Abstract

In industrialized countries 30 percentage population suffer from food borne disease yearly. Food processing runs the risk of significant economic loss annually due to food spoilage resulting from microbial contamination. Although chemical preservatives may provide a solution, the use of such preservatives is generally avoided, since they have negative consequences for human health. Moreover, the problems associated with food safety especially of microbial contamination appear to be alarmingly high. To address the increasing bacterial resistance to conventional antibiotics, bacteriocins are now considered as alternative antimicrobials for the treatment of human and possibly animal infections. Further, processed foods without chemical preservatives are in demand by consumers. Research in natural antimicrobial agents such as bacteriocins becomes inevitable. Members of the Bacillus group are good producers of antimicrobial substances such as peptide and lipopeptide antibiotics, as well as bacteriocins. Interestingly, Bacillus represents an alternative genus for the identification of bacteriocins because it includes many industrial species and has a history of safe use in the food industry. In the present study screening of bacterial isolates for bacteriocin production were screened from soil samples, from them thirty bacterial isolates obtained were tested for the bacteriocin activity against indicator bacteria Staphylococcus aureus. Among them MA5 designated strain found to be Gram’s positive rod bacteria. Based on the phenotypical characterization identified as Bacillus sp. and exhibited antagonistic activity against S. aureus. The antagonistic bacterial strain MA5 found to inhibit the growth of S. aureus. Antibacterial activity was identified by agar well diffusion assay. The sensitivity of the indicator strains were estimated based on the inhibition zones. To estimate the molecular weight of the bacteriocin, SDS-PAGE was performed and the protein in the active fraction was resolved and the molecular weight of the single protein band that exhibited antimicrobial activity was estimated to be 10 kDa.

Keywords

Bacteriocin, Methicillin Resistant, SDS-PAGE, Staphylococcus aureus.  

Received on 05/02/2017, Accepted on 01/06/2017, Published on 26/06/2017