高糖胁迫对酿酒酵母抗氧化活性及代谢的影响

Effect of High-glucose Condition on Antioxidant Activity and Metabolism of Saccharomy cescerevisiae

本文以酿酒酵母(Saccharomy cescerevisiae)为模式生物,研究了高糖培养条件对酿酒酵母的生长、抗氧化酶活性及海藻糖、甘油代谢的影响。结果表明:当葡萄糖浓度达到40%时,酿酒酵母生长的对数期延长,对酿酒酵母的生长产生了抑制作用。酿酒酵母在培养4~10 h范围内四组酿酒酵母细胞(20 g/L葡萄糖组、40 g/L葡萄糖组、60 g/L葡萄糖组和80 g/L葡萄糖组)内海藻糖的积累随着胁迫时间的增加发生显著变化(P<0.05),海藻糖的积累量呈先升高后下降的趋势,在8 h时高糖组海藻糖积累量均达到一个最高点,胞内海藻糖的浓度最高达到0.0955 mg/mL。在不同葡萄糖浓度胁迫下,酵母细胞胞内外甘油的积累随着时间增加呈现出先上升后下降的趋势,但是胞内甘油的积累量在80 g/L葡萄糖浓度时达到最高,而胞外甘油的积累量在60 g/L葡萄糖浓度时达到最高。这些结果说明在高糖胁迫下甘油和海藻糖是酿酒酵母的主要相容性溶质。另外,高糖处理后,与对照组相比,高糖组酿酒酵母胞内超氧化物歧化酶(Superoxide Dismutase,SOD)、过氧化氢酶(Catalase,CAT)和谷胱甘肽过氧化物酶(GSH-Px)活性均显著升高(P<0.05),说明这些抗氧化物酶活性物质对维持有机体胞内正常渗透压起到关键作用。该研究结果将为今后研究酿酒酵母耐高糖渗透压方面提供理论依据。

In this paper,Saccharomyces cerevisiae was used as model organism to study the effects of high glucose culture on the growth,antioxidant enzyme activities andtrehalose and glycerol metabolism of Saccharomyces cerevisiae.The results showed that,when the glucose concentration reached 40%,the logarithmic phase of S.cerevisiae growth was prolonged,which inhibited the growth of S.cerevisiae.The accumulation of trehalose showed significant changes with the increasing of stress time(P<0.05),the accumulation of trehalose increased first and then decreased in the four groups of Saccharomyces cerevisiae cells(20 g/L glucose group,40 g/L glucose group,60 g/L glucose group and 80 g/L glucose group)in the range of 4~10 h culture.The accumulation of trehalose in the high sugar group reached a highest point with 95.5 mg/mL intracellular trehalose at 8 h culture.Under the stress of different glucose concentrations,the accumulation of glycerol in yeast cells increased first and then decreased with time up,but the accumulation of intracellular glycerol reached the highest at 80 g/L glucose,while the accumulation of extracellular glycerol reached the highest at 60 g/L glucose.These results indicated that glycerol and trehalose were the main compatible solutes of S.cerevisiae under high sugar stress.In addition,after high glucose treatment,S.cerevisiae superoxide of dismutase(SOD),catalase(CAT)and glutathione peroxidase with high glucose group were significant higher than the control group.It indicated that these antioxidant enzymes play a key role in maintaining the intracellular normal osmotic pressure.The results of this study would provide a theoretical basis for the future study of S.cerevisiae resistance to high glucose osmotic pressure.