title: Inhibition of biofilm in Bacillus amyloliquefaciens Q-426 by diketopiperazines.
abstract: Biofilm formation can make significant effects on bacteria habits and biological functions. In this study, diketopiperazines (DKPs) produced by strain of Bacillus amyloliquefaciens Q-426 was found to inhibit biofilm formed in the gas-liquid interface. Four kinds of DKPs were extracted from B. amyloliquefaciens Q-426, and we found that 0.04 mg ml(-1) DKPs could obviously inhibit the biofilm formation of the strain. DKPs produced by B. amyloliquefaciens Q-426 made a reduction on extracellular polymeric substance (EPS) components, polysaccharides, proteins, DNAs, etc. Real-time PCR was performed to determine that whether DKPs could make an obvious effect on the expression level for genes related to biofilm formation in the strain. The relative expression level of genes tasA, epsH, epsG and remB which related to proteins, extracellular matrix, and polysaccharides, were downregulated with 0.04 mg ml(-1) DKPs, while the expression level of nuclease gene nuc was significantly upregulated. The quantitative results of the mRNA expression level for these genes concerted with the quantitative results on EPS levels. All of the experimental results ultimately indicated that DKPs could inhibit the biofilm formation of the strain B. amyloliquefaciens Q-426.
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China. jhwang@yic.ac.cn.|Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. jhwang@yic.ac.cn.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
authors.affiliation: Key Laboratory of Coastal Biology and Biological Resources Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
authors.forename: Cui-Yun
authors.initials: CY
authors.lastname: Yang
authors.affiliation: Key Laboratory of Coastal Biology and Biological Resources Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
authors.forename: Sheng-Tao
authors.initials: ST
authors.lastname: Fang
authors.affiliation: Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lu
authors.affiliation: Life Science College, Dalian Nationalities University, Dalian, 116600, China. mikyeken@dlnu.edu.cn.
authors.forename: Chun-Shan
authors.initials: CS
authors.lastname: Quan
mesh_terms: D000069977:Bacillus amyloliquefaciens / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms / Q000187:drug effects; D054659:Diketopiperazines / Q000494:pharmacology*; D015536:Down-Regulation; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D054659:Diketopiperazines
keywords: Bacillus amyloliquefaciens Q-426; Biofilm; Diketopiperazines (DKPs); Extracellular polymeric substance (EPS); Real-time PCR