Pseudomonas nitritireducens sp. nov., a nitrite reduction bacterium isolated from wheat soil.

A Gram-negative, non-mobile, polar single flagellum, rod-shaped bacterium WZBFD3-5A2(T) was isolated from a wheat soil subjected to herbicides for several years. Cells of strain WZBFD3-5A2(T) grow optimally on Luria-Bertani agar medium at 30 °C in the presence of 0-4.0 % (w/v) NaCl and pH 8.0. 16S rRNA gene sequence analysis revealed that strain WZBFD3-5A2(T) belongs to the genus Pseudomonas. Physiological and biochemical tests supported the phylogenetic affiliation. Strain WZBFD3-5A2(T) is closely related to Pseudomonas nitroreducens IAM1439(T), sharing 99.7 % sequence similarity. DNA-DNA hybridization experiments between the two strains showed only moderate reassociation similarity (33.92 ± 1.0 %). The DNA G+C content is 62.0 mol%. The predominant respiratory quinine is Q-9. The major cellular fatty acids present are C(16:0) (28.55 %), C(16:1ω6c) or C(16:1ω7c) (20.94 %), C(18:1ω7c) (17.21 %) and C(18:0) (13.73 %). The isolate is distinguishable from other related members of the genus Pseudomonas on the basis of phenotypic and biochemical characteristics. From the genotypic, chemotaxonomic and phenotypic data, it is evident that strain WZBFD3-5A2(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas nitritereducens sp. nov. is proposed. The type strain is WZBFD3-5A2(T) (=CGMCC 1.10702(T) = LMG 25966(T)).