Abstract

A STUDY ON THE INFLUENCE OF MEDIA COMPONENTS ON MICROBIAL REDUCTION OF A KETONE

M .S. Sandhyavali*, S. R. Brahmani Priyadarshini, Cauvery Dutta
and V Murugan

ABSTRACT

Microbial transformations are gaining importance as alternative to chemical reaction in synthetic chemistry. Aspergillus flavus, isolated from soil was found to bring about maximum bioreduction of parachloroacetophenone in our earlier study. The present work was aimed at evaluating the carbonyl reductase enzyme expression by Aspergillus flavus with change in media composition like carbon source (glucose, mannitol, maltose, sucrose, lactose and glycerol) nitrogen source (peptone, malt extract, yeast extract, tryptone and beef extract), metal ions (zinc sulphate, copper sulphate, calcium chloride, ferric chloride and magnesium sulphate) and variations in pH and temperature of growth media. The enzyme activity was evaluated spectrophotometrically using NADH. The study revealed that maltose and magnesium salt has significant effect on the enzyme production in Aspergillus flavus. Different nitrogen sources used in the study did not show significant change in enzyme expression. pH 7.6 and temperature 30 ºC were found to be ideal for enzyme expression.

Keywords: Bioreduction, Aspergillus flavus, para-chloroacetophenone, carbonyl reductase, NADH.