Phyletic evolution and taxonomic characteristics of Bacillus

The traditional classification of Bacillus was done mainly based on the phenotypic characteristics.There were 244 species of Bacillus cited in the book of the"Literature Review on Bacillus"by Liu(2006).With the development of new identification methodologies,especially the polyphasic taxonomical method,changes in the taxonomy of Bacillus are emerging.Many species have been re-classified from the genus into new genera.Based on the second edition of "Bergey's Manual of Systematic Bacteriology" published in 2004,this paper discusses the evolutional evidence,as well as the characterictics of the typical species of Bacillus related genera.According to the spore-forming,16S rRNA and other characteristics,22 Bacillus related genera have been separated from Bacillus.Of the 22 genera,15 belong to Bacillaceae and 7 are non-Bacillaceae.There are 13 genera that are only Bacillus in name.