Molecular cloning, purification and biochemical characterization of a novel pyrethroid-hydrolyzing carboxylesterase gene from Ochrobactrum anthropi YZ-1

作者：Zhai Yi; Li Kang; Song Jinlong; Shi Yanhua; Yan Yanchun^*

来源：Journal of Hazardous Materials, 2012, 221: 206-212.

DOI：10.1016/j.jhazmat.2012.04.031

• Pyrethroids
• Biodegradation
• Carboxylesterase
• Genomic library

Strain YZ-1 was isolated from activated sludge and identified as Ochrobactrum anthropi. This strain was capable of degrading pyrethroids pesticides, suggesting the presence of degrading enzymes. In the present study, a novel esterase gene pytZ was cloned from the genomic library of YZ-1 successfully. The pytZ contained an open reading frame of 606 bp encoding a pyrethroid-hydrolyzing carboxylesterase. Deduced amino acid sequence showed moderate identities (39-59%) with most homologous carboxylesterase, except a putative carboxylesterase from O. anthropi ATCC 49188 with the highest identity of 85%. Phylogenetic analysis revealed that PytZ belonged to esterase VI family. The gene pytZ showed no any sequence similarity with reported pyrethroid-hydrolyzing genes and was a new pyrethroid-degrading gene. PytZ was expressed in Escherichia coil BL21 (DE3) and purified using Ni-NTA Fast Start. PytZ was able to degrade various pyrethroids. The optimal temperature and pH were 35 degrees C and 7.5. This enzyme was very stable over a wide range of temperature and pH. No cofactors were required for enzyme activity. Broad substrate specificity, high enzyme activity, and the favorable stability make the PytZ a potential candidate for the detoxification of pyrethroid residues in biotechnological application.

• 出版日期2012-6-30
• 单位中国农业科学院