Antimicrobial activity of Bacillus cereus: Isolation, identification and the effect of carbon and nitrogen source on its antagonistic activity

Abstract

The present study is concerned with the taxonomy and influences of some cultural conditions on growth and antimicrobial metabolite production of a strain of Bacillus cereus, isolated from Alba’qa, Jordan, and designated NBS1, which is a highly active against a variety of Gram positive bacteria, and less activity was noted against filamentous fungi and yeasts, whereas no activity was detected against tested Gram negative bacteria. In order to optimize the culture conditions for the production of antimicrobial metabolite, the effect of different carbon and nitrogen sources were determined. Effects of nutritional compounds on production of antimicrobial compounds showed that the highest antimicrobial activity was obtained when arabinose and glycerol at 3.5 g/100 (w/v) level was used as sole carbon source. Ca(NO3)2 was identified as a nitrogen source that significantly affected antibiotic production. The results showed that strain NBS1 was a potential soil microorganism with antimicrobial activity and may be used for pharmaceutical and biotechnological purposes.\t \tKey words: Antimicrobial substances, Bacillus cereus, carbon source, fermentation, nitrogen source.