Halobacillus mangrovi sp. nov., a moderately halophilic bacterium isolated from the black mangrove Avicennia germinans

1 Biology Department, Box 9012, University of Puerto Rico, Mayagüez, Puerto Rico 00681 2 Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain Correspondence Rafael Montalvo-Rodríguez titomontal{at}yahoo.com A moderately halophilic, spore-forming, Gram-positive, short-rod-shaped bacterium, designated strain MS10 T , was isolated from the surface of leaves of the black mangrove Avicennia germinans and was subjected to a polyphasic taxonomic study. Strain MS10 T was able to grow at NaCl concentrations in the range 5–20 % (w/v) with optimum growth at 10 % (w/v) NaCl. Growth occurred at temperatures of 10–50 °C (optimal growth at 33–35 °C) and pH 6.0–9.0 (optimal growth at pH 7.0). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MS10 T fell within the branch encompassing members of the genus Halobacillus and was most closely related to Halobacillus dabanensis JCM 12772 T (99.2 % 16S rRNA gene sequence similarity). The DNA G+C content of strain MS10 T was 45.7 mol%, the major respiratory isoprenoid quinone was MK-7 and the cell-wall peptidoglycan was of the L -Orn– D -Asp type, characteristics consistent with its affiliation to the genus Halobacillus . Strain MS10 T showed a level of DNA–DNA hybridization with H. dabanensis JCM 12772 T of 29 % and levels below 70 % were also obtained with respect to other recognized members of the genus Halobacillus . The major fatty acids of strain MS10 T were iso-C 16 : 0 , anteiso-C 15 : 0 , iso-C 14 : 0 and iso-C 15 : 0 . Overall, the phenotypic, genotypic and phylogenetic results presented in this study demonstrate that strain MS10 T represents a novel species of the genus Halobacillus , for which the name Halobacillus mangrovi sp. nov. is proposed. The type strain is MS10 T (=CECT 7206 T =CCM 7397 T ). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain MS10 T is DQ888316 .