Echinicola soli sp. nov., isolated from alkaline saline soil

Abstract

Strains of <i>Echinicola</i>, thought to play vital roles in the environment for their high enzyme production capacity during decomposition of polysaccharides, are ubiquitous in hypersaline environments. A Gram-negative, non-spore forming, gliding, aerobic bacterial strain, designated LN3S3^T, was isolated from alkaline saline soil sampled in Tumd Right Banner, Inner Mongolia, northern PR China. Strain LN3S3^T grew at 10-40 °C (optimum, 30 °C), pH 5.0-9.0 (optimum, pH 8.0) and with 0-12.5 % NaCl (optimum, 2.0 %). A phylogenetic tree based on the 16S rRNA gene sequences showed that strain LN3S3^T clustered with <i>Echinicola rosea</i> JL3085^T and <i>Echinicola strongylocentroti</i> MEBiC08714^T, sharing 97.0, 96.7 and <96.50 % of 16S rRNA gene sequence similarities to <i>E. rosea</i> JL3085^T, <i>E. strongylocentroti</i> MEBiC08714^T and all other type strains. MK-7 was the major respiratory quinone, while phosphatidylethanolamine, two unidentified phospholipids, an unidentified aminophospholipid, an unidentified lipid and two unidentified aminolipids were the major polar lipids. Its major cellular fatty acids were iso-C_{15 : 0}, anteiso-C_{15 : 0} and summed feature 3 (C_{16 : 1} <i> </i>ω7<i>c</i> and/or C_{16 : 1} <i> </i>ω6<i>c</i>). The genome consisted of a circular 5 550 304 bp long chromosome with a DNA G<i>+</i>C content of 44.0 mol%. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values of strain LN3S3^T to <i>E. rosea</i> JL3085^T and <i>E. strongylocentroti</i> MEBiC08714^T were 82.5 and 81.5 %, 87.5 and 86.0 %, and 39.1 and 35.1 %, respectively. Based on physiological, genotypic and phylogenetic analyses, strain LN3S3^T could be discriminated from its phylogenetic relatives. <i>Echinicola soli</i> sp. nov. is therefore proposed with strain LN3S3^T (=CGMCC 1.17081^T=KCTC 72458^T) as the type strain.