Seohaeicola nanhaiensis sp. nov., A Moderately Halophilic Bacterium Isolated from the Benthic Sediment of South China Sea

An aerobic, Gram-staining negative, non-motile, and rod-shaped bacterial strain, SS011A0-7#2-2T, was isolated from the sediment of South China Sea with the depth of 1,500 m. Optimum growth occurred at pH 8.0, 30 °C, and 6 % (w/v) NaCl. Strain SS011A0-7#2-2T did not synthesize bacteriochlorophyll a or carotenoid, neither possess photosynthesis genes. Its genome DNA G+C content was 67.9 mol%. It contained Q-10 as the predominant ubiquinone and C18:1ω7c (52.3 %) as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, and unidentified aminolipid. The 16S rRNA gene sequence analysis revealed that it was closely related to Seohaeicola saemankumensis SD-15T, Phaeobacter gallaeciensis BS 107T and Roseovarius pacificus 81-2T in Rhodobacteraceae, with the 16S rRNA gene sequence similarities being 96.5, 95.7, and 95.6 %, respectively. However, the phylogeny of the 16S rRNA gene sequences revealed that strain SS011A0-7#2-2T was a member of the genus Seohaeicola. Strain SS011A0-7#2-2T was moderately halophilic which was different from Seohaeicola saemankumensis SD-15T, and it showed the enzyme activities and carbon source spectrum significantly different from Seohaeicola saemankumensis SD-15T. As its physiological and chemotaxinomic properties were different from those of Seohaeicola saemankumensis SD-15T, strain SS011A0-7#2-2T represents a novel species of the genus Seohaecola. The name Seohaeicola nanhaiensis sp. nov. is proposed, with strain SS011A0-7#2-2T (=LMG 27733T = CGMCC 1.12759T) as the type strain.