0000000000327919
AUTHOR
Ying Su
Nitrogen Metabolism of Saccharomyces and Non-Saccharomyces Wine Strains: Phenotypic and Genomic Characterisation
S. cerevisiae is the most important yeast species for winemaking. In our study, different approaches were applied to evaluate the nitrogen requirement of a set of commercial S. cerevisiae strains. The selected high and low nitrogen demanding strains were sequenced and genomic differences were compared. Allele swapping of GCN1 gene revealed that the polymorphism of this gene is not the main reason for the nitrogen requirement differences in our strains. The cryotolerante Saccharomyces species such as S. uvarum, S. eubayanus and S. kudriavzevii are becoming more and more popular for wine making. However, the nitrogen requirements of these species is unclear. We studied the fermentation behavi…
Interspecific hybridisation among diverse Saccharomyces species: A combined biotechnological solution for low-temperature and nitrogen-limited wine fermentations
Lack of the prezygotic barrier in the Saccharomyces genus facilitates the construction of artificial interspecific hybrids among different Saccharomyces species. Hybrids that maintain the interesting features of parental strains have been applied in industry for many beneficial purposes. Two of the most important problems faced by wine makers is nitrogen deficiency in grape must and low-temperature fermentation. In our study, hybrids were constructed by using selected low nitrogen-demanding cryotolerant S. eubayanus, S. uvarum strains and S. cerevisiae. The fermentation capacity of the hybrid strains was tested under four conditions by combining two temperatures, 12 °C and 28 °C, and two ni…
Impact of Nitrogen Addition on Wine Fermentation by S. cerevisiae Strains with Different Nitrogen Requirements
In modern oenology, supplementation of nitrogen sources is an important strategy to prevent sluggish or stuck fermentation. The present study thoroughly determined the effect of nitrogen addition timing and nitrogen source type on fermentation kinetics and aroma production, carried out by yeast strains with low and high nitrogen requirements. The results revealed that yeast strains with different nitrogen requirements have divergent reactions to nitrogen addition. Nitrogen addition clearly shortened the fermentation duration, especially for the high-nitrogen-demanding yeast strain. Nitrogen addition at 1/3 fermentation was the most effective in terms of fermentation activity, nitrogen assim…