Characterization of a new bacteriocin produced from a novel isolated strain of Bacillus lentus NG121.

The new bacteriocin is produced from Bacillus lentus NG121 isolated from Khameera - a traditional fermented food from Himachal Pradesh, India which has been reported for the first time in the literature to produce bacteriocin and exhibited very high activity units of 20 x 10(5) AU (Arbitrary Units)/ml. This bacteriocin was partially purified and was further characterized to assess its preservation characteristics. It showed strong antimicrobial activity against the most challenging and serious test indicators like Listeria monocytogens and Staphylococcus aureus. There was a drastic decrease up to 70% in viable cells of the indicators within the first 10 h of adding partially purified bacteriocin thus proving its bactericidal action. It could withstand the high heat of 100 degrees C for 10 min of heating time without losing any activity. A wide range of pH tolerance i.e. from 5.0-10.0 was expressed by this bacteriocin. It was found completely sensitive to proteolytic enzyme trypsin. The unique combination of all the above mentioned characteristics makes the bacteriocin of newly isolated Bacillus lentus NG121, a food grade bacteria, highly desirable for preservation of different food items in the food industry.