In Vitro Probiotic Potential of Lactic Acid Bacteria Isolated from Minas Artisanal Cheese Produced in Serra da Canastra, Brazil

Introduction: In Brazil, artisanal cheeses made of raw milk have social, economic, and cultural importance. Lactic acid bacteria (LAB) are the main component of their desirable microbiota and may play important roles such as development of flavor and protection against undesirable bacteria.

Purpose: This work aimed to select LAB previously isolated from Minas artisanal cheeses produced in Serra da Canastra, Brazil, according to their probiotic properties to produce novel foods in the future.

Methods: The probiotic profile of 12 samples of LAB (11 Lactobacillus spp. and one Weissella paramesenteroides) isolated from artisanal cheeses and identified by PCR-ARDRA 16S-23S was in vitro evaluated by antimicrobial susceptibility using agar diffusion disk test, antagonism against pathogens and LAB, and tolerance to gastric pH and biliary salts. All tests were carried out in triplicate, with three repetitions and the means were compared by the Kruskal-Wallis test (P < 0.05).

Results: All LAB were sensitive to clindamycin, erythromycin, and tetracycline and resistant to vancomycin. L. rhamnosus B4, W. paramesenteroides C10, and L. rhamnosus D1 showed resistance to fewer antimicrobials (ceftazidime, oxaciclin, streptomycin, and vancomycin). All LAB showed higher inhibition halos (P < 0.05) against pathogens than against other LAB isolated from the same cheeses.  Regarding gastric pH tolerance, all samples showed low inhibition of growth at pH 2. The tolerance to biliary salts varied from low to high among the tested samples.

Significance: L. rhamnosus B4, W. paramesenteroides C10, and L. rhamnosus D1 showed the best probiotic potential and may be used to improve the sanitary quality of artisanal cheeses preserving their microbial identity.