Prof. ZHANG Huiwen, Prof. XU Mingkai and doctoral research student YU Zhixiong are researchers from the Microbial Resources and Ecology Group of the Institute of Applied Ecology (IAE) of the Chinese Academy of Sciences (CAS), who recently performed a whole-genome sequencing on Chenggangzhangella methanolivorans CHL1, a CE-degrading strain first obtained by the same group of researchers.

Prof. ZHANG and her colleagues determined the complete genome structure of strain CHL1. By conducting the gene knockout and gene complementation experiments, they confirmed that three genes, sulE, pnbA, and gst, were related to the enzymes responsible for the biodegradation of CE.

By cloning and expressing the three genes in Escherichia coli system, the researchers identified that the glutathione-S-transferase-encoding gene, gst, could catalyze the cleavage of the sulfonylurea bridge of CE, while that the two esterase-encoding genes, sulE and pnbA, could de-esterify CE.

This study revealed molecular and enzymatic mechanisms of the degradation of CE by strain CHL1, providing an approach to produce new "engineered bacteria" for remediating the environments contaminated by sulfonylurea herbicides.

"The known genes and enzymes involved in the degradation of sulfonylurea herbicides are still limited, and they need to be explored further," the researchers said.

This study was published in Microbiology Spectrum, entitled "Whole Genome Sequencing of a Chlorimuron-Ethyl-Degrading Strain: Chenggangzhangella methanolivorans CHL1 and Its Degrading Enzymes," and it was funded by the Natural Science Foundation of China, the Strategic Priority Research Program (on Black Soil Research) of the Chinese Academy of Sciences, the Major S&T Achievement Transformation Project of Shenyang Municipal Science and Technology Bureau, and the Doctoral Start-up Fund of Liaoning Province.

Contact 

YUE Qian

Institute of Applied Ecology, Chinese Academy of Sciences 

Tel: 86-24-83970324 

E-mail: yueqian@iae.ac.cn  

Web: http://english.iae.cas.cn