New Insights into the Taxonomy of Bacillus and Related Genera in Relevance to Their Antimicrobial Peptides

In the era of changing trend in Bacillus taxonomy, the molecular characterization based on sequencing of amino acids of antimicrobial peptides produced by Bacillus species for its taxonomical classification is gaining importance among the researchers. Bacillus species produces large and unique group of antimicrobial peptides. Conventionally, 16s rRNA sequencing is used for molecular identification of Bacillus. Due to increasing deposition of Bacillus 16s rRNA partial sequences in the most commonly used genomic database (NCBI) resulted in difficulty in identification and differentiation of Bacillus species which are genetically related. Though other conserved genes like rpoB, gyrB, etc. have been supplemented for identification, they are found to be less robust as compared to 16s rRNA sequencing. Therefore, it is a high time to relook the taxonomy of Bacillus in a different perspective. A combination of 16s rRNA or other conserved gene sequencing along with amino acid sequencing of primary sequences of antimicrobial peptides provides authentic information for classification of Bacillus group. In this chapter, taxonomic developments, antimicrobial peptides, and changing pattern in taxonomy of Bacillus species are discussed.