Physical and microbiological characterisation of artisanal cheese and isolation, identification, and in vitro evaluation of Lactobacillus strains with probiotic potential and antibiotic susceptibility

Abstract

The aim of this study was to isolate lactic acid bacteria (LAB) from artisanal cheeses and evaluate their probiotic potential and antibiotic susceptibility under in vitro conditions. Cheeses obtained at different maturation times were analysed for moisture and lipid contents, as well as for the presence of various microorganisms, including coagulase positive staphylococci, Salmonella spp., Escherichia coli, Listeria monocytogenes, filamentous fungi, yeasts, total mesophilic bacteria, and LAB. After identification, the selected LAB were subjected to human gastrointestinal tract (HGT) conditions to evaluate their survival rates. Of the 18 Lactobacillus strains isolated, 11 survived the HGT test and presented γ-haemolysis. No resistance was observed against antibiotics. Lactobacillus fermentum C1a, C1b, C1c, and C1f, as well as Lactobacillus paracasei C1d, C1e, and C1g, were identified as potential starter cultures for the food industry.