Technological Potential of Native Lactic Acid Bacteria from Brazilian Canastra Cheese: Safety and Functional Characterization.

Abstract

Canastra artisanal Minas cheese is a traditional Brazilian raw-milk cheese whose fermentation relies on "pingo", an endogenous whey culture that harbors autochthonous lactic acid bacteria (LAB) with technological relevance. This study evaluated the safety and technological properties of LAB isolated from pingo and cheeses from Serra da Canastra region, Brazil. Among 199 presumptive LAB isolates screened for hemolytic activity, mucin degradation, and antibiotic susceptibility, 116 met the preliminary safety criteria. Rep-PCR and partial 16S rRNA gene sequencing revealed 16 genetic groups, mainly represented by Streptococcus lutetiensis (32%), Lactiplantibacillus plantarum (28%), Lpb. paraplantarum (14%), Lactococcus lactis (12%), and Leuconostoc mesenteroides (12%). Vancomycin resistance genes were not detected, whereas biogenic amine-related genes were identified in some strains, and Enterococcus durans 14A3 produced tyramine in vitro. Technological characterization showed variability in acidification capacity (ΔpH/t24 = 0.010-0.061), proteolytic and lipolytic activities, diacetyl production and enzymatic profiles. Genes associated with bacteriocin production, adhesion, and γ-aminobutyric acid (GABA) synthesis were also detected in selected strains. The integration of safety and technological traits identified Lpb. plantarum 2B3 and L. lactis 6D5 as the most promising candidates, combining favorable safety profiles with consistent technological characteristics. These findings highlight the potential of the autochthonous microbiota of Canastra artisanal Minas cheese as a source of adjunct cultures for artisanal dairy production, while reinforcing the importance of strain-level safety assessment.