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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 6C (optimal growth at 33-35 6C) 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 (5CECT 7206 T 5CCM 7397 T ).The genus Halobacillus was first described by Spring et al. (1996) et al., 2005). Besides the ability to produce ellipsoidal or spherical endospores at the central or subterminal position, one of the main features of the genus Halobacillus is the cell-wall peptidoglycan type based on L-Orn-D-Asp, in contrast to the meso-diaminopimelic acid or L-lysine type cell-wall peptidoglycan found in related genera (Shida et al., 1997;Yoon et al., 2003). There have been no previous reports of members of the genus Halobacillus associated with mangroves that thrive in saline habitats.Avicennia germinans (black mangrove) is a type of mangrove that has developed mechanisms to tolerate high salt concentrations in unstable substrates, to obtain oxygen from almost anoxic sediments and to reproduce under harsh environmental conditions. One of these mechanisms is the ability to secrete salt crystals on to the surface of its leaves when the salt concentration is in excess of that normally present in the vascular system (Lugo & Snedaker, 1975). In the present study, we determined the taxonomic position of bacterial strain MS10 T , which was isolated from the surface of leaves of the black mangrove during a microbial diversity study. On the basis of the results presented, we show that strain MS10 T represents a novel species of the genus Halobacillus.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain MS10 T is DQ888316. & Gibbons, 1960). This p...

A Gram-negative, short rod to oval-shaped bacterium (strain MW2a T ) was isolated from the surface of leaves of the black mangrove Avicennia germinans and subjected to a polyphasic taxonomic study. Strain MW2aT was moderately halophilic, growing at NaCl concentrations in the range 0-25 % (w/v) with optimum growth at 5 % (w/v) NaCl. Growth occurred at 12-40 6C (optimum, 30-35 6C) and at pH 5.0-9.0 (optimum, pH 7.0-8.0). Strain MW2a T was strictly aerobic.Phylogenetic analysis based on the 16S rRNA gene showed that the strain belongs to the genus Halomonas. The closest relative was Halomonas marisflavi, with 98.6 % 16S rRNA gene sequence similarity. The DNA G+C content of strain MW2a T was 61.5 mol%, which is in the range of values for Halomonas species. DNA-DNA hybridization with H. marisflavi showed a relatedness of 42 % and lower values were obtained with respect to other related Halomonas species. The major fatty acids were C 16 : 0 , C 19 : 0 cyclo v8c, C 18 : 1 v7c and C 12 : 0 3-OH. Overall, the phenotypic, genotypic and phylogenetic results presented in this study demonstrate that strain MW2aT represents a novel species within the genus Halomonas. The name Halomonas avicenniae sp. nov. is proposed, with strain MW2a T (=CECT 7193 T =CCM 7396 T ) as the type strain.The genus Halomonas belongs to the family Halomonadaceae within the Gammaproteobacteria and at the time of writing comprised 35 species that had been isolated mainly from saline or hypersaline environments (Arahal et al., 2002;Bouchotroch et al., 2001;Dobson & Franzmann, 1996;Garcia et al., 2004;Lee et al., 2005; Lim et al., 2004; Martínez-Cánovas et al., 2004; Martínez-Checa et al., 2005;Mata et al., 2002; Mormile et al., 1999; Quillaguaman et al., 2004;Romanenko et al., 2002;Ventosa et al., 1998;Vreeland et al., 1980;Yoon et al., 2001Yoon et al., , 2002 or from unusual habitats such as dry mural paintings (Heyrman et al., 2002) and deep-sea hydrothermal vents (Kaye et al., 2004). Phylogenetic analysis using the 16S and 23S rRNA gene sequences and phenotypic studies demonstrated that this genus is very heterogeneous (Arahal et al., 2002;Mata et al., 2002). One distinct group is represented by a single species, Halomonas marisflavi (Yoon et al., 2001). To date, there have been no reports of the occurrence of members of this genus being associated with mangroves that thrive on saline habitats. Avicennia germinans is a type of mangrove that has developed mechanisms to tolerate high salt concentrations in unstable substrates, to obtain oxygen in almost anoxic sediments and to reproduce in harsh areas. One of these mechanisms consists of the secretion of salt crystals on the leaves when the concentration is in excess of that normally present in the vascular system (Lugo & Snedaker, 1975). In this study, we determined the taxonomic position of strain MW2a T , which was isolated from the surface of leaves of the black mangrove A. germinans during a microbial diversity study. As a result of our studies, the name Halomonas avicenniae sp. nov. is propose...