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Indexed by:期刊论文

Date of Publication:2014-04-01

Journal:JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC

Included Journals:EI、SCIE

Volume:102

Page Number:204-210

ISSN No.:1381-1177

Key Words:Surface display system; meta-Cleavage product hydrolase; 2-Hydroxy-6-oxohexa-2,4-dienoic acid; (HODA); Catalytic transformation

Abstract:The accumulation of 2-hydroxy-6-oxohexa-2,4-dienoic acids (HODAs) in the process of aromatics transformation will hinder the mineralization rate. In this study, a novel type of biocatalyst, meta-cleavage product (MCP) hydrolase (MfphA and BphD) displayed on the surface of Bacillus subtilis 168 spores, was developed for the transformation of HODAs. The successful display of CotG-MfphA and CotG-BphD fusion protein on the surface of spore were confirmed by western blot analysis and activity measurement. The optimal transformation conditions by spore surface-displayed MfphA and BphD were found to be 70 C and pH 7. The thermal and pH stability analysis exhibited that spore surface-displayed MfphA and BphD were stable and retained more than 80% of relative activities even at 80 degrees C and pH 10. Meanwhile, recycling experiments showed that the conversion percentage of HODA by surface-displayed MfphA and BphD were not significantly decreased throughout the reutilization process, which still retained 45% and 70% at the tenth cycle, respectively. To the best of our knowledge, this is the first report concerning the B. subtilis 168 spore surface-displayed MCP hydrolases. The high activities and good recycle performance suggested that this novel biocatalyst system could serve as a suitable alternative for HODAs transformation. (C) 2014 Elsevier B.V. All rights reserved.