This work is to explore the metabolic mechanism of Saccharomyces cerevisiae and the change of the cell membrane function while adding different concentrations of Ca2+ under different pH.Using S.cerevisiae as research target,the metabolic characteristics of yeast cells were studied by adjusting pH and the concentration of Ca2+ in model grape juice medium,and also the metabolic mechanisms were investigated from the perspective of permeability and integrity of the cell membrane.The fermentation was conducted under the condition of temperature was 28℃,rotation speed was 120 r/min,and inoculation was 1 × 106 mol/L.Results showed that the rate of metabolism was accelerated,and the permeability and integrity of cell membrane were enhanced with the increase of Ca2+ concentration when the pH was 3.0,indicating that the inhibiting effect caused by low pH was eliminated after adding Ca2+.The effect of Ca2+ addition was not significant when the pH was 5.5.The above results indicated that Ca2+ alleviated the physiologically toxic effects of low pH on S.cerevisiae.%为了探究不同pH下添加不同浓度的Ca2+对酿酒酵母的代谢机制以及细胞膜功能的影响,以酿酒酵母为研究对象,利用模拟葡萄汁培养基,通过调整培养基中pH值和Ca2+含量,研究了酵母菌的代谢特征,并从细胞膜通透性和完整性的角度考察酵母代谢的机制.在确定的发酵条件下进行发酵:温度为28℃、转速为120 r/min,接种量为1×106 mol/L.结果表明,当pH为3.0时,随着Ca2+浓度的增加,酵母菌代谢速率加快,酵母菌细胞膜的通透性和完整性也增强,即Ca2+的添加减弱低pH对酵母的抑制作用.而当pH为5.5时,Ca2+对酵母菌代谢速率以及细胞膜的通透性和完整性作用不明显.结果表明Ca2+能缓解低pH下酿酒酵母的生理毒害作用.
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