Cytobacillus spongiae sp. nov. isolated from sponge Diacarnus spinipoculum

A novel Gram-stain-positive, aerobic and motile bacterium, designated strain CY-G^T, was isolated from a sponge (Diacarnus spinipoculum) collected from the Red Sea. The strain grew at 13-43 °C (optimum 30 °C), pH 5.5-10.0 (optimum pH 9.0) and with 0-8.0 % (w/v) (0-1.37 M) NaCl (optimum 0 %). The results of phylogenetic analysis based on the 16S rRNA gene sequences indicated that CY-G^T represents a member of the genus Cytobacillus, with the highest sequence identity to Cytobacillus oceanisediminis H2^T (97.05 %), followed by Cytobacillus firmus IAM 12464^T (96.76 %). The major cellular fatty acids (>5 % of the total) of CY-G^T were C_15 : 0iso, C_16 : 0iso, C_16 : 1ω7c alcohol, C_16 : 0, C_17 : 1iso ω10c and C_17 : 0iso. The major polar lipids were glycolipid, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The major respiratory quinone is menaquinone-7 (MK-7). The cell-wall peptidoglycan contains meso-diaminopimelic acid. The total genome size of CY-G^T is 4 789 051 bp. The DNA G+C content is 38.83 mol%. The average nucleotide identity and DNA-DNA hybridization among CY-G^T and type strains of other species of the genus Cytobacillus were 76.79-78.97 % and 20.10-24.90 %, respectively. On the basis of the results of phylogenetic analysis, physiological and biochemical characterization, strain CY-G^T represents a novel species of the genus Cytobacillus, for which the name Cytobacillus spongiae sp. nov. is proposed. The type strain is CY-G^T (=MCCC 1K06383^T=KCTC 43348^T).