US EPA

2938645 

Journal Article 

Catalytic transformation of HODAs using an efficient meta-cleavage product hydrolase-spore surface display system 

Qu, Y; Wang, J; Zhang, Z; Shi, S; Li, D; Shen, W; Shen, E; Zhou, J 

2014 

Yes 

Journal of Molecular Catalysis B: Enzymatic
ISSN: 1381-1177 

102 

204-210 

10.1016/j.molcatb.2014.02.014 

WOS:000335872900029 

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. 

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