title: Newly identified thermostable esterase from Sulfobacillus acidophilus: properties and performance in phthalate ester degradation.
abstract: EstS1, a newly identified thermostable esterase from Sulfobacillus acidophilus DSM10332, was heterologously expressed in Escherichia coli and shown to enzymatically degrade phthalate esters (PAEs) to their corresponding monoalkyl PAEs. The optimal pH and temperature of the esterase were found to be 8.0 and 70°C, respectively. The half-life of EstS1 at 60°C was 15 h, indicating that the enzyme had good thermostability. The specificity constant (kcat/Km) of the enzyme for p-nitrophenyl butyrate was as high as 6,770 mM(-1) s(-1). The potential value of EstS1 was demonstrated by its ability to effectively hydrolyze 35 to 82% of PAEs (10 mM) within 2 min at 37°C, with all substrates being completely degraded within 24 h. At 60°C, the time required for complete hydrolysis of most PAEs was reduced by half. To our knowledge, this enzyme is a new esterase identified from thermophiles that is able to degrade various PAEs at high temperatures.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Qiu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Cheng-Yuan
authors.initials: CY
authors.lastname: Li
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China jianhexu@ecust.edu.cn.
authors.forename: Jian-He
authors.initials: JH
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004950:Esterases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004952:Esters / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010795:Phthalic Acids; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D004952:Esters; D010795:Phthalic Acids; C032279:phthalic acid; D004950:Esterases