Abstract：
BACKGROUND: Saccharomyces cerevisiae is susceptible to high-sugar stress in the production of bioethanol, wine and bread. Calcium signal is widely involved in various physiological and metabolic activities of cells. The present study aimed to explore the effects of Ca2+ signal on the antioxidant mechanism of yeast during high-sugar fermentation.
RESULTS: Compared to yeast without available Ca2+, yeast in the high glucose with Ca2+ group had higher dry weight, higher ethanol output at 12 and 24 h and higher glycerol output at 24 and 36 h. During the whole growth process, the trehalose synthesis capacity of yeast in the high glucose with Ca2+ group was lower and intracellular reactive oxygen species content was higher compared to yeast without available Ca2+. Intracellular malondialdehyde content of yeast under high glucose with Ca2+ was significantly lower than yeast under high glucose without available Ca2+ except for 6 h. The superoxide dismutase and catalase activities of yeast and glutathione content were higher in the high glucose with Ca2+ group compared to yeast in high glucose without available Ca2+. The expression levels of SOD1, GSH1, GPX2 genes were higher for high glucose without available Ca2+ at 6 h, while yeast in the high glucose with Ca2+ group had a higher expression of antioxidant-related genes except SOD1 and CTT1 at 12 h. The expression levels of antioxidant-related genes of yeast for high glucose with Ca2+ were higher at 24 h, and those of genes except SOD1 of yeast in the high glucose with Ca2+ group were higher at 36 h.
CONCLUSIONS: High-glucose stress limited the growth of yeast, while a moderate extracellular Ca2+ signal could improve the antioxidant capacity of yeast in a high-glucose environment by regulating protectant metabolism and enhancing the antioxidant enzyme activity and expression of antioxidant genes in a high-sugar environment. © 2024 Society of Chemical Industry.
RESULTS: Compared to yeast without available Ca2+, yeast in the high glucose with Ca2+ group had higher dry weight, higher ethanol output at 12 and 24 h and higher glycerol output at 24 and 36 h. During the whole growth process, the trehalose synthesis capacity of yeast in the high glucose with Ca2+ group was lower and intracellular reactive oxygen species content was higher compared to yeast without available Ca2+. Intracellular malondialdehyde content of yeast under high glucose with Ca2+ was significantly lower than yeast under high glucose without available Ca2+ except for 6 h. The superoxide dismutase and catalase activities of yeast and glutathione content were higher in the high glucose with Ca2+ group compared to yeast in high glucose without available Ca2+. The expression levels of SOD1, GSH1, GPX2 genes were higher for high glucose without available Ca2+ at 6 h, while yeast in the high glucose with Ca2+ group had a higher expression of antioxidant-related genes except SOD1 and CTT1 at 12 h. The expression levels of antioxidant-related genes of yeast for high glucose with Ca2+ were higher at 24 h, and those of genes except SOD1 of yeast in the high glucose with Ca2+ group were higher at 36 h.
CONCLUSIONS: High-glucose stress limited the growth of yeast, while a moderate extracellular Ca2+ signal could improve the antioxidant capacity of yeast in a high-glucose environment by regulating protectant metabolism and enhancing the antioxidant enzyme activity and expression of antioxidant genes in a high-sugar environment. © 2024 Society of Chemical Industry.
摘要：
背景：酿酒酵母在生产生物乙醇时容易受到高糖胁迫，葡萄酒和面包钙信号广泛参与细胞的各种生理和代谢活动。本研究旨在探讨Ca2+信号对酵母高糖发酵过程中抗氧化机制的影响。
结果：与没有可用Ca2+的酵母相比，高糖加Ca2+组酵母干重较高,更高的乙醇产量在12和24小时和更高的甘油产量在24和36小时。与不含有效Ca2+的酵母相比，含Ca2+的高糖酵母的海藻糖合成能力较低，细胞内活性氧含量较高。含Ca2+高糖条件下酵母胞内丙二醛含量除6h外显著低于无有效Ca2+高糖条件下酵母的胞内丙二醛含量。SOD1，GSH1，GPX2基因的表达水平在6h高糖无可用Ca2+时更高，而高糖加Ca2组的酵母在12h时除SOD1和CTT1外，抗氧化相关基因的表达水平较高。高糖Ca2组酵母除SOD1外的基因在36h时均较高。
结论：高糖胁迫限制了酵母的生长，而适度的细胞外Ca2+信号可以通过调节高糖环境中的保护剂代谢、增强抗氧化酶活性和抗氧化基因的表达来提高酵母在高糖环境中的抗氧化能力。©2024化学工业学会。
结果：与没有可用Ca2+的酵母相比，高糖加Ca2+组酵母干重较高,更高的乙醇产量在12和24小时和更高的甘油产量在24和36小时。与不含有效Ca2+的酵母相比，含Ca2+的高糖酵母的海藻糖合成能力较低，细胞内活性氧含量较高。含Ca2+高糖条件下酵母胞内丙二醛含量除6h外显著低于无有效Ca2+高糖条件下酵母的胞内丙二醛含量。SOD1，GSH1，GPX2基因的表达水平在6h高糖无可用Ca2+时更高，而高糖加Ca2组的酵母在12h时除SOD1和CTT1外，抗氧化相关基因的表达水平较高。高糖Ca2组酵母除SOD1外的基因在36h时均较高。
结论：高糖胁迫限制了酵母的生长，而适度的细胞外Ca2+信号可以通过调节高糖环境中的保护剂代谢、增强抗氧化酶活性和抗氧化基因的表达来提高酵母在高糖环境中的抗氧化能力。©2024化学工业学会。
