Lactic Bacteria in Artisanal Cheese: Characterization through Metagenomics

Abstract

Artisanal cheese, produced with raw milk by a predominantly manual approach, has a historical and cultural tradition related to the region of origin. Given its economic and cultural importance, the main objective of this study was to investigate and characterize the diversity of lactic acid bacteria (LAB) of artisanal cheeses produced and traded by family agro-industries in a region of southern Brazil. The LAB composition of artisanal cheese samples, belonging to different municipalities of the Region of Vale do Taquari, were characterized by the next-generation sequencing (NGS) method, amplifying the V3/V4 region of the 16S rRNA gene. A total of 35 LAB species, distributed in seven genera, were identified, and rarefaction analysis suggested that the total diversity assessed by 16S rRNA analysis was high in the analyzed samples. The average Ph ranged from 4.6 to 6.6, and a correlation with the genus Lactococcus (r = 0.62) was the most expressive. The LAB genera identified in the cheese samples were Bavariicococcus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Marinillactibacillus, and Pediococcus. Lactococcus lactis was the most predominant species, present in all samples. Although some species have been identified in the three altitudes studied, the abundance varied according to geographic environments. Enterococcus italicus is more present at high altitudes, unlike Lactococcus plantarum and Lactococcus raffinolactis at low altitudes. Lactococcus lactis was present in the three geographic environments evaluated, but the highest abundance was observed at high altitudes. The identification of LAB present in fermented cheeses is essential to understand the organoleptic quality during the maturation process as well as to establish the shelf life, including the safety and the overall quality of the cheese. This specific microbiota contributes to the flavor and unique characteristics of the regional dairy products, and on the other hand can be a source of specific starter cultures that guarantee the product’s identity.

Microbial Ecology of Pecorino Siciliano PDO Cheese Production Systems

“…However, the starter culture composition of artisanally produced cheeses is only recently being studied in detail to establish its ecology and diversity. Studies of artisanal cheeses associated with different geographical locations and employing distinct milk substrates (bovine, ovine, caprine milk) have described their distinct and diverse microbiota using metagenomic and/or microbiological approaches [2][3][4]. The microbiota analysis of such cheeses has typically been performed using the final product (often ripened) while limited research attention has been devoted to defining the microbiota of such cheeses during the production process, and thus the dominant starter microbiota.…”

Attenuation of Immunogenicity in MOG-Induced Oligodendrocytes by the Probiotic Bacterium Lactococcus Sp. PO3

“…Lactic acid bacteria are widely used in dairy industries to ferment food products through acidification or low pH to preserve them. Moreover, they contribute proteolytic, lipolytic, and organoleptic characteristics to the fermented foodstuffs, such as flavor and texture [13,14]. Generally, low temperatures below 4 • C are preferred for raw milk storage; however, this negatively affects the mesophilic bacteria and favors pathogenic bacteria such as psychotrophic bacteria [13,15,16].…”

“…Moreover, they contribute proteolytic, lipolytic, and organoleptic characteristics to the fermented foodstuffs, such as flavor and texture [13,14]. Generally, low temperatures below 4 • C are preferred for raw milk storage; however, this negatively affects the mesophilic bacteria and favors pathogenic bacteria such as psychotrophic bacteria [13,15,16]. To this end, the pre-maturation method was followed by increasing the storage temperature to favor the desired microbiota, such as Lactococci, which is helpful in developing various cheese products [15,17].…”