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Bacillus paralicheniformis sp. nov., isolated from fermented soybean paste

Dunlap, Christopher A., Kwon, Soon-Wo, Rooney, Alejandro P., Kim, Soo-Jin
International journal of systematic and evolutionary microbiology 2015 v.65 no.10 pp. 3487-3492
Bacillus licheniformis, Bacillus sonorensis, DNA, Gram-positive bacteria, bacitracin, cell walls, endospores, enzyme activity, fatty acids, fermentation, foods, genes, genotyping, isoprenoids, menaquinones, monophyly, new species, nucleotide sequences, pH, peptidoglycans, phenotype, phosphatidylethanolamines, ribosomal RNA, soybeans, strains, urease
An isolate of a Gram-positive, facultatively anaerobic, motile, rod-shaped, endospore forming bacterium was recovered from soybean-based fermented paste. It was isolated from cheonggukjang, a Korean fermented soybean food product. Phylogenetic analysis of the 16S rRNA gene indicated that the strain was most closely related to Bacillus sonorensis KCTC-13918(T) (99.5 %) and Bacillus licheniformis DSM 13(T) (99.4 %). In phenotypic characterization, the novel strain was found to grow between 15-60 °C and to tolerate up to 10% (w/v) NaCL. Furthermore, the strains grew in media with pH 6 to 11 (optimal growth at pH 7.0–8.0). The predominant cellular fatty acids were anteiso-C(15:0) (37.7%) and iso-C(15:0) (31.5'%). The predominant isoprenoid quinone was menaquinone 7 (MK-7). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unknown glycolipid. A draft genome of the strain was completed and used for phylogenetic analysis and comparisons to close relatives. The DNA G+C content was 45.9 mol%. In addition, to forming a distinct monophyletic cluster in phylogenetic analysis of gene sequence data, the strain differed from the two most closely related species in that it produces bacitracin, fengycin, a lantipeptide and does not produce lichenicidin. The strains also contained a 9 gene urease cluster and possessed urease activity, not found in closely related species. A phylogenomic analysis of all published genomes of species in the Bacillus licheniformis group revealed that strains belonging to B. licheniformis clustered into two distinct groups, with group 1 consisting of B. licheniformis DSM 13(T) and 11 other strains and group 2 consisting of KJ-16(T) and 4 other strains. This was consistent with other recent B. licheniformis genotyping studies, which showed that it forms at least two distinct groups. Strain KJ-16 and another strain from group 2 were subsequently characterized using a polyphasic taxonomic approach and compared to two strains from group 1 and other type strains of closely related Bacillus species. Based upon the consensus of phylogenetic and phenotypic analyses, we conclude that this strain represents a novel species within the genus Bacillus, for which the name Bacillus paralicheniformis sp. nov. is proposed, with type strain KJ-16(T) (=KACC 18426(T), = NRRL B-65293(T)).