Microbial transformations.

Although the use of microbial biocatalysts for chemical reactions pre-dates by a considerable margin the application of isolated enzymes for this purpose, considerable progress continues to be made in the use of whole-cell catalysts. The application of whole-cell biocatalysts in oxygenase-catalysed reactions, the reductions of carbonyl and nitro groups, and the hydrolysis of nitriles and epoxides, are all areas of continued development. In addition, the use of microbial transformations in the production of drug metabolites, carbohydrates, and amino acids is expanding. Methodological development such as the application of novel immobilisation techniques or the use of non-aqueous solvents continues to enhance the usefulness of microbial biocatalysts.