Enhancement of epoxide hydrolase production by60Co gamma and UV irradiation mutagenesis of Aspergillus niger ZJB-09103.
An effective epoxide hydrolase (EH) production strain was mutagenized using60Co gamma and UV irradiation. Among positive mutant strains, the EH activity of C2-44 reached 33.7 U/g, which was 267% as much as that of the original Aspergillus niger ZJB-09103. Compared with the wild type, there were significant changes in morphology for C2-44, including the color of mycelia on the slants and the shape of conidial head. In addition, glucose and soybean cake were the optimal carbon and nitrogen source in terms of EH activity for the mutant C2-44 instead of soluble starch and peptone for the wild-type strain. The reaction time required to reach 99% enantiomeric excesses of (S)-epichlorohydrin from racemic substrate was shortened significantly by the mutant C2-44. This phenomenon was probably explained by the higher Vmaxfor hydrolysis of racemic epichlorohydrin by C2-44 compared with Aspergillus niger ZJB-09103.
Institute of Food and Medicine, Zhejiang Ocean University, Zhoushan, People's Republic of China.
Huo-Xi
HX
Jin
Institute of Food and Medicine, Zhejiang Ocean University, Zhoushan, People's Republic of China.
Xiao-Kun
XK
OuYang
Institute of Bioengineering, Zhejiang University of Technology, Hangzhou, People's Republic of China.
Zhong-Ce
ZC
Hu
D001234:Aspergillus niger / Q000201:enzymology / Q000235:genetics; D004851:Epoxide Hydrolases / Q000096:biosynthesis / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D005720:Gamma Rays; D016296:Mutagenesis / Q000528:radiation effects*; D014466:Ultraviolet Rays
D005656:Fungal Proteins; D004851:Epoxide Hydrolases
60Co gamma; Aspergillus niger; UV; epoxide hydrolase; mutant