A taste of North Macedonia: Seasonal variation in the microbiota, physico-chemical traits, and morpho-textural profile of a traditional brined raw goat's milk cheese

This study provides a comprehensive characterization of a traditional Macedonian brined raw goat's milk cheese, focusing on how seasonal production (spring vs. autumn) shapes its physicochemical traits, morpho-textural properties, and microbial ecology. Cheese samples produced in autumn exhibited stronger acidification, higher titratable acidity, lower water activity, and higher NaCl content than spring cheeses, reflecting variability associated with artisanal, non-standardized processing. Texture profile analysis showed that cohesiveness and springiness were significantly affected by season, whereas hardness and adhesiveness remained comparable across batches. A combined culture-dependent and 16S rRNA gene-based metataxonomic approach revealed seasonally distinct microbiota. Viable microbial populations composed of mesophilic aerobes (up to 6.51 log cfu g^-1 at 60 days of ripening), presumptive mesophilic lactobacilli and lactococci (up to 6.51 and 7.18 log cfu g^-1 at 60 days of ripening, respectively), presumptive coagulase-negative and coagulase-positive staphylococci (up to 6.97 and 1.76 log cfu g^-1 at 60 days of ripening, respectively), and Enterobacteriaceae (up to 1.25 log cfu g^-1 at 60 days of ripening) were detected. Spring cheeses were characterized by higher relative abundances of Carnobacteriaceae, Enterococcus, Serratia, and Tetragenococcus halophilus, whereas autumn cheeses were dominated by Companilactobacillus and Lactococcus, alongside various Enterobacteriaceae. Beta-diversity analysis confirmed significant clustering of cheese microbiota by season. In total, 134 lactic acid bacteria isolates were obtained from the dairy environment, milk, brine, and cheese. These included Lactococcus lactis, Levilactobacillus brevis, multiple Enterococcus species, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Marinilactibacillus psychrotolerans, and Companilactobacillus alimentarius. Many isolates showed strong proteolytic activity, several produced exopolysaccharides, and a subset exhibited lipolytic capacity, underscoring their technological potential. Screening for the histidine decarboxylase gene hdcA revealed that only the C. alimentarius isolate was positive, excluding this strain from consideration as an adjunct culture, whereas all other isolates were hdcA-negative and therefore suitable candidates from a histamine-safety perspective. Overall, this integrated analysis highlights the rich microbial diversity and seasonal variability of this artisanal cheese and supports the selection of safe autochthonous lactic acid bacteria for future product valorization.