Rk. Mitra et al., ESCHERICHIA-COLI TRANSKETOLASE-CATALYZED CARBON-CARBON BOND FORMATION- BIOTRANSFORMATION CHARACTERIZATION FOR REACTOR EVALUATION AND SELECTION, Enzyme and microbial technology, 22(1), 1998, pp. 64-70
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.