Haiyang Fan1, Lifeng Chen1, Huihui Sun2, Hualei Wang3, Qinghai Liu1, Yuhong Ren1, Dongzhi Wei1. 1. State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China. 2. Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences Qingdao, Qingdao Shi, 266071, Shandong Province, People's Republic of China. 3. State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China. hlwang@ecust.edu.cn.
Abstract
OBJECTIVE: To investigate the biodegradation of nitriles via the nitrilase-mediated pathway. RESULTS: A novel nitrilase, BGC4, was identified from proteobacteria Paraburkholderia graminis CD41M and its potential for use in biodegradation of toxic nitriles in industrial effluents was studied. BGC4 was overexpressed in Escherichia coli BL21 (DE3), the recombinant protein was purified and its enzymatic properties analysed. Maximum activity of BGC4 nitrilase was at 30 °C and pH 7.6. BGC4 has a broad substrate activity towards aliphatic, heterocyclic, and aromatic nitriles, as well as arylacetonitriles. Iminodiacetonitrile, an aliphatic nitrile, was the optimal substrate but comparable activities were also observed with phenylacetonitrile and indole-3-acetonitrile. BGC4-expressing cells degraded industrial nitriles, such as acrylonitrile, adiponitrile, benzonitrile, mandelonitrile, and 3-cyanopyridine, showing good tolerance and conversion rates. CONCLUSION: BGC4 nitrilase has wide-spectrum substrate specificity and is suitable for efficient biodegradation of toxic nitriles.
OBJECTIVE: To investigate the biodegradation of nitriles via the nitrilase-mediated pathway. RESULTS: A novel nitrilase, BGC4, was identified from proteobacteria Paraburkholderia graminis CD41M and its potential for use in biodegradation of toxic nitriles in industrial effluents was studied. BGC4 was overexpressed in Escherichia coli BL21 (DE3), the recombinant protein was purified and its enzymatic properties analysed. Maximum activity of BGC4 nitrilase was at 30 °C and pH 7.6. BGC4 has a broad substrate activity towards aliphatic, heterocyclic, and aromatic nitriles, as well as arylacetonitriles. Iminodiacetonitrile, an aliphatic nitrile, was the optimal substrate but comparable activities were also observed with phenylacetonitrile and indole-3-acetonitrile. BGC4-expressing cells degraded industrial nitriles, such as acrylonitrile, adiponitrile, benzonitrile, mandelonitrile, and 3-cyanopyridine, showing good tolerance and conversion rates. CONCLUSION:BGC4 nitrilase has wide-spectrum substrate specificity and is suitable for efficient biodegradation of toxic nitriles.