A Gram-negative, spirilla, non-spore-forming, motile and strictly aerobic bacterium, designated HK-33T, was isolated from a mangrove sediment sample in Haikou city, Hainan Province, China. Strain HK-33T was able to grow at 10-45 °C (optimum 37 °C), 0.5-12.0 % (w/v) NaCl (2.0 %, w/v) and pH 5.5-8.5 (pH 7.0). The major cellular fatty acids were C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Ubiquinone-8 was the predominant respiratory quinone, and Q-9 was present in trace amounts. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified phospholipids, two unidentified glycolipids, an unidentified aminophosphoglycolipid and two unidentified lipids. The DNA G+C content was 57.3 mol%. According to 16S rRNA gene sequences similarity, strain HK-33T shared 98.6 %, 96.4%, 95.7 and 94.9 % sequence similarities to the species Saccharospirillum correiae CPA1T, Saccharospirillum impatiens EL-105T, Saccharospirillum salsuginis YIM-Y25T and Saccharospirillum aestuarii IMCC 4453T, respectively. Phylogenetic analysis showed that strain HK-33T was clustered with S. correiae CPA1T, S. impatiens EL-105T, S. salsuginis YIM-Y25T and S. aestuarii IMCC 4453T. Results of DNA-DNA hybridization analysis revealed that strain HK-33T shared 36.3±1.7 % DNA relatedness with S. correiae CPA1T. On the basis of its phenotypic, chemotaxonomic and genotypic characteristics, strain HK-33T is considered to represent a novel species in the genus Saccharospirillum, for which the name Saccharospirillummangrovi sp. nov. is proposed. The type strain is HK-33T (=KCTC 62178T=MCCC 1K03440T).
Keywords: Saccharospirillum mangrovi; mangrove sediment; taxonomy.