title: Identification and characterization of a novel N-acyl-homoserine lactonase gene in Sphingomonas ursincola isolated from industrial cooling water systems.
abstract: Biofilm formation by bacteria is one of the main causes of fouling in industrial cooling water systems. In many gram-negative bacteria, biofilm formation is regulated by N-acyl-homoserine lactone (AHL)-mediated quorum sensing. In this study, we isolated three AHL-degrading bacteria from cooling water systems and identified them as Sphingomonas ursincola. The draft genome sequence of S. ursincola A1 revealed the presence of an AHL-degrading gene homolog, designated qsdS. The qsdS region was also amplified by PCR from the genomes of the other two S. ursincola strains, SF1 and SF8. Escherichia coli DH5α harboring a QsdS-expressing plasmid showed high degradative activity against AHLs with short and 3-oxo-substituted acyl chains. High-performance liquid chromatography analysis revealed that QsdS is an AHL lactonase, an enzyme that catalyzes AHL ring opening. Furthermore, heterologous expression of QsdS in Pseudomonas aeruginosa PAO1 resulted in degradation of endogenous AHLs and interfered with the quorum-sensing-regulated phenotype.
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan. Electronic address: morohosi@cc.utsunomiya-u.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Morohoshi
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan.
authors.forename: Niina
authors.initials: N
authors.lastname: Sato
authors.affiliation: Kurita Global Technology Center, Kurita Water Industries Ltd., 1-1 Kawada, Nogi-machi, Shimotsuga-gun, Tochigi 329-0105, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Iizumi
authors.affiliation: Kurita Global Technology Center, Kurita Water Industries Ltd., 1-1 Kawada, Nogi-machi, Shimotsuga-gun, Tochigi 329-0105, Japan.
authors.forename: Airi
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D054742:Acyl-Butyrolactones / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007221:Industry; D016133:Polymerase Chain Reaction; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism; D053038:Quorum Sensing; D020578:Sphingomonas / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D054742:Acyl-Butyrolactones; D002265:Carboxylic Ester Hydrolases
keywords: Cooling water system; Lactonase; N-Acyl-homoserine lactone; Quorum sensing; Sphingomonas