Pseudomonas seleniipraecipitatus sp. nov.: a selenite reducing γ-proteobacteria isolated from soil.

ABSTRACT

A Gram-negative, yellow pigmented bacterium designated strain CA5(T) that reduced selenite to elemental red selenium was isolated from soil. 16S rRNA gene sequence alignment identified the isolate as a novel Pseudomonas species with P. argentinensis, P. flavescens, and P. straminea as its closest relatives. Sequence alignments show that the 16S rRNA gene of strain CA5(T) differed from that of P. argentinensis, P. flavescens, and P. straminea by 1.3, 1.5, and 1.7%, respectively. The G+C content was 62.8 mol%, similar to the 62.7-63 mol% reported for P. flavescens but slightly higher than the 62.5-62.6 mol% of P. straminea and significantly higher than the 57.5-58.0 mol% of P. argentinensis. The major cellular fatty acids present in the CA5(T) strain were C181 ω7c (41.1%), C161 ω6c and C161 ω7c (25.7%), C161 (12.0%), C120 (8.0%), C120 3-OH (4.4%), and C100 3-OH (2.9%). The cellular fatty acid profile, GC content, phenotypic properties, and biochemical characteristics were consistent with its placement within the genus Pseudomonas. The name P. seleniipraecipitatus is proposed for these bacteria.