Efficacy of purified bacteriocin of L. fermentum L2 in preservation of plum (Prunus domestica) pulp and ready to serve (RTS) plum drink

Abstract

Bacteriocin is used as a preservative in food to curb growth of spoilage and pathogenic bacteria. This study investigated the efficacy of bacteriocin from Lactobacillus fermentum L2 (NCBI accession no. MF443392) to enhance the shelf-life of plum (Prunus domestica) pulp and a ready to serve (RTS) plum drink. Bacteriocin produced from Lactobacillus fermentum L2 was isolated from lassi – a mild, acidic and refreshing buttermilk drink from the Trans-Himalayas. Lactobacillus fermentum L2 produced a bacteriocin of molecular weight 5 kDa which showed an antagonistic action against Staphylococcus aureus. The bacteriocin, with activity units 10×103 AU/ml, was added to plum pulp and its RTS drink as a preservative. The preservative effect of bacteriocin was studied for a period of 30 days and was compared with the preservative effects of sodium benzoate. The comparative study considered changes in the physicochemical characteristics of processed products and assessed microbial load during the storage period. Non-significant changes were observed in physicochemical characteristics of both products. Bacteriocin from L. fermentum L2 was satisfactory in controlling the growth of Staphylococcus aureus and is proven to be a desirable bacteriocin to be used as a natural preservative. The bacteriocin of L. fermentum L2 will be checked against multidrug resistance strains – a growing problem against which researchers are looking for alternative solutions.