TY - JOUR
T1 - Enzymatic production of L-amino acids from the corresponding DL-5-substituted hydantoins by Bacillus fordii MH602
AU - Mei, Yan Zhen
AU - He, Bing Fang
AU - Ouyang, Ping Kai
PY - 2008/3
Y1 - 2008/3
N2 - 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.
AB - 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.
KW - Bacillus fordii MH602
KW - Carbamoylase
KW - Hydantoinase
KW - L-amino acids
UR - http://www.scopus.com/inward/record.url?scp=39649099581&partnerID=8YFLogxK
U2 - 10.1007/s11274-007-9485-5
DO - 10.1007/s11274-007-9485-5
M3 - 文章
AN - SCOPUS:39649099581
SN - 0959-3993
VL - 24
SP - 375
EP - 381
JO - World Journal of Microbiology and Biotechnology
JF - World Journal of Microbiology and Biotechnology
IS - 3
ER -