| Congresso Brasileiro de Microbiologia 2023 | Resumo: 305-1 | ||||
Resumo:Minas Gerais, a Brazilian state renowned as the largest cheese producer in the country, is home to Minas Artisanal Cheese (MAC). This cheese is produced in various regions of the state using raw cow milk combined with a natural starter culture known as “pingo”. Among these regions is “Entre Serras”, where MAC production had decreased, and in some cases, stopped for decades. However, there has been a recent resurgence in artisanal cheese production in this area. Comprehensive scientific studies are necessary to characterize the production processes, microbial profiles of the cheeses, and their changes during maturation. Therefore, this study aimed to perform the microbiological characterization through 16S rRNA gene amplicon sequencing of “Entre Serras” MAC over 60 days of ripening period. Four different producers/farms (A, B, C, D) located near two different cities were included in this study: cheeses A, B and D were produced in farms close to Santa Bárbara, while cheese C was produced in farm close to Barão de Cocais. A total of 28 MAC samples were obtained during the 2019 autumn (seven from each producer/farm, all from a single monitored lot during ripening); samples were collected on the production day (time 0) and at 7, 15, 21, 30, 45, and 60 days of ripening. For the analysis, we sent subsamples (approximately 25 g) of each cheese to Neoprospecta Microbiome Technologies (Florianópolis, SC, Brazil), where DNA extraction, library preparation, and DNA sequencing were conducted. The V3-V4 regions of 16S rRNA were amplified. The raw MiSeq data were processed using a pipeline owned by Neoprospecta, and the normalized OTU (Operational Taxonomic Unit) values were plotted into a table, grouped based on genus and species identification. The data was then analyzed using the Marker Data Profiling module. Alpha-diversity was evaluated using the Chao1 richness method, with groups classified according to identified genera/species and compared using an ANOVA test (p < 0.05). Metrics of beta diversity (Bray-Curtis index) and Principle Coordinate Analysis (PCoA) were performed using PERMANOVA. The findings indicated that Lactococcus lactis was the predominant species in all cheeses, regardless of the producer/farm. Additionally, other prevalent bacterial genera such as Enterococcus, Streptococcus, Lactobacillus, and Leuconostoc were identified, with varying levels depending on the producer or farm. Farms A and B showed higher levels of contaminants, particularly Enterobacteriaceae and Staphylococcus aureus, likely attributed to inadequate hygiene during cheese production and/or poor management and herd health. Chao1 indices exhibited significant variations when comparing the estimated species richness values among the different producers/farms (p < 0.05). Furthermore, PCoA revealed distinct microbial communities for some farms (p < 0.001), though no statistical significance was observed when grouping according to maturation time. Core microbiota analysis indicated that the microbiota included not only lactic acid bacteria but also spoilage and potentially pathogenic bacteria. Finally, this research provided the first insights into the bacterial diversity of the MAC produced in the “Entre Serras” region, being essential for understanding the microbiological diversity between the different farms in the region. Palavras-chave: artisanal cheese, lactic acid bacteria, microbiome, ripening, 16S rRNA Agência de fomento:CAPES (Financial code 001), CNPq and FAPEMIG | |||||