Shouchella tritolerans sp. nov., a facultative anaerobic bacterium isolated from marine sediments

An alkali, salt, and thermo-tolerant strain designated FJAT-45399(T) was isolated from marine sediment in Fujian Province, China. Strain FJAT-45399(T) was Gram-stain-positive, rod-shaped, and facultatively aerobic. It shared high 16S rRNA gene sequence similarities with the members of the genus Shouchella. Further, the phylogenetic and phylogenomic analysis also suggested strain FJAT-45399(T) clustered with the members of the genus Shouchella. Growth of strain FJAT-45399(T) was observed at 15-55 degrees C (optimum 45-50 degrees C), pH 7.0-13.0 (optimum 9.0) and 0-15% (w/v) NaCl (optimum 2%). It contained MK-7 as the menaquinone. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and an unidentified glycolipid (UGL) and lipid (UL). The major fatty acids (> 10%) were C-16:0 (22.8%), iso-C-15:0 (21.3%), and anteiso-C-15:0 (14.0%). The genomic DNA G + C content was 44.5%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain FJAT-45399(T) and the most closely related type strain Shouchella clausii DSM 8716(T) (ANI 94.1% and dDDH 55.4%) were both below the cut-off level for species delineation. Based on the above results, strain FJAT-45399(T) represents a novel species of the genus Shouchella, for which the name Shouchella tritolerans sp. nov., is proposed. The type strain is FJAT-45399(T) (= GDMCC 1.3098(T) = JCM 35613(T)).