Halomonas Humidisoli Sp. Nov., Isolated From Saline-Alkaline Soil

A Gram staining-negative, halophilic, aerobic, non-motile bacteria, designated strain WN018, were isolated from the natural saline-alkali wetland soil of Binhai new district, Tianjin, China (38°46'N, 117°13'E). Cells of strain WN018 were short rod-shaped, 0.3-0.4 µm wide and 0.5-1.9 µm long, and growth occurred optimally at 30-33 °C, pH 7.5-8.0, and in the presence of 4-8% (w/v) NaCl. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genus Halomonas, exhibiting highest sequence similarity of 97.50% to Halomonas venusta DSM 4743T. The DNA G+C content of the strain was 63.8%. The distinct phylogenetic position and phenotypic traits distinguished the novel isolate from its nearest neighbors. The major respiratory quinone of strain WN018 was Q-9 (91.0%) and Q-8 (9.0%), and the dominant fatty acids were C, C, C, C 3-OH. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), three phospholipids (PL), aminolipid (AL), and two unidentified lipids (L). The average nucleotide identity (ANI) based on whole-genome sequences of strain WN018 and Halomonas hydrothermalis DSM 15725 was 93.02%, and the dDDH value between these two strains was determined to be 49.7%. Therefore, we propose a novel species in the genus Halomonas to accommodate the novel isolate: Halomonas humidisoli sp. nov. (type strain WN018 = ACCC 19975 = KCTC 52854).