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

## TL;DR

This paper describes three new species of Pseudomonas bacteria found in glaciers on the Tibetan Plateau.

## Contribution

The discovery and classification of three novel Pseudomonas species from glacier samples.

## Key findings

- The new species are psychrotolerant, growing at temperatures as low as −2 °C.
- Phylogenomic analysis confirmed their distinct status from other Pseudomonas species.
- Each strain has unique fatty acid profiles and low DNA similarity to other species.

## Abstract

Three Gram-stain-negative, rod-shaped, motile bacterial strains, each with a single polar flagellum, designated LB3P38T, LT1P18T and ZB1P45T, 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 Pseudomonas. Phylogenomic analysis positioned these strains in close relation to Pseudomonas svalbardensis PMCC 200367T and Pseudomonas frederiksbergensis LMG 19851T. Average nucleotide identity values and digital DNA–DNA hybridization values between these strains and other type strains of the genus Pseudomonas were below 94.6% and 63.4%, respectively. The predominant fatty acids identified in these strains were C16:0, C17:0 cyclo and summed feature 3 (C16:1
ω7c and/or C16:1
ω6c). Based on the combined phenotypic and phylogenetic evidence, each strain is proposed to represent a novel species within the genus Pseudomonas, with the names Pseudomonas lyxosi sp. nov. (type strain=LB3 P38T=CGMCC 1.11284T=JCM 37126T), Pseudomonas arabinosi sp. nov. (type strain=LT1 P18T=CGMCC 1.11310T=JCM 37131T) and Pseudomonas frigoris sp. nov. (type strain=ZB1 P45T=CGMCC 1.23235T=JCM 37141T) proposed.