title: Increasing viscosity and yields of bacterial exopolysaccharides by repeatedly exposing strains to ampicillin.
abstract: A universal method to enhance productivity and viscosity of bacterial exopolysaccharides was developed. The technique was based on the principle that ampicillin can inhibit the biosynthesis of peptidoglycan, which shares a common synthetic pathway with that of bacterial exopolysaccharides. Serial passages of three typical representatives of bacterial EPS-producing strains, namely Sphingomonas elodea, Xanthomonas campestris, and Paenibacillus elgii, were subjected to ampicillin, which was used as a stressor and a mutagen. These mutant strains are advantageous over other strains because of two major factors. First, all of the resulting strains were almost mutants with increase in EPS productivity and viscosity. Second, isolated serial strains showed different levels of increase in EPS production and viscosity to satisfy the different requirements of practical applications. No differences were observed in the monosaccharide composition produced by the mutant and parent strains; however, high-viscosity mutant strains exhibited higher molecular weights. The results confirmed that the developed method is a controlled universal one that can improve exopolysaccharides productivity and viscosity.
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Ou
authors.initials: O
authors.lastname: Li
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Ao
authors.initials: A
authors.lastname: Liu
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Cui
authors.initials: C
authors.lastname: Lu
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Dao-qiong
authors.initials: DQ
authors.lastname: Zheng
authors.affiliation: College of Life Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, PR China.
authors.forename: Chao-dong
authors.initials: CD
authors.lastname: Qian
authors.affiliation: Institute of Marine Biology & Natural Products, Department of Ocean Science and Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Pin-Mei
authors.initials: PM
authors.lastname: Wang
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China.
authors.forename: Xin-Hang
authors.initials: XH
authors.lastname: Jiang
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, PR China. Electronic address: mblab@163.com.
authors.forename: Xue-Chang
authors.initials: XC
authors.lastname: Wu
mesh_terms: D000667:Ampicillin / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000378:metabolism; D002240:Carbohydrate Sequence; D007218:Industrial Microbiology; D008969:Molecular Sequence Data; D009153:Mutagens / Q000378:metabolism*; D056507:Paenibacillus / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000378:metabolism*; D020578:Sphingomonas / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014783:Viscosity; D016959:Xanthomonas campestris / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D009153:Mutagens; D011135:Polysaccharides, Bacterial; C048288:gellan gum; D000667:Ampicillin; C002563:xanthan gum
keywords: Ampicillin; Exopolysaccharide; Gellan gum; Paenibacillus elgii; Xanthan gum