Pseudacidovorax austerolens sp. nov., a nifH bacterium isolated from Himalayan valley soil, India

Abstract

Gram-negative, rod-shaped bacterial strain ptl-2T, was isolated from soil of the Himalayan valley, India. The bacterial strain ptl-2T has been characterized using a polyphasic taxonomic approach including morphological characterization, fatty acid analysis, biochemical tests, 16S rRNA and nifH gene sequence analysis. 16S rRNA gene sequence analysis showed that the strain ptl-2T belonged to the genus Pseudacidovorax and is closely related to Pseudacidovorax intermedius (99.3 % similarity). It showed <97 % similarity to species of the genera Acidovorax, Alicycliphilus, Xylophilus, Giesbergeria and Simplicispira. The generic assignment has been confirmed on the basis of chemotaxonomic data, which revealed the fatty acid profile, characteristic of the genus Pseudacidovorax, consisting of C16:0 (21.78) and C18:1w7c (19.78) as major fatty acids. Phylogenetic, chemotaxonomic and phenotypic analysis based on signature sequences, DNA-DNA hybridization and physiological characterizations, confirms that strain ptl-2T represents a different species of the genus Pseudacidovorax for which the name Pseudacidovorax austerolens sp. nov. is proposed. The type strain ptl-2T (= CCUG 58759T, = DSM 24877T) has been submitted to two culture collection centres. GenBank accession numbers for the 16S rRNA and nifH sequence of strain Pseudacidovorax austerolens ptl-2T are FJ581042 and GQ249664, respectively.