Degradation of acetochlor by consortium of two bacterial strains and cloning of a novel amidase gene involved in acetochlor-degrading pathway.
Two bacterial strains Sphingobium quisquiliarum DC-2 and Sphingobium baderi DE-13 were isolated from activated sludge. Acetochlor was transformed by S. quisquiliarum DC-2 to a transitory intermediate 2-chloro-N-(2-methyl-6-ethylphenyl)acetamide (CMEPA), which was further transformed to 2-methyl-6-ethylaniline (MEA), and MEA could not be degraded by strain DC-2. S. baderi DE-13, incapable of degrading acetochlor, showed capability of degrading MEA to an intermediate 2-methyl-6-ethylaminophenol (MEAOH). MEAOH was further transformed to 2-methyl-6-ethylbenzoquinoneimine (MEBQI), which was mineralized by strain DE-13. A gene, cmeH, encoding an amidase that catalyzed the amide bond cleavage of CMEPA was cloned from strain DC-2. CmeH was expressed in Escherichia coli BL21 and homogenously purified using Ni-nitrilotriacetic acid affinity. CmeH efficiently hydrolyzed CMEPA and other important herbicide, such as propanil, fenoxaprop-p-ethyl and clodinafop-propargyl.
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Yi
Y
Li
Qing
Q
Chen
Cheng-Hong
CH
Wang
Shu
S
Cai
Jian
J
He
Xing
X
Huang
Shun-Peng
SP
Li
D000581:Amidohydrolases / Q000235:genetics*; D000814:Aniline Compounds / Q000378:metabolism; D001673:Biodegradation, Environmental; D003001:Cloning, Molecular; D005798:Genes, Bacterial / Q000235:genetics*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D059013:Microbial Consortia / Q000235:genetics*; D017422:Sequence Analysis, DNA; D042301:Sphingomonadaceae / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D014052:Toluidines / Q000378:metabolism*
D000814:Aniline Compounds; D014052:Toluidines; C043377:acetochlor; D000581:Amidohydrolases; C019665:amidase; C023650:aniline
Acetochlor; Amidase gene; Biodegradation; Metabolic pathway