An Exemplary Model Study for Overcoming Stuck Fermentation during Spontaneous Fermentation with the Aid of a Saccharomyces Triple Hybrid

Abstract

Sluggish or stuck fermentations cause significant financial losses for winemakers each year. In order to investigate the reasons for problems during spontaneous fermentation of Riesling must in a well-known German vineyard of the lower Moselle, yeast strains involved in must fermentation were identified during winemaking in the two years 2011 and 2012. Identification of the yeast isolates was performed by applying analyses of the ITS-1-5.8-ITS2 region and restriction fragment analyses of different gene sequences. It revealed that Saccharomyces (S.) bayanus and not Saccharomyces cerevisiae was the main fermenting yeast. Either S. bayanus finished the fermentation or led to stuck fermentation. After about four weeks of stuck, fermentation continued spontaneously S. bayanus was replaced by the triple hybrid S. cerevisiae × S. kudriavzevii × S. bayanus. The triple hybrid strain HL 78 was able to utilize fructose more efficiently than S. bayanus strain HL 77. The fructophilic character of the triple hybrid strain correlated with an enhanced uptake of radiolabeled fructose compared to glucose.In contrast to the usual starter culture S. cerevisiae, both isolates, S. bayanus strain HL 77 and the triple hybrid strain HL 78, could grow in the absence of ammonium when amino acids were present. However, the triple hybrid was able to consume glucose and especially fructose at lower amino acid concentrations. Thus, the triple hybrid strain HL 78 was a suitable strain to overcome stuck fermentation without changing the fermentation conditions and the aroma profile desired by the selected winery. It has already been successfully used to restart stuck fermentation. The procedure described here could be a useful approach for wine makers facing problems during spontaneous fermentation. Since the application of genetically modified yeast strains is not allowed for starter culture, based on these studies we suggest the generation of hybrid strains with desired phenotypical features from mother yeasts strains/species of a certain winery and their application in case that during a spontaneous fermentations a sluggish or stuck fermentation is observed.

Wine Phenolic Compounds: Antimicrobial Properties against Yeasts, Lactic Acid and Acetic Acid Bacteria

“…The yeasts Wickerhamomyces anomalus AS1, Saccharomyces bayanus HL 77, Saccharomyces cerevisiae × Saccharomyces kudriavzevii × Saccharomyces HL 78 and Saccharomyces cerevisiae 16.1 have been isolated from local wineries in Germany and characterized as described previously [14][15][16]. Debaryomyces hansenii 525 has been isolated from garden soil [17].…”

Stuck at work? Quantitative proteomics of environmental wine yeast strains reveals the natural mechanism of overcoming stuck fermentation

“…Yeast strains S. bayanus HL 77 and triple hybrid S. cerevisiae × kudriavzevii × bayanus HL 78 used in this work originated from spontaneously fermented Riesling wine must in the winery Heymann‐Löwenstein (Winningen, Germany) of the lower Moselle Region , a commercial strain S. cerevisiae Fermivin® has been used as reference strain…”

“…In this work, we studied the proteome evolution of three oenological yeast strains: a commercial wine yeast strain S. cerevisiae commonly used as a starter culture and two indigenous environmental strains which have been isolated during spontaneous grape must fermentation: S. bayanus HL77 and a newly discovered triple hybrid S. cerevisiae × S. kudriavzevii × S. bayanus HL78 . In our previous work we observed the unique properties of the hybrid strain being able to restart fermentation in naturally fermenting wine must when S. bayanus was incapable of completing the process .…”

“…In this work, we studied the proteome evolution of three oenological yeast strains: a commercial wine yeast strain S. cerevisiae commonly used as a starter culture and two indigenous environmental strains which have been isolated during spontaneous grape must fermentation: S. bayanus HL77 and a newly discovered triple hybrid S. cerevisiae × S. kudriavzevii × S. bayanus HL78 . In our previous work we observed the unique properties of the hybrid strain being able to restart fermentation in naturally fermenting wine must when S. bayanus was incapable of completing the process . In the present study we applied 2D‐DIGE technology for the comparative analysis of soluble proteomes during progressive fermentation in order to gain a better understanding of the molecular mechanisms of yeast adaptation to harsh winemaking conditions which may open the possibility to improve the quality of the end‐products of the fermentation process.…”

Purification and Properties of Yeast Proteases Secreted by Wickerhamomyces anomalus 227 and Metschnikovia pulcherrima 446 during Growth in a White Grape Juice

“…The protease activity might help to gain nitrogen from grape proteins necessary for cell growth, especially considering the surplus of sugar carbon in nitrogen-limited milieus [26,27]. The secreted proteases may also act as a survival tool by degrading cell wall proteins of competitive microorganisms, analogous to its role as a virulence factor in C. albicans.…”