biostudies-literatureUnknown12Windholtz SChanges are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO₂)] and adapt to consumer demand. In this study, yeast growth and fungal diversity were investigated in merlot during the prefermentary stages of a winemaking process without addition of SO₂. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO₂. The population of the target species was monitored by quantitative-PCR, and yeast and filamentous fungi diversity was determined by 18S rDNA metabarcoding. A gradual decrease of the α-diversity during the maceration process was highlighted. Maturity level played a significant role in yeast and fungal abundance, whiFrontiers in microbiology748416https://www.ebi.ac.uk/biostudies/studies/S-EPMC8740202biostudies-literatureYeast and Filamentous Fungi Microbial Communities in Organic Red Grape Juice: Effect of Vintage, Maturity Stage, SO₂, and Bioprotection.PMC8740202Windholtz SMasneuf-Pomarede IVinsonneau EFarris LThibon CfalseYeast and Filamentous Fungi Microbial Communities in Organic Red Grape Juice: Effect of Vintage, Maturity Stage, SO₂, and Bioprotection.Changes are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO₂)] and adapt to consumer demand. In this study, yeast growth and fungal diversity were investigated in merlot during the prefermentary stages of a winemaking process without addition of SO₂. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO₂. The population of the target species was monitored by quantitative-PCR, and yeast and filamentous fungi diversity was determined by 18S rDNA metabarcoding. A gradual decrease of the α-diversity during the maceration process was highlighted. Maturity level played a significant role in yeast and fungal abundance, whi2021-01-01T00:00:00Z20212025-04-04T14:53:30.87Z2022-02-11T15:05:30.26ZS-EPMC87402023500299810.3389/fmicb.2021.748416