Biocatalytic Preparation of Chiral Alcohols with Green Micro Algae: Bio-reduction of Carbonyl Compounds by Chlorogonium Strains as a Novel Biocatalyst

Ishihara K., Oka S., Hayashi Y., Kitagawa Y., Kondo Y., Shimoda K., Masuoka N., and Nakajima N.

Chlorogonium strains were screened to examine the potential ability of microgreen algae  to  act  as  biocatalysts. Two  culture  media  (National  Institute  for Environmental Studies (NIES) recommended AF-6 medium and a synthetic AY medium) were tested for the use in the liquid culture of three algal strains. When static  cultured  in  the  AY  medium  containing  acetate  and  yeast  extract  under continuous  light  conditions,  these  strains  showed  promising  growth.  Thus,  the stereoselective reduction of various carbonyl compounds using these strains was investigated. This study discovered that these strains could reduce aliphatic and aromatic  D-keto  esters,  D-substituted  E-keto  ester,  and  aromatic  D-keto  amide. Based on the conversion ratio and stereoselectivity of the  yielded alcohols,  C. elongatum NIES-1357 strains cultured in the AY medium is a potential biocatalyst for  the  stereoselective  reduction  of  aliphatic  D-keto  esters,  2- chlorobenzoylformamide, and ethyl 2-methyl-3-oxobutanoate to the corresponding chiral alcohols in the presence of L-alanine.

Int. J. Curr. Microbiol. Appl. Sci.

11

4