PRODUCTION OF D-HYDANTOINASE BY HALOPHILIC PSEUDOMONAS SP. NCIM-5109

About 1000 bacterial colonies isolated from sea water were screened fo r their ability to convert DL-5-phenylhydantoin to D(-)N-carbamoylphen ylglycine as a criterion for the determination of hydantoinase activit y. The strain M-l, out of 11 hydantoinase-producing strains, exhibited the maximum ability to convert DL-5-phenylhydantoin to D(-)N-carbamoy lphenylglycine. The strain M-l appeared to be a halophilic Pseudomonas sp. according to morphological and physiological characteristics. Opt imization of the growth parameters revealed that nutrient broth with 2 % NaCl was the preferred medium for both biomass and enzyme production . D-Hydantoinase of strain M-l was not found to be inducible by the ad dition of uracil, dihydrouracil, beta-alanine etc. The optimum tempera ture for enzyme production was about 25 degrees C and the organism sho wed a broad pH optimum (pH 6.5-9.0) for both biomass and hydantoinase production. The organism seems to have a strict requirement of NaCl fo r both growth and enzyme production. The optimum pH and temperature of enzyme activity were 9-9.5 and 30 degrees C respectively. The biotran sformation under the alkaline conditions allowed the conversion of 80 g l(-1) DL-5-phenylhydantoin to 82 g l(-1) D(-)N-carbamoylphenylglycin e within 24 h with a molar yield of 93%.