盐胁迫对鲁氏酵母菌生理特性的影响

研究了盐胁迫对鲁氏酵母菌(Zygosaccharomyces rouxii CGMCC 3791)细胞生理特性的影响,结果表明,盐胁迫使细胞生长受到抑制,单位(每克)菌体乙醇含量从11.64mg增加到19.20mg(120g/L NaCl)。分析细胞胞内pH值和胞内活性氧(ROS)水平,结果表明:盐胁迫使细胞胞内pH值水平降低,胞内活性氧(ROS)水平增加,同时胞内抗氧化酶系(过氧化氢酶、超氧化物歧化酶、过氧化物酶,以及谷胱甘肽过氧化物酶)的活力提高,从而抵御由盐胁迫引起的氧胁迫。研究了盐胁迫对鲁氏酵母菌胞内谷胱甘肽(GSH)含量的影响,结果表明,随着盐质量浓度增加,胞内GSH含量增加,在120g/L盐质量浓度下,GSH含量显著增加了73.4%。考察了外源添加GSH对细胞生长的影响,发现添加0.5g/L GSH的鲁氏酵母菌,在120g/L盐质量浓度下生物量提高了15%。本研究可对深入认识鲁氏酵母菌耐盐生理机制及进一步提高其耐盐性能提供理论支持。

Effect of Salt Stress on Physiological Characterization of Zygosacchromyces rouxii

The effects of salt stress on the physiological characterization of Zygosaccharomyces rouxii CGMCC 3791 were studied, the results showed that salt stress inhibited cell growth and the ethanol content increased from 11.64mg to 19.20mg (120g/L NaCl). Analysis of intracellular pH and reactive oxygen species (ROS) levels showed that salt stress led to the decrease in intracellular pH and increase in ROS level. Meanwhile, the activities of intracellular antioxidant enzymes (catalase, superoxide dismutase, peroxidase and glutathione peroxidase) were increased to resist oxygen stress induced by salt stress. The effect of salt stress on the intracellular glutathione (GSH) content of Z. rouxii was measured, and the results showed that the intracellular GSH content increased with the increase of salt concentration. At 120g/L salt concentration, the GSH content increased significantly by 73.4%. Then the effect of exogenous addition of glutathione on cell growth was investigated, and the results showed that the biomass of cells increased by 15% at 120g/L salt concentration by adding 0.5g/L glutathione. This study may provide theoretical support for in-deep understanding the salt-tolerant physiological mechanisms of Z. rouxii and further improvement of its salt tolerance.