Abstract:
Three strains, namely L3B39T, L3D16, and L1E9, were obtained while studying the cultivable rhizosphere bacteria of saline tolerant pokkali rice, at Kerala, India. The novel strains were negative for many plant growth promoting plate assays such as phytohormone and siderophore production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase and growth in nitrogen free agar medium but found to utilize malic acid, citrate, D-glucose, L-arabinose, and D-maltose, important components of the plant root exudates, indicating that they are normal plant rhizosphere residents without yet known benefits to the plant. The 16S rRNA gene analysis placed these strains in the genus Vogesella, forming a separate branch independent of the previously described type strains of this genus in all tree making algorithms applied. Vogesella perlucida DS-28T was the type strain with highest 16S rRNA sequence similarity (97.59%). DNA-DNA hybridization values among these novel strains were above 85% andthat with Vogesella perlucida LMG 24214T was below 50%. Phenotypically, the novel strains can be differentiated from Vogesella perlucida LMG 24214T by many characters such as NaCl tolerance, growth temperature, and utilization of L-arabinose, D-maltose, and citrate. These novel strains contain C16:1ω6c/C16:1ω7c and C16:0 as major fatty acids, ubiquinone Q-8 as the major respiratory quinone, and phosphatidylethanolamine and phosphatidylglycerol as major polar lipids. Based on the results obtained from the polyphasic taxonomic approach we conclude that the strains belong to a novel Vogesella species for which the name Vogesella oryzae sp.nov. is proposed. The type strain is L3B39T (= LMG 28272T = DSM 28780T).
