The use of natural milk culture (NMC) represents a key factor in PDO Montasio cheeses, contributing to its distinctive sensory profile. The complex microbial ecosystem of NMCs is the result of heat treatment and incubation conditions, which can vary considerably among different production plants. In this study, the microbiota of NMCs collected from 10 PDO Montasio cheese dairies was investigated employing colony counts and metagenomic analysis. Furthermore, residual sugars, organic acids, and volatile profiles were quantitatively investigated. Results showed that was the dominant species in all NMCs, and a subdominant population made of other streptococci and was also present. The incubation temperature appeared to be the main driver of biodiversity in NMCs. Metagenomics allowed us to evidence the presence of minor species involving safety (e.g., ) as well as possible functional aspects (Next Generation Probiotics). Statistical analysis based on residual sugars, organic acids, and volatiles' content allowed to correlate the presence of specific microbial groups with metabolites of great technological and sensory relevance, which can contribute to giving value to the artisanal production procedures of NMCs and clarify their role in the creation of the characteristics of PDO Montasio cheese.

中文翻译：

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探索用于奶酪制作的天然奶培养物的微生物多样性的综合方法

天然奶培养物 (NMC) 的使用是 PDO Montasio 奶酪的一个关键因素，造就了其独特的感官特征。NMC 复杂的微生物生态系统是热处理和孵化条件的结果，不同生产工厂的微生物生态系统可能存在很大差异。在这项研究中，采用菌落计数和宏基因组分析对从 10 个 PDO Montasio 奶酪乳制品厂收集的 NMC 微生物群进行了研究。此外，还对残留糖、有机酸和挥发性成分进行了定量研究。结果表明，它是所有 NMC 中的优势菌种，并且还存在由其他链球菌组成的次优势菌群。孵化温度似乎是 NMC 生物多样性的主要驱动因素。宏基因组学使我们能够证明涉及安全性（例如）以及可能的功能方面（下一代益生菌）的小物种的存在。基于残留糖、有机酸和挥发物含量的统计分析可以将特定微生物群的存在与具有重大技术和感官相关性的代谢物联系起来，这有助于为 NMC 的手工生产程序赋予价值，并阐明它们在创造了PDO蒙塔西奥奶酪的特色。