Biotransformation of dicarboxylic acid by immobilized Cryptococcus cells

Altering the cell permeability by treating Cryptococcus neoformans with 1% (v/v) hexane stimulated the yield of transformation of n-pentadecane to the corresponding dioic acid, tridecane 1,13-dicarboxylic acid (DC-15); however, the biotransformation process was inhibited by the elevated levels of DC-15. To avoid product inhibition, a continuous process with immobilized cells was performed, and the result showed that the yield of DC-15 production was increased up to fivefold as compared with the batch type of DC-15 production. To integrate the product recovery process with the biotransformation, Amberlite XAD-2 resin was used for adsorbing DC-15 and configured as an external in situ product recovery system. The continuous process described in this study is adaptable for large-scale production of DC-15. (C) 1997 by Elsevier Science Inc.