Phylogeny of marine Bacillus isolates from the Gulf of Mexico

The phylogeny of 11 pigmented, aerobic, spore-forming isolates from marine sources was studied. Forty-two biochemical characteristics were examined, a nd a 16S rDNA sequence was obtained for each isolate. In a phylogenetic tre e based on 16S sequencing, four isolates (NRRL B-14850, NRRL B-14903, NRRL B-14907, and NRRL B-13908) clustered with B. subtilis and related organisms ; NRRL B-14907 was closely related to B. amyoliquefaciens. NRRL B-14907 and NRRL B-14908 were phenotypically similar to B, amyloliquefaciens and B. pu milus, respectively. Three strains (NRRL B-14906, NRRL B-14910, and NRRL B- 14911) clustered in a clade that included B. firmus, B, lentus, and B. mega terium. NRRL B-14910 was closely related phenotypically and phylogeneticall y to B, megaterium. NRRL B-14905 clustered with the mesophilic round spore- producing species, B. fusiformis and B. sphaericus; the isolate was more cl osely related to B, fusiformis. NRRL B-14905 displayed characteristics typi cal of the B. spaericus-like organisms. NRRL B-14909 and NRRL B-14912 clust ered with the Paenibacillus species and displayed characteristics typical o f the genus. Only NRRL B-14851, an unusually thin rod that forms very small spores, may represent a new Bacillus species.