Screening of Microorganisms Producing D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate

Abstract

Microorganisms producing D-β-acetylthioisobutyric acid from methyl DL-β-acetylthioisobutyrate were screened from stock cultures. The D-β-acetylthioisobutyric acid-producing ability was found in 15 strains belonging to the genera Pseudomonas, Agrobacterium, Enterobacter, Cellulomonas, Rhodococcus, Brevibacterium, and Torulopsis. A strain of Pseudomonas fluorescens, IFO 3081, was selected as the best microorganism. The cells having activity (558units/g of dry cells) could be easily prepared by cultivation at 25°C at pH 6.6 for 24hr in a glucose-containing medium. The D-form of methyl DL-β-acetylthioisobutyrate was selectively hydrolyzed with the cells so that D-β-acetylthioisobutyric acid (97.2% enantiomeric excess) was produced in a high yield.