title: Loss of GltB Inhibits Biofilm Formation and Biocontrol Efficiency of Bacillus subtilis Bs916 by Altering the Production of γ-Polyglutamate and Three Lipopeptides.
abstract: OBJECTIVE
  This study examined the contribution of GltB on biofilm formation and biocontrol efficiency of B. subtilis Bs916.
  
  
  RESULTS
  The gltB gene was identified through a biofilm phenotype screen and a bioinformatics analysis of serious biofilm formation defects, and then a gltB single knockout mutant was constructed using homologous recombination. This mutant demonstrated severe deficits in biofilm formation and colonisation along with significantly altered production ofγ-polyglutamate (γ-PGA) and three lipopeptide antibiotics (LPs) as measured by a transcriptional analysis of both the wild type B. subtilis Bs916 and the gltB mutant. Consequently, the mutant strain retained almost no antifungal activity against Rhizoctonia solani and exhibited decreased biocontrol efficiency against rice sheath blight. Very few gltB mutant cells colonised the rice stem, and they exhibited no significant nutrient chemotaxis compared to the wild type B. subtilis Bs916. The mechanism underlying these deficits in the gltB mutant appears to be decreased significantly in production of γ-PGA and a reduction in the production of both bacillomycin L and fengycin. Biofilm restoration of gltB mutant by additionγ-PGA in the EM medium demonstrated that biofilm formation was able to restore significantly at 20 g/L.
  
  
  CONCLUSIONS
  GltB regulates biofilm formation by altering the production ofγ-PGA, the LPs bacillomycin L and fengcin and influences bacterial colonisation on the rice stem, which consequently leads to poor biocontrol efficiency against rice sheath blight.
  
  
  CONCLUSIONS
  This is the first report of a key regulatory protein (GltB) that is involved in biofilm regulation and its regulation mechanism and biocontrol efficiency by B. subtilis.
authors.affiliation: College of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Huafei
authors.identifier: http://orcid.org/0000-0002-8243-8959
authors.initials: H
authors.lastname: Zhou
authors.affiliation: College of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|School of Life Science and Chemical Engineering, Huaiyin Institute of Technology, Huaiyin 223003, China.
authors.forename: Chuping
authors.initials: C
authors.lastname: Luo
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Xianwen
authors.initials: X
authors.lastname: Fang
authors.affiliation: College of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Rongsheng
authors.initials: R
authors.lastname: Zhang
authors.affiliation: College of Plant Protection, Nanjing Agriculture University, Nanjing 210095, China.|Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Chen
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling / Q000379:methods; D055666:Lipopeptides / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation; D012275:Oryza / Q000382:microbiology; D010456:Peptides, Cyclic / Q000378:metabolism / Q000494:pharmacology; D010935:Plant Diseases / Q000517:prevention & control; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides; D010456:Peptides, Cyclic; C511775:poly(gamma-glutamic acid); C049972:fengycin; D011099:Polyglutamic Acid; C015015:bacillomycin L