Antimicrobial potential of bacillus sp EIKU1 isolated from soil

Abstract

Raising incident of antibiotic resistance and the fear of being pushed back to pre-antibiotic era, the search for new molecules capable of restricting pathogen have become extremely important. Antimicrobial peptides produced by bacteria from natural environment holds a promise as an alternative to conventional drug discovery strategies. Unlike that of eukaryotes, antimicrobial peptides from bacteria are specific and effective at low concentration and have been used for different biotechnical methods such as in food preservation, agriculture and therapeutics. Species of Bacillus are generally considered safe to use and known to harbour clusters of gene that code for antimicrobial peptide that are active against pathogens including antibiotic resistant bacteria. Owing to wide genetic and phenotypic heterogeneity, study of Bacillus holds potential for isolation of novel antimicrobial molecules. Rhizosphere is a rich source of microorganisms and many of these organisms are known to secrete diverse molecules that restrict growth of other organisms. newlineThis thesis describes an effort that has been made to isolate, characterize a soil bacterium which was observed to inhibit the growth of another isolate. The isolates were designated as EIKU1 and EIKU2 respectively. This isolation method ensured wild nature of the active components which was readily secreted, so easy to available. Molecular analysis of 16S rRNA gene sequence showed the isolate producing antimicrobial compound is affiliated to the genus Bacillus and the sensitive isolate is a member of Ochrobactrum. Phylogenetic analysis indicated EIKU1 as a novel isolate with Bacillus cereus and Bacillus mycoid as close member and is named as Bacillus sp. EIKU1. newlineBacillus sp. EIKU1 is a facultative anaerobes, rod shaped, spore former bacteria. The culture secretes yellow pigment in both liquid and solid media. Under microscope, the organism appears both single and in chain of bacterial cell measuring ~ 3 × 1 and#956;m. Bacillus sp. EIKU1 produces various extracellular enzymes viz