Pseudomonas sesami sp nov., a plant growth-promoting Gammaproteobacteria isolated from the rhizosphere of Sesamum indicum L.

摘要

A novel Gram-stain negative, aerobic, motile, rod-shaped bacterium was isolated from Sesame (Sesamum indicum L.) rhizosphere soil. Based on the 16S rRNA gene similarity value (99.4-98.6%) obtained with phylogenetically closely related strains and through analyses of their house keeping genes (atpD, infB and rpoB), the strain SI-P133(T) was delineated among the species of the genus Pseudomonas and was subjected to polyphasic taxonomic analysis. It was a chemoorganotroph which grew at wide range of temperature (4-45 A degrees C), pH (5.5-9.5) and NaCl concentrations (0-7% (w/v). DNA-DNA hybridization values with closely related type strains DSM 9751(T), DSM 19095(T), DSM 21509(T), ICMP 9151(T) and DSM 6929(T) ranged from 23.1 to 44.2%. The most abundant fatty acids were C-16:0, C-10:0 3-OH, summed feature 3 (comprising C-16:1 omega 7c and/or C-16:1 omega 6c), C-17:0 cyclo and C-12:0 3-OH. The major isoprenoid quinone system was ubiquinone 9 (Q-9) and the G+C content was 61.3 mol%. The major polar lipids of the strain SI-P133(T) were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. With regard to prospective use in agriculture, plant growth-promoting properties of the strain were tested and plant growth-promotion was demonstrated under in vitro conditions. Based on the various polyphasic taxonomic traits analysed, the strain SI-P-133(T) was novel and placed within the genus Pseudomonas. Hence we propose a novel species named Pseudomonas sesami sp. nov., for which the type strain is SI-P133(T) (=NCIMB 14519(T) = KCTC 22518(T)).