Bacillus zanthoxyli sp. nov., a novel nematicidal bacterium isolated from Chinese red pepper (Zanthoxylum bungeanum Maxim) leaves in China.

Abstract

A novel strain, 1433T, was isolated from leaves of Chinese red pepper (Huajiao, Zanthoxylum bungeanum Maxim) collected from Gansu province in northwestern China, and was characterised by a polyphasic approach. Cells of strain 1433T were observed to be Gram-stain positive, aerobic, asporogenous, rod shaped, motile and to have peritrichous flagella. The strain was observed to grow at a range of temperatures and pH, 4-45°C (optimum 28-32°C) and 6.0-10.0 (optimum pH 6.0-7.0), respectively. Growth was found to occur in the presence of 0-7% (w/v) NaCl [optimum 0-3% (w/v)]. The G+C content of the genomic DNA was determined to be 41.9mol% and the cell wall peptidoglycan found to contain meso-diaminopimelic acid. The predominant menaquinone was identified as MK-7 and the major polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified polar lipid and three unidentified phospholipids. The major cellular fatty acids were identified as iso-C15:0 (31.6%), anteiso-C15:0 (26.9%) and iso-C14:0 (17.1%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1433T is a member of the genus Bacillus and is closely related to Bacillus aryabhattai DSM 21047T (99.4% sequence similarity) and Bacillus megaterium DSM 32T (99.2%). DNA-DNA relatedness of the novel strain 1433T with B. aryabhattai DSM 21047T and B. megaterium DSM 32T was 33.8±2.8% and 28.9±3.4%, respectively. On the basis of the polyphasic evidence presented, strain 1433T is considered to represent a novel species of the genus Bacillus, for which we propose the name Bacillus zanthoxyli sp. nov. The type strain is 1433T (=CCTCC AB 2016326T=KCTC33730T).