title: The Addition of N-Hexanoyl-Homoserine Lactone to Improve the Microbial Flocculant Production of Agrobacterium tumefaciens Strain F2, an Exopolysaccharide Bioflocculant-Producing Bacterium.
abstract: In this study, N-hexanoyl-homoserine lactone (C6-HSL), a member of the N-acyl-homoserine lactone class of microbial quorum sensing (QS) signaling molecules, was used to improve microbial flocculant production. After exogenous C6-HSL was added, exopolysaccharide concentration of microbial flocculants was improved by 1.6-fold and flocculation rate of microbial flocculants was increased by 10 %. Fermentation conditions with added C6-HSL were further optimized through response surface methodology. The obtained optimal fermentation conditions were as follows: added C6-HSL concentration of 0.45 μM, fermentation temperature of 30.4 °C, and initial fermentation pH of 7.25. Under these optimal fermentation conditions, the resulting exopolysaccharide concentration was improved by 1.75-fold and flocculation rate was increased by 10 % compared with that of the control group. The yield of microbial flocculants was also improved by 1.75-fold. Results demonstrated that the existence of QS system in Agrobacterium tumefaciens strain F2 played the important roles in the microbial flocculant production.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Jixian
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China. ang.li.harbin@gmail.com.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China. ang.li.harbin@gmail.com.
authors.forename: Ang
authors.initials: A
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China. guohaijuan@163.com.|School of Civil Engineering and Architecture, Taizhou University, Taizhou, 318000, People's Republic of China. guohaijuan@163.com.
authors.forename: Haijuan
authors.initials: H
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Han
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Pi
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Fang
authors.initials: F
authors.lastname: Ma
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D016960:Agrobacterium tumefaciens / Q000187:drug effects / Q000378:metabolism*; D005285:Fermentation; D005427:Flocculation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D053038:Quorum Sensing / Q000187:drug effects*; D013696:Temperature
chemical_list: C104908:N-hexanoyl-L-homoserine lactone; D011135:Polysaccharides, Bacterial; D015107:4-Butyrolactone
keywords: Microbial flocculant; N-acyl-homoserine lactone; Production efficiency; Quorum sensing