Isolation of anti-listerial bacteriocin producing <italic>Lactococcus lactis</italic> CFR-B3 from Beans (<italic>Phaseolus vulgaris</italic>)

Abstract

Contamination of food samples by Listeria monocytogenes is a major cause of food-borne infections. Controlling the growth of Listeria sp. by application of bacteriocin or bacteriocin producing-organism in foods is one of the challenges in the development of effective bio-preservation process. The objective of this study was to isolate and to characterize bacteriocinogenic strain Lactococcus lactis CFR-B3 from Indian beans. Bacterial strain of Pediococcus acidilactici NRRL B1153 was used as indicator to screen bacteriocin production. The culture was found to produce class IIa heat-stable anti-listerial bacteriocin of MW ~ 5 kDa. The use of food-grade organism as an indicator for screening bacteriocinogenic strains of lactic acid bacteria circumvent the need for using pathogenic cultures such as listeria spp. The native isolate Lc. lactis CFR-B3 finds its application in the preservation of vegetables due to its prevalence in the same ecological niche.