Three strains of Gram-negative, cold-adapted, aerobic bacteria were isolated on the coast of the Alasheyev Bight in the area of the Vecherniy region, the Thala Hills Oasis, Enderby Land, East Antarctica. Strains TMP9 T and TMP25 were isolated from temporary meltwater ponds, while strain G.S.17 T was obtained from a sample of green snow. Strains TMP9 T and TMP25 were motile rods, catalase-negative and oxidase-positive, while G.S.17 T was rod-shaped and exhibited motility, but was catalase- and oxidase-positive. TMP9 T and TMP25 grew at 4–25 °C, pH 5.5–9.0 and tolerated up to 4.5% NaCl. G.S.17 T grew at 4–28 °C, pH 5.0–8.5 and NaCl concentration up to 3.0%. The 16S rRNA gene sequence analysis placed all strains within the genus Pseudomonas : strains TMP9 T and TMP25 are closely related to Pseudomonas peli DSM 17833 Т (99.5% identity), and the strain G.S.17 T exhibits the highest similarity to Pseudomonas rossensis P2663 T (99.1% identity). Whole-genome comparisons using average nucleotide identity suggested that strains TMP9 T and TMP25 represent a novel species within the genus Pseudomonas , which is most closely related to Pseudomonas guineae LMG 24016 T (83.3%). Strain G.S.17 T also represents a novel species within the genus Pseudomonas and is most closely related to Pseudomonas caspiana FBF102 T (80.5%). The predominant cellular fatty acids of strains TMP9 T , TMP25 and G.S.17 T were cis-9-hexadecenoic, hexadecanoic and trans-9-octadecenoic acids. Physiological and biochemical tests, as well as genomic analysis results, clearly differentiated strains TMP9 T , TMP25 and G.S.17 T from type strains of closely related species. Thus, according to the data obtained, two novel species within the genus Pseudomonas are proposed: Pseudomonas vesperimontis sp. nov. (type strain TMP9 T =BIM B-1560 T =VKM B-3887 T ) and Pseudomonas viridinivis sp. nov. (type strain G.S.17 T =BIM B-1635 T =VKM B-3888 T ).
Muratova et al. (Mon,) studied this question.