title: Characterization of a phenazine-producing strain Pseudomonas chlororaphis GP72 with broad-spectrum antifungal activity from green pepper rhizosphere.
abstract: A new Pseudomonas strain, designated GP72, was isolated from green pepper rhizosphere and identified as a member of species Pseudomonas chlororaphis based on morphology; conventional biochemical and physiologic tests; Biolog GN system (Biolog Inc., Hayward, CA); and 16S rDNA sequence analysis. The secondary metabolites produced by this strain have shown broad-spectrum antifungal activity against various phytopathogens of agricultural importance in vitro. Two main antifungal substances produced by this strain proved to be phenazine-1-carboxylic acid and 2-hydroxyphenazine with further purification and structure elucidation based on ultraviolet-absorbent spectrum scanning, atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) spectrum, and (1)H,(13)C nuclear magnetic resonance spectrums. Strain GP72 could produce quorum-sensing signaling molecules of N-butanoyl-L-homoserine lactone and N-hexanoyl-L-homoserine lactone, which were found to accumulate with different quantities in King's medium B and pigment producing medium, respectively.
authors.affiliation: Key Laboratory of Microbial Metabolism, Ministry of Education and College of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai, 200240, PRC.
authors.forename: Haiming
authors.initials: H
authors.lastname: Liu
authors.forename: Yanjing
authors.initials: Y
authors.lastname: He
authors.forename: Haixia
authors.initials: H
authors.lastname: Jiang
authors.forename: Huasong
authors.initials: H
authors.lastname: Peng
authors.forename: Xianqing
authors.initials: X
authors.lastname: Huang
authors.forename: Xuehong
authors.initials: X
authors.lastname: Zhang
authors.forename: Linda S
authors.initials: LS
authors.lastname: Thomashow
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism*; D002212:Capsicum / Q000382:microbiology*; D002855:Chromatography, Thin Layer; D004275:DNA, Ribosomal / Q000235:genetics; D006714:Homoserine / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D010619:Phenazines / Q000378:metabolism*; D010802:Phylogeny; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D000935:Antifungal Agents; D004275:DNA, Ribosomal; D010619:Phenazines; D012336:RNA, Ribosomal, 16S; C037165:1-phenazinecarboxylic acid; C088013:2-hydroxyphenazine; D006714:Homoserine