Multi-omic characterization of microbial dynamics during spontaneous fermentation of Picolit varieties
Spontaneous wine fermentation is driven by the ecological succession of vineyard-derived microorganisms, yet little is known about how this process unfolds in Picolit, a grape variety characterized by acinellatura (berry millerandage) and elevated sugar concentration. Here, we applied an integrated multi-omic approach to characterize the microbial and metabolic dynamics of spontaneous Picolit fermentation from Aquila del Torre, an organic and biodynamic winery in Savorgnano del Torre (Friuli-Venezia Giulia, Italy), part of the newly established “Friuli Colli Orientali Sottozona Savorgnano D.O.C.”. Shotgun metagenomics and untargeted metabolomics were performed across five fermentation stages. The initial must display high microbial richness dominated by non-Saccharomyces yeasts, oxidative bacteria and Botrytis cinerea. An atypical persistence and increasing abundance of B. cinerea suggested a strong interaction between grape physiology and fungal activity. Early fermentation was shaped by diverse non-Saccharomyces taxa (Lachancea, Pichia, Torulaspora, Schizosaccharomyces), which contributed to acid modulation, aromatic precursor release and phenolic turnover. From mid-fermentation onward, a multi-species Saccharomyces consortium established functional dominance, coinciding with a collapse of bacterial diversity and a metabolic shift from aromatic-degradation pathways to stress-adaptation functions. Multi-omic networks revealed a progressive loss of modularity as fermentation stabilized. Overall, Picolit fermentation exhibits a distinctive microbial and functional signature influenced by terroir, grape physiology and native microbial diversity, supporting the enological value of spontaneous fermentation for the Savorgnano Bianco D.O.C.
Spontaneous wine fermentation is driven by the ecological succession of vineyard-derived microorganisms, yet little is known about how this process unfolds in Picolit, a grape variety characterized by acinellatura (berry millerandage) and elevated sugar concentration. Here, we applied an integrated multi-omic approach to characterize the microbial and metabolic dynamics of spontaneous Picolit fermentation from Aquila del Torre, an organic and biodynamic winery in Savorgnano del Torre (Friuli-Venezia Giulia, Italy), part of the newly established “Friuli Colli Orientali Sottozona Savorgnano D.O.C.”. Shotgun metagenomics and untargeted metabolomics were performed across five fermentation stages. The initial must display high microbial richness dominated by non-Saccharomyces yeasts, oxidative bacteria and Botrytis cinerea. An atypical persistence and increasing abundance of B. cinerea suggested a strong interaction between grape physiology and fungal activity. Early fermentation was shaped by diverse non-Saccharomyces taxa (Lachancea, Pichia, Torulaspora, Schizosaccharomyces), which contributed to acid modulation, aromatic precursor release and phenolic turnover. From mid-fermentation onward, a multi-species Saccharomyces consortium established functional dominance, coinciding with a collapse of bacterial diversity and a metabolic shift from aromatic-degradation pathways to stress-adaptation functions. Multi-omic networks revealed a progressive loss of modularity as fermentation stabilized. Overall, Picolit fermentation exhibits a distinctive microbial and functional signature influenced by terroir, grape physiology and native microbial diversity, supporting the enological value of spontaneous fermentation for the Savorgnano Bianco D.O.C.
Universita degli studi di Milano