Abstract: The invention discloses a novel thermostable D-hydantoinase, and relates to the nucleic acid sequence, amino acid sequence and vector constructs of the enzyme. The thermostable D-hydantoinase of the invention shows about 45%-70% identity in amino acid sequence with other D-hydantoinases. The thermostable D-hydantoinase of the invention converts 5′-substituted D-hydantoinase to the corresponding N-carbamoyl-D- and/or -L-&agr;/&bgr;-amino acids, and retains at least 50% activity after 30 days at 50° C. In addition, the enzyme activity can also enhanced by certain divalent cations.

Abstract: The invention discloses a novel thermostable D-hydantoinase, and relates to the nucleic acid sequence, amino acid sequence and vector constructs of the enzyme. The thermostable D-hydantoinase of the invention shows about 45%-70% identity in amino acid sequence with other D-hydantoinases. The thermostable D-hydantoinase of the invention converts 5′-substituted D-hydantoinase to the corresponding N-carbamoyl-D- and/or -L-&agr;/&bgr;-amino acids, and retains at least 50% activity after 30 days at 50° C. In addition, the enzyme activity can also enhanced by certain divalent cations.

Abstract: The present invention relates to a method for recovery and purification of isoamylase by raw starch adsorption method. Various raw starches are used to recover the isoamylase produced by a bacterium such as Pseudomonas amyloderamosa. The method comprises using raw starch to adsorb isoamylase under conditions suitable for such adsorption and isolating the adsorbed enzyme. The isoamylase adsorption rate varied with the species of raw starch. Additionally, raw starch can be recycled.

Abstract: A method of converting cephalosporin C to glutaryl-7-aminocephalosporanic acid. The method including obtaining a cell preparation from a microorganism which produces D-amino acid oxidase, the preparation being a cell-free extract or a suspension of permeated cells; adding a D-.alpha.-amino acid to the preparation; after the adding step, heating the preparation at 50.degree.-75.degree. C. for 5-60 minutes; and incubating cephalosporin C in the preparation. Also disclosed are a method of converting cephalosporin C to glutaryl-7-aminocephalosporanic acid in the absence of exogenous H.sub.2 O.sub.2, and a method of screening for a D-amino acid oxidase-producing microorganism.