Screening and taxonomic characterization of D-amino acid aminotransferase-producing thermophiles

摘要

To acquire an industrially useful biocatalyst for the enzymatic synthesis and production of various D-amino acids, 1,300 thermophiles isolated from the soil of Korea were analyzed for D-amino acid aminotransferase (DAAT) activity. The enzyme activity was found from 110 strains of isolated thermophiles revealing its wide occurrence in thermophiles. Enzyme activity and thermal stability of the D-AAT producers were compared. Finally we have selected four thermophiles as producers of potent biocatalysts for the D-amino acid production; two thermophiles, Bacillus sp. LK-1 and LK-2, having higher specific activity and two thermophiles, B. stearothermophilus KL-01 and Bacillus sp. KLS-01, having higher thermal stability than the D-AAT producers. Taxonomic and physiological characteristics of the four isolated thermophiles were described herein.