Abstract: The antibacterial activity of a novel bacterial strain,identified as Paenibacillus sp.BD3526,was assayed.The antimicrobial component was extracted from Paenibacillus sp.BD3526 cells with acetone and purified on Sephadex LH-20 column.The minimum inhibitory concentrations of the crude extracts were 12.5 mg/mL for Micrococcus luteus CGMCC1.1848, 25 mg/mL for Staphylococcus aureus CGMCC1.879 and Listeria monocytogenes CGMCC1.9136,while the minimum inhibitory concentrations of the preliminarily purified fraction were 1 mg/mL for Micrococcus luteus CGMCC1.1848,2 mg/mL for Staphylococcus aureus CGMCC1.879 and Listeria monocytogenes CGMCC1.9136,respectively. The antimicrobial activity was fairly stable over a wide range of pH values,different heat treatments,but disappeared after digestion by pronase.Therefore,the antimicrobial agent produced by Paenibacillus sp.BD3526 is bacteriocin-like,and potentially useful in food and medical industry.

Key words: Paenibacillus sp., antimicrobial activity, isolation and purification, minimum inhibitory concentration