Dynamic study of yeast species and Saccharomyces cerevisiae strains during the spontaneous fermentations of Muscat blanc in Jingyang, China
The evolution of yeast species and Saccharomyces cerevisiae genotypes during spontaneous fermentations of Muscat blanc planted in 1957 in Jingyang region of China was followed in this study. Using a combination of colony morphology on Wallerstein Nutrient (WLN) medium, sequence analysis of the 26S rDNA D1/D2 domain and 5.8S-ITS-RFLP analysis, a total of 686 isolates were identified at the species level. The six species identified were S. cerevisiae, Hanseniaspora uvarum, Hanseniaspora opuntiae, Issatchenkia terricola, Pichia kudriavzevii (Issatchenkia orientalis) and Trichosporon coremiiforme. This is the first report of T. coremiiforme as an inhabitant of grape must. Three new colony morphologies on WLN medium and one new 5.8S-ITS-RFLP profile are described. Species of non-Saccharomyces, predominantly H. opuntiae, were found in early stages of fermentation. Subsequently, S. cerevisiae prevailed followed by large numbers of P. kudriavzevii that dominated at the end of fermentations. Six native genotypes of S. cerevisiae were determined by interdelta sequence analysis. Genotypes III and IV were predominant. As a first step in exploring untapped yeast resources of the region, this study is important for monitoring the yeast ecology in native fermentations and screening indigenous yeasts that will produce wines with regional characteristics.
- "Kloeckera (Hanseniaspora) has been found in late fermentation phases in wine (of 9% alcohol) produced at temperature of 28°C. Their appearance has been attributed to the low final alcohol level of the wine, their higher temperature tolerance (when compared to Saccharomyces cerevisiae) as well as to strain specificity, preadaptation and cross-protection . Two species of Candida (C. "
[Show abstract] [Hide abstract] ABSTRACT: Some wineries, in order to promote the growth of yeasts able to ferment grape musts, traditionally produce wines using the ‘pied de cuve’ method. The aim of the present work was to study the performance of fortified pied de cuve (FPdC) prepared by addition of wine. Two FPdCs were prepared with the addition of wine at 1.5 and 3% (v/v) of ethanol to the musts and allowed to spontaneously ferment. The FPdCs were then added to fresh bulk musts in order to accelerate the spontaneous alcoholic fermentation (AF). Interestingly, several Saccharomyces cerevisiae strains isolated during the pied de cuve preparation were detected at the highest concentration throughout AF. The chemical composition of the wines conformed to commercial regulations. The volatile organic compounds (VOCs) were mainly represented by diethyl succinate and ethyl lactate, as well as by hexanol and isoamyl alcohol. Principal component analysis of the chemical parameters, VOCs and sensory data showed that the use of experimental pied de cuve influenced positively the composition of the final wines. The FPdC had no negative impact on the microbiological and chemical composition of wines, but it affected the diversity of the species S. cerevisiae present during AF and the sensory profile of the final wine. This study provided evidence that FPdC accelerates spontaneous AF and influences the sensory profile of red wines.0Comments 1Citation
- "A high concentration of acetic acid in wine is responsible for the generation of the off-flavours and makes the product unmarketable. Wines prepared by spontaneous fermentation are frequently characterised by high VA concentration due to the proliferation of spoilage yeasts (Wang and Liu 2013). The impact of LAB activity on wine composition was also revealed by the results of the chemical analysis. "
[Show abstract] [Hide abstract] ABSTRACT: In order to select potential indigenous Saccharomyces strains, diversity of indigenous Saccharomyces strains in Shanshan County (Xinjiang, China) was preliminarily analyzed. Twenty-one genotypes were found through interdelta fingerprinting analysis. According to this result, representatives of each genotype were chosen to test the enological criteria. After tests of fermentation characteristics and growth ability, eight strains were finally selected as starters to further fermentation of Merlot must for aroma analysis and sensory evaluation at the same testing conditions, with one commercial strain F15 as control. Each strain of Saccharomyces cerevisiae produced individual volatiles in different concentrations and combinations which significantly influenced resulting wine flavour. Except of LFP522, all indigenous isolates produced more concentration of esters than F15. Higher concentrations of linalool, β-damascenone and citral, associated with S. cerevisiae LFE1809, considerably distinguished this strain from the others. Sensory evaluation present the Merlot wine fermented by LFE1225 isolated from Merlot, had the highest sensory score.0Comments 0Citations
- "The studies on the selection and evaluation of desirable indigenous wine yeast strains have been conducted in many viticulture regions, such as Sicily (Italy), Teramo (Italy), Frontera (Spain) and León (Spain) (A ´ lvarez-Pérez et al. 2012; Carrascosa et al. 2012; Scacco et al. 2012; Suzzi et al. 2012). However, the yeast ecology was only studied in a few vineyards of major viticultural regions in China (Li et al. 2010, 2011; Wang and Liu 2013). Also, there are limited studies on the selection of indigenous wine yeasts and indigenous S. cerevisiae strains feasibility of inoculating the grape must in China (Liang et al. 2013). "