ESCHERICHIA-COLI TRANSKETOLASE-CATALYZED CARBON-CARBON BOND FORMATION- BIOTRANSFORMATION CHARACTERIZATION FOR REACTOR EVALUATION AND SELECTION

The conversion of glycoladehyde and beta-hydroxypyruvate to L-erythrul ose and carbon dioxide rt as used as a representative condensation to determine the key data required for rapid process evaluation and the s caleup of useful transketolase-catalyzed biotransformations. The subst rates and product exhibited alkaline lability requiring control of rea ction pH. The holotransketolase was rapidly deactivated via oxidation and was unstable at pH values less than 6.5 and greater than 10.0. The strength of binding of the cofactors to the enzyme was low at all ope rational pH values with implications for enzyme immobilization. Glycol aldehyde was found to be toxic to the enzyme and consequently the role of substrate feeding strategies was examined. (C) 1998 Elsevier Scien ce Inc.