Simplicispira soli sp. nov., a betaproteobacterium isolated from stream bank soil.

Abstract

Two strains of soil bacteria, designated CA-16T and CA-161, were isolated from a sample of stream bank soil near Kyonggi University. Cells were strictly aerobic, Gram-stain-negative, catalase-negative, oxidase-positive, motile, non-spore-forming and rod-shaped. Colonies on tryptone soya agar were brownish cream in colour. Tyrosine, Tween 60 and Tween 40 were hydrolysed. The indole test was positive. Malic acid, lactic acid and valeric acid were assimilated. Phylogenetic analysis based on their 16S rRNA gene sequences revealed that strains CA-16T and CA-161 formed a lineage within the family Comamonadaceae of the class Betaproteobacteria that were distinct from various species of the genus Simplicispira. Strain CA-16T was most closely related to Simplicispira metamorpha DSM 1837T (97.86 % sequence similarity), Simplicispira limi EMB325T (97.72 %), Simplicispira psychrophila DSM 11588T (96.83 %) and Simplicispira piscis RSG39T (96.71 %). Both strains contained Q-8 as the major isoprenoid quinone. The major polar lipids of the strains were phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. The major cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1 ω7c-11methyl, C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C12 : 0. The DNA G+C contents of the strains were 63.9-64.4 mol%. DNA-DNA hybridization similarities between strain CA-16T and other closest members of the genus Simplicispira ranged from 16 % to 24 %. On the basis of phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, strains CA-16T and CA-161 represent a single novel species of the genus Simplicispira, for which the name Simplicispirasoli sp. nov. is proposed. The type strain is CA-16T (=KEMB 9005-529T=KACC 19107T=NBRC 112689T).