title: Novel hydrolytic de-methylthiolation of the s-triazine herbicide prometryn by Leucobacter sp. JW-1.
abstract: s-Triazine herbicides have been widely used in recent decades and caused serious concern over contamination of groundwater, surface water and soil. A novel bacterial strain JW-1 was isolated from activated sludge and identified as Leucobacter sp. based on comparative morphology, physiological characteristics and comparison of the 16S rDNA gene sequence. JW-1 was capable of using methylthio-s-triazine prometryn as a sole source of carbon and energy in pure culture. Favorable conditions for prometryn degradation were found at pH7.0-9.0 and temperature of 37-42°C. The degradation half-life of prometryn at 50mgL-1was remarkably as short as 1.1h, and increased to 6.0h when the initial concentration increased to 400mgL-1. The strain JW-1 could degrade 100% of ametryn, 99% of simetryn, 41% of propazine, 43% of atrazine, 28% of simazine, 12% of terbutylhylazine, 10% of prometon and 13% of atraton at 50mgL-1of each herbicide in 2days. Prometryn was converted to 2-hydroxypropazine and methanthiol via a novel hydrolysis pathway. 2-Hydroxypropazine was then transformed to N-isopropylammelide and the final product cyanuric acid via two sequential deamination reactions. In addition to biodegradation by Leucobacter sp. JW-1, the hydrolytic de-methylthiolation would be valuable in biocatalysis.
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Rimao
authors.initials: R
authors.lastname: Hua
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Pei
authors.initials: P
authors.lastname: Lv
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China.
authors.forename: Haiqun
authors.initials: H
authors.lastname: Cao
authors.affiliation: College of Resources and Environment, Anhui Agricultural University, Key Laboratory of Agri-food Safety of Anhui Province, Hefei 230036, PR China. Electronic address: wxwahau@ahau.edu.cn.
authors.forename: Xiangwei
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 957822, USA.
authors.forename: Qing X
authors.initials: QX
authors.lastname: Li
mesh_terms: D039903:Actinobacteria / Q000502:physiology*; D001673:Biodegradation, Environmental; D006540:Herbicides / Q000378:metabolism*; D014227:Triazines / Q000378:metabolism*
chemical_list: D006540:Herbicides; D014227:Triazines
keywords: Biodegradation; De-methylthiolation; Leucobacter sp.; Prometryn; Triazine herbicide