Windholtz Sara, Vinsonneau Emmanuel, Farris Laura, Thibon Cécile, Masneuf-Pomarède Isabelle
Univ. Bordeaux, INRAE, Bordeaux INP, UR OENOLOGIE, EA 4577, USC 1366, ISVV, Villenave d'Ornon, France.
Institut Français de la Vigne et du Vin, Blanquefort, France.
Front Microbiol. 2021 Dec 24;12:748416. doi: 10.3389/fmicb.2021.748416. eCollection 2021.
Changes are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO)] 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 SO. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO. 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, which was lower at advanced maturity, while vintage had a strong impact on spp. population level and abundance. The presence of SO altered the abundance of yeast and filamentous fungi, but not their nature. The absence of sulfiting led to an unexpected reduction in diversity compared to the presence of SO, which might result from the occupation of the niche by certain dominant species, namely spp. Inoculation of the grape juice with non- yeast resulted in a decrease in the abundance of filamentous fungi generally associated with a decline in grape must quality. Lower abundance and niche occupation by bioprotection agents were observed at the overripened stage, thus suggesting that doses applied should be reconsidered at advanced maturity. Our study confirmed the bioprotective role of and in a context of vinification without sulfites.
目前正在对酿酒工艺进行改进，以减少化学物质的投入（特别是二氧化硫）并适应消费者需求。在本研究中，对梅洛葡萄酒在不添加二氧化硫的酿酒前期阶段的酵母生长和真菌多样性进行了调查。在一项为期两年的研究中考虑了不同因素：年份、成熟度水平以及添加酵母作为二氧化硫替代品的生物保护作用。通过定量PCR监测目标物种的数量，并通过18S rDNA宏条形码技术确定酵母和丝状真菌的多样性。浸提过程中α多样性逐渐降低这一现象被凸显出来。成熟度水平对酵母和真菌的丰度起着重要作用，在成熟后期丰度较低，而年份对特定物种的种群水平和丰度有很大影响。二氧化硫的存在改变了酵母和丝状真菌的丰度，但没有改变它们的种类。与存在二氧化硫相比，不进行亚硫酸盐处理导致多样性意外降低，这可能是由于某些优势物种（即特定物种）占据了生态位所致。用非酿酒酵母接种葡萄汁导致丝状真菌丰度降低，这通常与葡萄汁质量下降有关。在过熟阶段观察到生物保护剂的丰度较低且存在生态位占据现象，因此表明在成熟后期应重新考虑使用剂量。我们的研究证实了在无亚硫酸盐酿酒环境中特定酵母和酿酒酵母的生物保护作用。
