Accelerated Alcoholic Fermentation of Intact Grapes by Saccharomyces Cerevisiae in Symbiosis with Microbial Community Inhabiting Grape-skin

Abstract

Saccharomyces cerevisiae, an essential player in alcoholic fermentation during winemaking, is rarely found in intact grapes. Here, we addressed symbiotic interactions between S. cerevisiae and grape-skin residents upon spontaneous wine fermentation. When glucose was used as a carbon source, the yeast-like fungus Aureobasidium pullulans, a major grape-skin resident, had no effect on alcoholic fermentation by S. cerevisiae. In contrast, when intact grape berries as a sole carbon source, coculture of S. cerevisiae and A. pullulans accelerated alcoholic fermentation. Thus, grape-inhabiting microorganisms may increase carbon availability by degrading and/or incorporating grape-skin materials, such as cell wall and cuticles. A. pullulans exhibited broad spectrum assimilation of plant-derived carbon sources, including ω-hydroxy fatty acids, arising from degradation of cutin. In fact, yeast-type cutinase was produced from A. pullulans EXF-150 strain. The degradation and utilization of grape-skin materials by fungal microbiota may account for their colonization on grape-skin and symbiotic interactions with S. cerevisiae.

Non-Saccharomyces Yeast Strains, Aromatic Compounds and Sensory Analysis of Italy and Negra Criolla Pisco from the Moquegua Region of Peru

“…It has been isolated from different grape cultivars that have suffered physical damage [41] and can be used as an effective biocontrol agent in agriculture against several of the major post-harvest pathogens [42]. However, A. pullulans has been recognized as a major grape-skin resident that in co-culture with S. cerevisiae can accelerate alcoholic fermentation [43]. A plausible explanation of this is the polygalacturonase activity observed in A. pullulans [44], which could increase carbon availability from grape-skin materials such as the cell wall and cuticles [43], thereby improving the color and reducing filtration time and turbidity [34].…”

“…However, A. pullulans has been recognized as a major grape-skin resident that in co-culture with S. cerevisiae can accelerate alcoholic fermentation [43]. A plausible explanation of this is the polygalacturonase activity observed in A. pullulans [44], which could increase carbon availability from grape-skin materials such as the cell wall and cuticles [43], thereby improving the color and reducing filtration time and turbidity [34]. The enzymatic activity of A. pullulans was very high, compared to other NSYSs isolated from I and NC grape varieties, including M. pulcherrima (Figure 1C).…”