Isolation, identification, and antimicrobial activity of lactic acid bacteria associated with two traditional Colombian types of cheese: Quesillo and double-cream cheese

The Quesillo and Double-Cream, two traditional pasta filata fresh cheeses from the Colombian Andean region, were studied for their microbiological composition including lactic acid bacteria (LAB), volatile diacetyl and acetoin compounds, fatty acid profile, and antimicrobial activity against Listeria monocytogenes ATCC-7644 and Salmonella enterica subsp. enterica serovar Typhimurium ATCC-13311. The counts of indicator microorganisms were consistent with those found in this product. The fatty acid composition varied, with oleic and palmitic acids having the largest concentrations. The aroma precursor compound acetoin was detected in both kinds of cheese. The most prevalent species in both products was Lactococcus lactis, which was followed by Enterococcus faecium and Limosilactobacillus fermentum. The inhibition against the pathogens under study was seen in the cell-free supernatants of L. lactis (Quesillo 37-41), L. fermentum (Quesillo 40-74; Double-Cream 104) and Lacticaseiba-cillus paracasei (Double-Cream 101) with good activity at pH 7.0 and 60 degrees C. The antimicrobial activity of L. paracasei (Double-Cream 101) and L. fermentum (Double-Cream 104) against Listeria monocytogenes at all temperatures and times analyzed was highlighted. These findings suggest that the LAB used in this study, which was derived from artisanal cheeses, has bioprospecting potential for application in the elaboration of these traditional products and new dairy products.