Antimicrobial effect of bacteriocin from Lactobacillus fermentum isolated from goat milk on perishable foods. San Luis. Argentina

MITJANS, N.; CORIA, M.; ALFONSO, J.; STAGNITTA, P.

International Journal of Engineering Research & Science (IJOER)

AD Publications

Lugar: Bikaner; Año: 2018 vol. 4 p. 35 - 42

2395-6992

Strain selected for this study was isolated and named as sl36, from samples of goat milk collected from stainlesssteel drums in a dairy farm (San Luis, Argentina). The LAB strain was biochemically typified as Lactobacillus fermentumand designated as L. fermentum sl36. This identification was confirmed by 16S rRNA full sequences. The selected strainshowed antimicrobial activity against food-borne pathogens, Listeria monocytogenes, Listeria innocua, Staphylococcusaureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. The inhibitory activity was lost aftertreatment with trypsin, which indicates that this activity is due to a protein nature substance compatible with bacteriocinsproduced by Gram positive bacteria.The inhibitory substance was stable at different pH and temperatures. Perishable foodsamples (semi-hard cheese, cream, cooked pork shoulder) were treated with cell free supernatant from studied strain andthen with indicator S. aureus and E. faecalis bacteria suspensions. Lactobacillus fermentum sl36 caused the inhibition of thegrowth of E. faecalis and S. aureus in the treated foods. Our work shows that it is possible to increase the safety of foodperishable directly using the bacteriocins produced by the LAB strains, difference from the more frequent practice of usingthe bacteria themselves as probiotics.