A whole-cell method was developed for the regioselective synthesis of arabinocytosine laurate . Among seven kinds of bacteria strains tested in the acylation reaction, Pseudomonas fluorescens gave the highest productivity and a higher 5'-regioselectivity than 99%. Compared with pure organic solvents, the use of organic solvent mixture greatly promoted the yield of whole-cell catalyzed reaction, but showed little influence on the 5'-regioselectivity. Of all the tested solvent mixtures, the best reaction result was found in isopropyl ether/pyridine followed by isopentanol/pyridine. However, the whole-cells showed much lower thermostability in isopropyl ether/pyridine than in THF/pyridine. To better understand the toxic effects of the organic solvents on P. fluorescens whole-cells and growing cells were further examined. Significant influences of organic solvents on the biomass of the cells were found, which differed from the type of the solvents used. SEM analysis visually revealed the changes in the surface morphology of whole-cells and growing cells cultured in media containing various organic solvents, in terms of surface smooth, bulges and changed cell sizes. Results demonstrated that organic toxicity to cell structure played an important role in whole-cell mediated catalysis.

Investigation of catalytic behaviors of whole-cell biocatalysts in synthesis of 5'�arabinocytosine laurate in organic solvents

248th National Meeting (2014)

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