUTHOR]