Selection of non-Saccharomyces yeasts to be used in grape musts with high alcoholic potential: a strategy to obtain wines with reduced ethanol content

Abstract

Ethanol content of wine has increased over the last decades as consequence of searching phenolic maturity, requiring increased grape maturity. This may result in the production of wines with excessive alcohol levels (sometimes more than 15% (v/v)), sluggish and stuck fermentations and excessive volatile acidity. Many strategies to reduce ethanol in wines are being studied, and microbial methods have some additional advantages. However, because of the broad intra- and interspecies variability, new selection criteria should be included. Therefore, the goal of the present work was to design and evaluate a simple and integral procedure for non-Saccharomyces yeast selection. This strategy allowed selection of yeasts that presented successful implantation in grape must with high alcohol potential and their use in co-cultures could reduce the ethanol in wines. A total of 114 native non-Saccharomyces yeasts were assayed to determine their respiratory, fermentative and physiological characteristics of enological interest. Hanseniaspora uvarum BHu9 and BHu11, H. osmophila BHo51, Starmerella bacillaris BSb55 and Candida membranaefaciens BCm71 were selected as candidates to design co-culture starters.

Molecular and Phenotypic Characterization of Metschnikowia pulcherrima Strains from Douro Wine Region

“…In this study, all isolates of M. pulcherrima were able to grow under the maximum level of H 2 O 2 tested (Figure 2 and Table S1). Our results are consistent with those found by Furlani et al [16] that evaluated H 2 O 2 tolerance in this and other non-Saccharomyces species. The authors suggested that this feature could be associated with the catalase activity expressed by these yeasts.…”

Impact on Sensory and Aromatic Profile of Low Ethanol Malbec Wines Fermented by Sequential Culture of Hanseniaspora uvarum and Saccharomyces cerevisiae Native Yeasts

“…It is well known that H. uvarum is the most representative yeast species found on grape surfaces showing prevalence during early stages of spontaneous alcoholic fermentation [32]. This yeast has several characteristics that could be used to reduce ethanol content in wines [21]. In the current study, inoculation of H. uvarum BHu9 prior to inoculation of S. cerevisiae BSc114 demonstrated a sugar consumption of 35.7 g/L for 1% of ethanol produced.…”

“…In addition to the aforementioned effects, this yeast group is also known to be less efficient in the production of ethanol from consumed sugars when compared with S. cerevisiae yeasts [19].Hanseniaspora genera as a whole and particularly Hanseniaspora uvarum species are non-Saccharomyces yeasts commonly encountered at high concentrations on the grape surface and throughout the fermentation process [20]. Recently, 28 H. uvarum isolates were evaluated by our research group and they demonstrated interesting enological characteristics such us: ability to grow at high sugar, ethanol and SO 2 contents; to produce high concentrations of glycerol; low acetic acid and hydrogen sulfide levels; and the release of proteolytic enzymes [21]. Moreover, it is important to highlight that H. uvarum was also found to be a potential candidate to produce less ethanol because it requires more than 19 g/L of consumed sugar to produce 1% v/v of ethanol [21].…”

“…Recently, 28 H. uvarum isolates were evaluated by our research group and they demonstrated interesting enological characteristics such us: ability to grow at high sugar, ethanol and SO 2 contents; to produce high concentrations of glycerol; low acetic acid and hydrogen sulfide levels; and the release of proteolytic enzymes [21]. Moreover, it is important to highlight that H. uvarum was also found to be a potential candidate to produce less ethanol because it requires more than 19 g/L of consumed sugar to produce 1% v/v of ethanol [21]. In a more recent study, a selected H. uvarum yeast strain was assessed in sequential inoculations with S. cerevisiae yeasts under optimized fermentation conditions [22].…”

“…">MicroorganismsHanseniaspora uvarum BHu9 and Saccharomyces cerevisiae BSc114 were used in the present study. Both strains of yeasts were previously selected based on their oxidative and fermentative metabolism in order to obtain reduced ethanol wines [21]. Strains were obtained from the Culture Collection of Autochthonous Microorganisms (Institute of Biotechnology, School of Engineering-UNSJ, San Juan, Argentina) and preserved at −80 • C until use.…”