Traditional type I sourdoughs are being rediscovered and increasingly used in artisanal and industrial bakeries due to the unique taste and texture, potential health benefits, and longer shelf life they confer on to baked products. These unique properties are attributed to the diverse microbial communities of sourdough, comprising both yeasts and bacteria. The traditional preservation method for type I sourdough (i.e., continuous backslopping) may lead, over time, to taxonomic and functional rearrangements of its microbial communities. Consequently, significant deviations in the characteristics of baked products can occur. In this context, this review aims to summarize the recent literature on the long-term preservation and maintenance strategies for type I sourdough and highlight the essential role that microbial biological resource centers (mBRCs) could play in the preservation and sharing of sourdough microbiomes. Specifically, the identification of appropriate preservation methods, implementation of well-defined access and benefit-sharing protocols, and development of microbiome-specific datasets, should be encouraged within the context of mBRCs. These infrastructures are expected to play a pivotal role in preserving the microbiota of fermented foods, serving as a crucial element for innovation and the safeguarding of traditional foods and culinary heritage.

Extracts from locally grown aromatic plants can enhance the geographical characteristics and microbial stability of craft beers, which are often not pasteurized or filtered. Here, the chemical and antimicrobial properties of aqueous extracts from leaves of Myrtus communis L., Pistacia lentiscus L., Artemisia arborescens L., and floral wastes of Crocus sativus L., all cultivated in Sardinia (Italy), were assessed. P. lentiscus extract had the highest polyphenol content (111.20 mg GAE/g), followed by M. communis (56.80 mg GAE/g), C. sativus (32.80 mg GAE/g), and A. arborescens (8.80 mg GAE/g). Notably, only the M. communis extract demonstrated significant inhibitory activity against pathogenic and spoilage microorganisms, with minimum inhibitory concentrations of 0.18, 0.71, and 1.42 mg GAE/mL against Staphylococcus aureus, Lactiplantibacillus plantarum, and Lacticaseibacillus casei, respectively. Additionally, it reduced the growth of Levilactobacillus brevis and Fructilactobacillus lindneri at concentrations of 0.35 and 0.71 mg GAE/mL, respectively. Based on its significant antimicrobial activity, the M. communis extract was further characterized using high-resolution mass spectrometry, revealing high abundances of nonprenylated phloroglucinols, flavonoid derivatives (myricetin), and quinic acids. Lastly, adding M. communis extract (2.84 mg GAE/mL) to commercial beer effectively prevented the growth of L. brevis and F. lindneri, showing its potential to avoid beer’s microbial spoilage.

Sourdoughs are complex microbial ecosystems fundamental to traditional breadmaking. Despite extensive research, variability among traditional sourdough ecosystems remains a key area of investigation. In this context, 13 type I sourdough starters from Villaurbana (Sardinia, Italy) were characterised combining molecular and biochemical techniques. Bacterial and fungal communities were identified by NGS-based amplicon sequencing, while lactic and acetic acid, and residual sugars were quantified. The bacterial population was dominated by the genus Fructilactobacillus, whereas the fungal community spanned multiple genera. To explore the mycobiota, 130 yeast isolates were identified sequencing D1–D2 domain and through MALDI-TOF mass spectrometry. Six yeast species were detected: Saccharomyces cerevisiae was the dominant species (58.46%), followed by non-Saccharomyces yeasts (41.54%), including Torulaspora delbrueckii, Pichia fermentans, Wickerhamomyces anomalus, Maudiozyma humilis, and Monosporozyma unispora. Strain-level typing via microsatellite analysis revealed high intraspecific diversity among S. cerevisiae and T. delbrueckii isolates. S. cerevisiae strains were distributed across distinct genetic lineages, with some clustering alongside industrial reference strains and others displaying unique evolutionary trajectories. T. delbrueckii strains formed two clonal groups substantially divergent from reference strains. This study supports the restitution of characterized yeast strains to the community as a resource for establishing a new microbial consortium representative of Villaurbana sourdough tradition.