Sphingomicrobium Clamense Sp. Nov., Isolated from Sediment of Clam Island Beach in China

A Gram-stain-negative, non-flagellated, aerobic, ovoid or rod-shaped bacterium with motility, designated B8, was isolated from the sediment of Clam Island beach, Liaoning province, China. The optimum growth of strain B8 occurred at 35 C, pH 7.0, and in the presence of 4.0-5.0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B8 formed a distinct lineage within the genus Sphingomicrobium and was closely related to Sphingomicrobium nitratireducens O-35 (98.3% sequence similarity), Sphingomicrobium aestuariivivum KCTC 42286 (96.9%), and Sphingomicrobium astaxanthinifaciens JCM 18551 (96.5%). The digital DNA-DNA hybridization and average nucleotide identity values between strain B8 and closely related strains were lower than 21.0% and 78.0%, much lower than the cutoff values of 70.0% and 95.0%, respectively, for bacterial species delineation. The dominant respiratory quinone of strain B8 was ubiquinone-10. The major fatty acids were Sum In Feature 8 (Cω7c and/or Cω6c), Sum In Feature 3 (Cω7c and/or Cω6c), Cω6c, C 2-OH, and C. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, glycolipids, and four unknown polar lipids. The DNA G + C content of strain B8 was 63.9%. Based on the phenotypic, phylogenetic, and chemotaxonomic analyses, strain B8 is considered a new species of Sphingomicrobium, for which the name Sphingomicrobium clamense sp. nov. is proposed. The type strain is B8 (= CGMCC 1.19486 = KCTC 92052).