A taxonomic study was performed on 15 bacterial isolates from the caeca of gnotobiotic mice that had been fed with thermophile-fermented compost. The 15 isolates were thermophilic, Gram-stain-positive, facultatively anaerobic, endospore-forming bacteria, and were most closely related to Bacillus thermoamylovorans CNCM I-1378T. The 16S rRNA gene sequence of strain N-11T, selected as representative of this new group, showed a similarity of 99.4% with Bacillus thermoamylovorans CNCM I-1378T, 94.7% with Bacillus thermolactis R-6488T, and 94.4% with Bacillus kokeshiiformis MO-04T. The isolates were then classified into two distinct groups based on a (GTG)5-fingerprint analysis. Two isolates, N-11T and N-21, were the representatives of these two groups, respectively.‘The N-11T and N-21 isolates showed 66–71% DNA–DNA relatedness with one other, but had less than 37% DNA–DNA relatedness with B. thermoamylovorans LMG 18084T. The other 13 isolates showed DNA–DNA relatedness values above 74% with the N-11T isolate. All 15 isolates grew at 25–60 °C (optimum 50 °C), pH 6–8 (optimum pH 7) and were capable of growing on a medium containing 6% (w/v) NaCl (optimum 0.5%). The 15 isolates could be distinguished from B. thermoamylovorans LMG 18084T because they showed Tween 80 hydrolysis activity and did not produce acid from melibiose. The major fatty acids were anteiso-C15:0, C16:0, iso-C15:0, iso-C14:0 and iso-C16:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and several unidentified phospholipids. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The menaquinone was MK-7. The DNA G+C content was 37.9 mol%. Based on the phenotypic properties, the 15 strains represent a novel species of the genus Bacillus, for which the name Bacillus hisashii sp. nov. is proposed. The type strain is N-11T (=NRBC 110226T=LMG 28201T).
|Number of pages||6|
|Journal||International journal of systematic and evolutionary microbiology|
|Publication status||Published - Nov 2015|
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics