Halomonas endophytica sp. nov., isolated from liquid in the stems of Populus euphratica.

A Gram-stain-negative, aerobic, motile and rod-shaped bacterium, designated MC28, was isolated from storage liquid collected from the stems of Populus euphratica in the Xinjiang province of China. The growth range of NaCl concentration was 0.5-6.0 % (w/v), with an optimum at 3.0 % (w/v), the temperature range for growth was 10-45 °C, with an optimum at 40 °C, and the pH range for growth was 6.0-9.0, with an optimum around pH 8.5. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MC28 formed a distinct lineage in the clade of genus Halomonas and is closely related to Halomonas desiderata DSM 9502 (96.4 %), Halomonas heilongjiangensis DSM 26881 (96.2 %) and Halomonas urumqiensis JCM 30202 (95.2 %). The average nucleotide identity, average amino acid identity and in silico DNA-DNA hybridization values between strain MC28 and the references strains were 77.2-80.3, 65.8-76.8 and 21.6-25.6 %, respectively. Chemotaxonomic analysis indicated that the main respiratory quinones were Q-9 and Q-8, the predominant cellular fatty acids were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω9c, C16 : 0 and C17 : 1ω9c, the major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannoside, an aminophospholipid, an unidentified phospholipid, an unidentified aminolipid and two unidentified lipids. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain MC28 is considered to represent a novel species, for which the name Halomonas endophytica sp. nov. is proposed. The type strain is MC28 (=KCTC 52999=MCCC 1K03343).