Abstract

A Gram-negative, aerobic, non spore-forming, non-motile, rod-shaped, yellow pigmented bacterium CP155-2T was isolated from a biological soil crusts sample collected in the Colorado plateau, USA and subjected to polyphasic taxonomic characterization. Strain CP155-2T contained summed feature 3 (C16:1ω5c/C16:1ω7c) and C18:1ω7c as major fatty acids and diphosphatidylglycerol (DPG) along with phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) as major polar lipids. Based on these characteristics CP155-2T was assigned to the genus Pseudomonas. Phylogenetic analysis based on 16S rRNA gene sequence further confirmed the affiliation of CP155-2T to the genus Pseudomonas and showed a 16S rRNA gene sequence similarity of less than 98.7% with already described species of the genus. Pseudomonas luteola, Pseudomonas zeshuii, and Pseudomonas duriflava were identified as the closest species of the genus Pseudomonas with 16S rRNA gene sequence similarities of 98.7%, 98.6%, and 96.9%, respectively. The values for DNA–DNA relatedness between CP155-2T and Pseudomonas luteola and Pseudomonas zeshuii were 23% and 14% respectively a value below the 70% threshold value, indicating that strain CP155-2T belongs to a novel taxon of the genus Pseudomonas lineage. The novel taxon status was strengthened by a number of phenotypic differences wherein CP155-2T was positive for oxidase, negative for gelatin hydrolysis, could utilize D-cellobiose, D-raffinose, L-rhamnose, D-sorbitol but not L-aspartic acid and L-glutamic acid. Based on the collective differences strain CP155-2T exhibited, it was identified as a novel species and the name Pseudomonas asuensis sp. nov. was proposed. The type strain of Pseudomonas asuensis sp. nov. is CP155- 2T (DSM 17866T =ATCC BAA-1264T =JCM13501T =KCTC 32484T).

• Keywords: Pseudomonas asuensis; biological soil crusts; Colorado plateau; United States of America