Ochrobactrum oryzae sp. nov., an endophytic bacterial species isolated from deep-water rice in India.

A non-pigmented, motile, Gram-negative bacterium designated MTCC 4195(T) was isolated from surface-sterilized seeds and plant tissue from deep-water rice (Oryza sativa) cultivated in Suraha Tal Lake in northern India. This isolate was shown to reinfect and colonize deep-water rice endophytically. The highest level of 16S rRNA sequence similarity (96.8 %) to strain MTCC 4195(T) was shown by Ochrobactrum gallinifaecis DSM 15295(T). Strain MTCC 4195(T) utilized gamma-hydroxybutyric acid, adonitol, d-glucosaminic acid and arabinose as carbon sources, but failed to use gentiobiose or citrate. The cell-wall fatty acids of strain MTCC 4195(T) were characterized by the presence of a relatively large proportion of C(18 : 1)omega7c and a relative small proportion of C(16 : 0) in comparison with Ochrobactrum species. DNA-DNA relatedness studies showed less than 52 % binding with the DNAs of type strains of other species of the genus Ochrobactrum. On the basis of phenotypic and genotypic characteristics and the results of 16S rRNA gene sequence analysis, the novel species Ochrobactrum oryzae sp. nov. is proposed, with MTCC 4195(T) (=DSM 17471(T)) as the type strain.