Starmerella bacillaris and Saccharomyces cerevisiae mixed fermentations to reduce ethanol content in wine

Abstract

Decreasing the ethanol content in wine is a current challenge, mainly due to the global climate change and to the consumer preference for wines from grapes with increased maturity. In this study, a central composite design (CCD) and response surface methodology (RSM) approach was used to investigate the potential application of Starmerella bacillaris (synonym Candida zemplinina) in combination with Saccharomyces cerevisiae, in mixed (co-inoculated and sequential) cultures, to understand better the mechanism of co-habitation and achieve the objective of reducing the ethanol in wines. Laboratory scale fermentations demonstrated a decrease up to 0.7 % (v/v) of ethanol and an increase of about 4.2 g/L of glycerol when S. cerevisiae was inoculated with a delay of 48 h with respect to the inoculation of S. bacillaris. Pilot-scale fermentations, carried out in winemaking conditions, confirmed the laboratory results. This study demonstrates that the combination of strains and inoculation protocol could help to reduce the ethanol content in wines.

Draft Genome Sequence of the Yeast Starmerella bacillaris (syn., Candida zemplinina ) FRI751 Isolated from Fermenting Must of Dried Raboso Grapes

“…Unable to grow in vitamin-free medium, it develops well in the presence of high glucose concentration, up to 50% (wt/vol) (6). It is highly fructophilic and a high-glycerol producer (7). …”

“…In particular, it produces less ethanol from must fermentation than Saccharomyces cerevisiae , low levels of biogenic amines, and average volatile acidity (8). It is also being tested in association with Saccharomyces cerevisiae in mixed or sequential fermentations to reduce alcohol content and to increase the organoleptic properties of wines (7), and its possible use in the vineyard as an antifungal agent against Botrytis is under study (8). …”

Challenges of the Non-Conventional Yeast Wickerhamomyces anomalus in Winemaking

“…Nowadays, the role of non-Saccharomyces has been re-evaluated, and it is widely accepted that selected strains can positively influence the winemaking process [2]. Beyond the contribution of non-Saccharomyces yeasts to wine aroma complexity [3], these yeasts can help address some of the modern challenges in winemaking, including the reduction of the ethanol content of wine [4][5][6][7] or the control of wine spoilage [8,9].…”

Evaluation of different co-inoculation time of non-Saccharomyces/Saccharomycesyeasts in order to obtain reduced ethanol wines

“…The use of non-Saccharomyces starters together with Saccharomyces cerevisiae in grape must fermentations has been investigated for more than 20 years [13][14][15][16][17] In this way, these studies have demonstrated that using non-Saccharomyces-S. cerevisiae yeasts represent a feasible way towards improving wine complexity and enhancing particular and specific characteristics of a wine [18] Therefore, these co-inoculation strategies provide better results than fermentations only inoculated with S. cerevisiae.…”

“…Furthermore, these co-inocula under mixed conditions showed similar efficiency conversion than S. cerevisiae control ( Table 2). Several authors reported that a reduction in the alcohol level was achieved in fermentations using sequential inoculations [18][19][20][21]. In turn, these sequential inoculations showed better results when delay timing between non-Saccharomyces and S. cerevisiae yeasts was higher.…”