title: A key esterase required for the mineralization of quizalofop-p-ethyl by a natural consortium of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9.
abstract: A natural consortium, named L1, of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9 was obtained from quizalofop-p-ethyl (QE) polluted soil. The consortium was able to use QE as a sole carbon source for growth and degraded 100mgL-1of QE in 60h. Strain JT-3 initiated the catabolism of QE to quizalofop acid (QA), which was used by strain JT-9 as carbon source for growth and to simultaneously feed strain JT-3. A novel esterase EstS-JT, which was responsible for the transformation of QE to QA and essential for the mineralization of QE by the consortium, was cloned from strain JT-3. EstS-JT showed low amino acid identity to other reported esterases from esterase family VIII and represents a new member of this family. The deduced amino acid sequence contained the esterase family VIII conserved motifs S-X-X-K, YSV and WAG. The purified recombinant EstS-JT displayed maximal esterase activity at 35°C and pH 7.5. An inhibitor assay, site-directed mutagenesis and 3D modeling analysis revealed that S64, K67and Y175were essential for catalysis and probably comprised the catalytic center of EstS-JT. Additionally, EstS-JT had broad substrate specificity and was capable of hydrolyzing p-nitrophenyl esters (C2-C8) and various AOPP herbicides.
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Mengya
authors.initials: M
authors.lastname: Li
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China. Electronic address: guangliwang@aliyun.com.
authors.forename: Guangli
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Dayong
authors.initials: D
authors.lastname: Xu
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
authors.forename: Minghua
authors.initials: M
authors.lastname: Xiong
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002384:Catalysis; D003001:Cloning, Molecular; D004950:Esterases / Q000737:chemistry* / Q000235:genetics; D006540:Herbicides / Q000032:analysis; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D011422:Propionates / Q000737:chemistry*; D020560:Proteobacteria / Q000201:enzymology* / Q000235:genetics; D011810:Quinoxalines / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D012240:Rhodococcus / Q000201:enzymology* / Q000235:genetics; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D006540:Herbicides; D011422:Propionates; D011810:Quinoxalines; D011994:Recombinant Proteins; D012989:Soil Pollutants; C064835:quizalofop-ethyl; D004950:Esterases
keywords: Consortium; Esterase; Mineralization; Quizalofop-P-ethyl