Microbulbifer spongiae sp. nov., isolated from marine sponge Diacarnus erythraeanus

A novel bacterium, designated as MI-G , was isolated from marine sponge s . Cells of strain MI-G are Gram-stain-negative, aerobic, and rod or coccoid-ovoid in shape. MI-G is able to grow at 10-40 °C (optimum, 28 °C), with 1.0-8.0% (w/v) NaCl (optimum, 4.0%), and at pH 5.5-9.0 (optimum, pH 8.0). The 16S rRNA gene sequence of strain MI-G shows 98.35, 97.32 and 97.25% similarity to those of Ni-2088 , TF-17 and AM134 , respectively. Phylogenetic analysis also exhibits that strain MI-G falls within a clade comprising members of the genus (class ). The genome size of strain MI-G is 4478124 bp with a G+C content of 54.51 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain MI-G and other type strains are 71.61-76.44% (ANIb), 83.27-84.36% (ANIm) and 13.4-18.7% (dDDH), respectively. These values are significantly lower than the recommended threshold values for bacterial species delineation. Percentage of conserved proteins and average amino acid identity values among the genomes of strain MI-G and other closely related species are 52.04-59.13% and 67.47-77.21%, respectively. The major cellular fatty acids of MI-G are composed of summed feature 8 (C 7 or C 6 ), iso-C 3-OH, iso-C , C , and summed feature 9 (C iso 9 or C 10-methyl). The polar lipids of MI-G mainly consist of phosphatidylethanolamine, phosphatidylglycerol, aminolipid, and two glycolipids. The major respiratory quinone is Q-8. Based on differential phenotypic and phylogenetic data, strain MI-G is considered to represent a novel species of genus , for which the name sp. nov. is proposed. The type strain is MI-G (=MCCC 1K07826 =KCTC 8081 ).