This study presents bacteriocin, produced from Bacillus sp. MTCC 43 isolated from rhizosphere of root crop radish, Raphanus sativus, as inhibitor against serious food pathogens (Staphylococcus aureus and Aeromonas hydrophila). Bacteriocin of Bacillus sp. MTCC 43, partially purified by salt saturation method, exhibits very high activity (2.66 x 105 AU/ml). Viability of pathogens decreased drastically (up to 70%) within first 10 h of adding bacteriocin. Bacteriocin showed high thermostability (up to 100