Enzymatic production of L-amino acids from the corresponding DL-5-substituted hydantoins by Bacillus fordii MH602

Yan Zhen Mei, Bing Fang He, Ping Kai Ouyang

科研成果: 期刊稿件文章同行评审

5 引用 (Scopus)

摘要

Bacillus fordii MH602 was newly screened from soil at 45°C and exhibited high activities of hydantoinase and carbamoylase, efficiently yielding l-amino acids including phenylalanine, phenylglycine and tryptophan with the bioconversion yield of 60-100% from the corresponding dl-5-substituted hydantoins. Hydantoinase activity was found to be cell-associated and inducible. The optimal inducer was dl-5-methylhydantoin with concentration of 0.014 mol L-1 and added to the fermentation medium in the exponential phase of growth. In the production of optically pure amino acids from dl-5-benylhydantoin, the optimal temperature and pH of this reaction were 45-50°C and 7.5 respectively. The hydantoinase was non-stereoselective, while carmbamoylase was l-selective. The hydantoinase activity was not subject to substrate inhibition, or product inhibition by ammonia. In addition, The activities of both enzymes from crude extract of the strain were thermostable; the hydantoinase and carbamoylase retained about 90% and 60% activity after 6 h at 50°C, respectively. Since reaction at higher temperature is advantageous for enhancement of solubility and for racemization of dl-5-substituted hydantoins, the relative paucity of l-selective hydantoinase systems, together with the high level of hydantoinase and carbamoylase activity and unusual substrate selectivity of the strain MH602, suggest that it has significant potential applications.

源语言英语
页(从-至)375-381
页数7
期刊World Journal of Microbiology and Biotechnology
24
3
DOI
出版状态已出版 - 3月 2008

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