Time filter

Source Type

Li J.,Qingdao Agricultural University | Zhao H.,China Agricultural University | Huang W.,China Agricultural University | Huang W.,Center for Research and Development of Viticulture and Enology | Huang W.,Beijing Key Laboratory of Viticulture and Enology
Journal of Industrial Microbiology and Biotechnology

Our previous work revealed proanthocyanidins (PAs) could pose significant enhancement on the activity of H+-ATPase and fermentation efficiency after a transient initial inhibition (Li et al in Am J Enol Vitic 62(4):512–518, 2011). The aim of the present work was to understand the possible mechanism for this regulation. At Day 0.5 the gene expression level of PMA1 in AWRI R2 strain supplemented with 1.0 mg/mL PAs was decreased by around 54 % with a 50 % and a 56.5 % increase in the concentration of intracellular ATP and NADH/NAD+ ratio, respectively, compared to that of control. After the transient adaptation, the gene expression levels of PMA1 and HXT7 in PAs-treated cells were enhanced significantly accompanied by the decrease of ATP contents and NADH/NAD+ ratio, which resulted in the high level of the activities of rate-limiting enzymes. PAs could pose significant effects on the fermentation via glucose transport, the energy and redox homeostasis as well as the activities of rate-limiting enzymes in glycolysis. © 2014, Society for Industrial Microbiology and Biotechnology. Source

Li J.-Y.,Qingdao Agricultural University | Li J.-Y.,China Agricultural University | Zhao H.-W.,China Agricultural University | Huang W.-D.,China Agricultural University | And 2 more authors.
Australian Journal of Grape and Wine Research

Background and Aims: Proanthocyanidins (PAs), the predominant phenolic substances in wine, are responsible for the astringency of wine. The present work aims to understand the effect of yeast on the concentration and composition of the subunits of PAs during fermentation. Methods and Results: The concentration and cleavage products (subunits) of PAs were measured during fermentation. Early in fermentation (within about 4 days), the concentration of PAs decreased significantly by around 78% for strain BH8 and 67% for strain AWRI R2; in addition, the mean degree of polymerisation and composition of PAs underwent considerable change. At the later phase of fermentation, no significant change was recorded in the concentration and mean degree of polymerisation of PAs, whereas the composition of PAs evolved progressively. Conclusions: Yeast can exert a significant influence on the concentration and structure of PAs during wine fermentation in a strain- and time-dependent manner. Significance of the Study: The results will enable a better understanding of the effect of yeast on the evolution of PAs in winemaking, as well as increase knowledge of the interaction between yeasts and phenolic substances to improve wine composition. © 2015 Australian Society of Viticulture and Oenology Inc. Source

Li J.-Y.,China Agricultural University | Li J.-Y.,Center for Research and Development of Viticulture and Enology | Du G.,China Agricultural University | Yang X.,China Agricultural University | And 2 more authors.
American Journal of Enology and Viticulture

Proanthocyanidins are extracted from grapes during red wine fermentation. The aim of this study was to understand the effect of proanthocyanidins on yeast metabolism, plasma membrane H +-ATPase, and wine fermentation. Two strains of Saccharomyces cerevisiae (industrial strain AWRI R2 and newly selected strain BH8) and a simple model fermentation system containing different concentrations of proanthocyanidins were used. The proanthocyanidins inhibited the activity of H +-ATPase during the initial phase of the fermentation, parallel to a decrease in cell growth, CO 2 release, sugar consumption, and ethanol production. However, proanthocyanidins increased in the metabolism of cells and the activity of plasma membrane H +-ATPase at the mid-exponential phase. The period of fermentation was shortened by adding proanthocyanidins. In addition, yeast cells preincubated in YPD medium containing proanthocyanidins before inoculation in fermentation medium exhibited weaker inhibition during the initial phase of the fermentation, which may be among the mechanisms of the adaptive response to proanthocyanidins in yeasts. Results suggested that fermentation could be controlled by manipulating proanthocyanidin supplementation. © 2011 by the American Society for Enology and Viticulture. Source

Discover hidden collaborations