Note: Relationship of Bacillus subtilis clades associated with strains 168 and W23: A proposal for Bacillus subtilis subsp. subtilis subsp. nov. and Bacillus subtilis subsp. spizizenii subsp. nov.
Earlier phylogenetic studies based on the inferred DNA sequences of the polC, rpoB and gyrA genes suggested that strains of the species Bacillus subtilis formed two clusters, indicating the presence two closely related taxa; one contained the laboratory strain 168 and the other the laboratory strain W23. Significant sexual isolation was found between strain 168 and members of the group containing W23, but no sexual isolation was observed between strain 168 and other members of the 168 group. DNA reassociation between the two groups ranged from 58 to 69% and intragroup DNA relatedness ranged from 82 to 100%. Because group 168 strains were highly related to the B. subtilis type strain, they were considered to be bona fide members of the species. About 99.5% sequence identity was observed between the 16S rRNA genes of the 168 and W23 groups. Ribitol and anhydroribitol were principal cell wall constituents of the W23 but not of the 168 group. These observations revealed two closely related but genetically and phenotypically distinct groups within B. subtilis that correspond to two historically important strains. Subspecies distinction is proposed for the 168 and W23 groups, with the names Bacillus subtilis subsp. subtilis subsp. nov. and Bacillus subtilis subsp. spizizenii subsp. nov., respectively. The type strain of the former is NRRL NRS-744T and the latte NRRL B-23049T.
ChinT.,
BurgerM. M.,
GlaserL.1966; Synthesis of teichoic acids. VI. The formation of multiple wall polymers in Bacillus subtilis W-23. Arch Biochem Biophys 116:358–367
CohanF. M.,
RobertsM. S.,
KingE. C.1991; The potential for genetic exchange by transformation within a natural population of Bacillus subtilis. Evolution 45:1393–1421
CumminsC. S.,
JohnsonJ. L.1971; Taxonomy of the clostridia: wall composition and DNA homologies in Clostridium butyricum and other butyric acid-producing clostridia. J Gen Microbiol 67:33–46
FoxK. F.,
WunschelD. S.,
FoxA.,
StewartG. C.1998; Complementarity of GC-MS and LC-MS analyses for determination of carbohydrate profiles of vegetative cells and spores of bacilli. J Microbiol Methods 33:1–11
LaneD. L.1991; 16S/23S rRNA sequencing. In Nucleic Acid Techniques in Bacterial Systematics pp. 115–175 Edited by
StackebrandtE.,
GoodfellowM.
New York: Wiley;
NakamuraL. K.,
SwezeyJ.1983; Taxonomy of Bacillus circulans Jordan 1890: base composition and reassociation of deoxyribonucleic acid. Int J Syst Bacteriol 33:46–52
RobertsM. S.,
CohanF. M.1995; Recombination and migration rates in natural populations of Bacillus subtilis and Bacillus mojavensis. Evolution 49:1081–1094
RobertsM. S.,
NakamuraL. K.,
CohanF. M.1994; Bacillus mojavensis sp. nov., distinguishable from Bacillus subtilis by sexual isolation, divergence in DNA sequence, and differences in fatty acid composition. Int J Syst Bacteriol 44:256–264
RobertsM. S.,
NakamuraL. K.,
CohanF. M.1996; Bacillus vallismortis sp. nov., a close relative of Bacillus subtilis, isolated from soil in Death Valley, California. Int J Syst Bacteriol 46:470–475
StackebrandtE.,
GoebelB. M.1994; Taxonomic note: a place for DNA-DNA reassociation and 16S rRNA sequence analysis in the present species definition in bacteriology. Int J Syst Bacteriol 44:846–849
ZawadzkiP.,
RobertsM. S.,
CohanF. M.1995; The log-linear relationship between sexual isolation and sequence divergence in Bacillus transformation is robust. Genetics 140:917–932
Note: Relationship of Bacillus subtilis clades associated with strains 168 and W23: A proposal for Bacillus subtilis subsp. subtilis subsp. nov. and Bacillus subtilis subsp. spizizenii subsp. nov.