Characterization of Oaxaca raw milk cheese microbiota with particular interest in Lactobacillus strains

Abstract

The aim of this work was to identify and characterize lactobacilli strains from Mexican Oaxaca cheese. Twenty-seven lactobacilli isolated from Oaxaca cheese were identified at species level by 16S rRNA sequencing. Selected isolates were further characterized by ribotyping. Isolates were screened, among others, by acidifying capacity, antibiotic resistance, and activity against pathogens. Lactobacillus plantarum was predominant in Oaxaca cheese. The intraspecies variability of Lb. plantarum isolates was great. Multiple antibiotic resistances were observed. Eight isolates showed antimicrobial activity against the pathogenic species tested. Four Lb. plantarum strains showing low antibiotic resistance index, antimicrobial activity against enterotoxigenic Staphylococcus aureus and Listeria innocua stains, amine-negative decarboxylase activity, and resistance to NaCl and bile salt solutions, could be preselected to complete studies focused on designing a culture for use in pasteurized-milk Oaxaca cheese manufacturing.