Pseudomonas lyxosi sp. nov., Pseudomonas arabinosi sp. nov. and Pseudomonas frigoris sp. nov., isolated from glaciers

Three Gram-stain-negative, rod-shaped, motile bacterial strains, each with a single polar flagellum, designated LB3P38^T, LT1P18^T and ZB1P45^T, were isolated from glacier samples on the Tibetan Plateau, P.R. China. These strains grew at temperatures ranging from -2 to 32 °C (optimum 25-30 °C) and at pH values of 5.0-11.0 (optimum pH 7.0). The similarities of 16S rRNA gene sequences among these strains ranged from 99.67% to 99.93%. Phylogenetic analysis based on 16S rRNA gene sequences confirmed their affiliation with the genus <i>Pseudomonas</i>. Phylogenomic analysis positioned these strains in close relation to <i>Pseudomonas svalbardensis</i> PMCC 200367^T and <i>Pseudomonas frederiksbergensis</i> LMG 19851^T. Average nucleotide identity values and digital DNA-DNA hybridization values between these strains and other type strains of the genus <i>Pseudomonas</i> were below 94.6% and 63.4%, respectively. The predominant fatty acids identified in these strains were C_16:0, C_17:0 cyclo and summed feature 3 (C_16:1 <i>ω7</i>c and/or C_16:1 <i>ω6</i>c). Based on the combined phenotypic and phylogenetic evidence, each strain is proposed to represent a novel species within the genus <i>Pseudomonas</i>, with the names <i>Pseudomonas lyxosi</i> sp. nov. (type strain=LB3 P38^T=CGMCC 1.11284^T=JCM 37126^T), <i>Pseudomonas arabinosi</i> sp. nov. (type strain=LT1 P18^T=CGMCC 1.11310^T=JCM 37131^T) and <i>Pseudomonas frigoris</i> sp. nov. (type strain=ZB1 P45^T=CGMCC 1.23235^T=JCM 37141^T) proposed.