Minas artisanal cheese, produced in the Campo das Vertentes region of Brazil, is made from raw milk and endogenous starter cultures. Although this cheese is of great historical and socioeconomic importance, little information is available about its microbiological and physical-chemical qualities, or about its beneficial microbiota. This work was aimed at evaluating the qualities of the cheese and the components used for its production, comparing samples collected during the dry and rainy seasons. We also conducted molecular identification and isolated 50 samples of lactic acid bacteria from cheese (n=21), water (n=3), raw milk (n=9), and endogenous starter culture (n=17). The microbiological quality of the cheese, water, raw milk, and endogenous starter culture was lower during the rainy period, given the higher counts of coagulase-positive Staphylococcus and total and thermotolerant coliforms. Enterococcus faecalis was the lactic acid bacteria isolated most frequently (42.86%) in cheese samples, followed by Lactococcus lactis (28.57%) and Lactobacillus plantarum (14.29%). Lactobacillus brevis (5.88%), Enterococcus pseudoavium (5.88%), Enterococcus durans (5.88%), and Aerococcus viridans (5.88%) were isolated from endogenous starter cultures and are described for the first time in the literature. The lactic acid bacteria identified in the analyzed cheeses may inhibit undesirable microbiota and contribute to the safety and flavor of the cheese, but this needs to be evaluated in future research.

The microbiota of lactic acid bacteria (LAB) from Minas artisanal cheese was evaluated. Samples of Minas artisanal cheese were collected at the farms in the region of Araxá, Brazil, over two seasons. Molecular approaches were used to assess the biodiversity of the isolates. The median value of the counts of LAB ranged from 6.4 to 9.5 log units in cheeses throughout the ripening period, in both seasons. The genera of Lactobacillus, Enterococcus, Pediococcus, and Lactococcus were found. L. plantarum and L. rhamnosus were the prevailing species during both seasons, suggesting they may play a role in the development of the cheese attributes. Enterococcus rivorum was identified in one sample and it was probably the first description in cheeses. This is an important report describing the varieties of LAB in this cheese and the identification of its lactic communities could be a source of strains with specific properties.Aislamiento e identificación de las baterias ácido-lácticas del queso brasileño Minas artesanal RESUMEN Se evaluó la microbiota de la bacteria ácido-láctica (BAL) del queso Minas artesanal. Se recogieron muestras del queso Minas artesanal en granjas de la región de Araxá, Brasil, durante dos estaciones. Se utilizaron enfoques moleculares para examinar la biodiversidad de los aislados. El valor medio de los recuentos de BAL fue de entre 6,4 y 9,5 unidades log en los quesos durante el periodo de maduración, en las dos estaciones. Se encontraron los géneros Lactobacillus, Enterococcus, Pediococcus, y Lactococcus. L. plantarum y L. rhamnosus fueron las especies predominantes durante las dos estaciones, sugiriendo que podrían jugar un papel importante en el desarrollo de los atributos del queso. Se identificó Enterococcus rivorum en una muestra y probablemente fue la primera descripción en los quesos. Este es un importante estudio que describe las variedades de BAL en este tipo de queso y la identificación de sus comunidades lácticas podría ser una fuente de cepas con propiedades específicas. ARTICLE HISTORY

The microbiota of the Brazilian Minas artisanal cheese, made from raw milk, is not well known and may include probiotic bacteria. This study aimed to assess the in vitro and in vivo probiotic properties of the lactic acid bacteria isolated from these cheeses. Thirty‐six samples of the Lactobacillus/Pediococcus group were selected for in vitro investigation. Pediococcus acidilactici (PA2) and Lactobacillus plantarum (LP4) showed the best results and were tested for their ability to protect Salmonella Typhimurium orally infected mice. LP4 showed better probiotic potential than PA2 and allowed higher values of weight gain (P < 0.05). Thus, Lb. plantarumLP4 may have potential use as a probiotic in foods after future technological screening.

The consumption of raw milk and its products is a risk factor associated with zoonotic tuberculosis. Lactic acid bacteria (LAB) show inhibitory activity against Mycobacterium bovis, the causative agent of tuberculosis. The aim of this study was to assess the in vitro antagonistic activity of LAB from Brazilian Minas artisanal cheese against M. bovis bacillus Calmette-Gu erin (BCG). Nine LAB were tested against M. bovis BCG in five in vitro antagonistic assays. Four lactobacilli gave the best results in all the experiments. This could be due to their growth rate, acid and bacteriocin production. In conclusion, LAB are capable of inhibiting M. bovis BCG viability.

Staphylococcus aureus is one of the main causative agents of food poisoning. This bacterium is an important component of cheese microbiota and plays an important role in foodborne diseases. Another important component of the microbiota is the lactic acid bacterium, which actively participates in processes that define the physicochemical, sensorial, and microbiological features of cheese. Of the various microbiological interactions in cheese, the interaction between lactic acid bacteria and Staph. aureus is most relevant. To this end, we evaluated the viability of Staph. aureus strains and the expression of their enterotoxins in cheeses produced experimentally, using Weissella paramesenteroides GIR16L4 or Lactobacillus rhamnosus D1 or both as starter cultures. Over 7 d, we observed that the presence of lactic acid bacteria did not impair Staph. aureus growth. However, via qPCR we observed a change in the gene expression of staphylococcal enterotoxins, suggesting that molecular communication exists between Staph. aureus strains and lactic acid bacteria in cheese.