原位预处理甘蔗糖蜜对耐高温酿酒酵母突变株Saccharomyces cerevisiae AQ生产乙醇的影响

【目的】探讨和分析原位预处理糖蜜促进酿酒酵母生长和乙醇生产的原因,开发一条绿色、低成本糖蜜乙醇生产途径。【方法】先在不同温度和初始糖浓度条件下,考察酿酒酵母原始菌株Saccharomyces cerevisiae A及其突变株Saccharomyces cerevisiae AQ的生长和乙醇生产性能差异,再以原位预处理前后糖蜜为发酵底物,测定突变株Saccharomyces cerevisiae AQ在不同培养基中的生长量、出芽率、乙醇产量、胞内超氧化物歧化酶(SOD)、过氧化物酶、细胞质内ATP酶和线粒体内ATP酶活力,研究原位预处理糖蜜对其生理特性的影响。【结果】在高温发酵糖蜜过程中,突变株Saccharomyces cerevisiae AQ较原始菌株Saccharomyces cerevisiae A表现出更好的生长和乙醇发酵稳定性。当以原位预处理糖蜜作为Saccharomyces cerevisiae AQ唯一碳源时,其胞内SOD酶、过氧化物酶、细胞质内ATP酶和线粒体内ATP酶活力较以糖蜜原料为唯一碳源时分别提高2.51倍,0.92倍,1.80倍和1.45倍,乙醇收率为31.07%,较以糖蜜原料为唯一碳源时提高36.26%。【结论】突变株Saccharomyces cerevisiae AQ较原始菌株Saccharomyces cerevisiae A更适用于糖蜜发酵生产乙醇体系,且新型的原位预处理方法能通过增强Saccharomyces cerevisiae AQ在糖蜜培养基中的呼吸作用,提高菌株活力,从而进一步提高乙醇收率。

Promoting Ethanol Production of Cane Molasses by a Mutant Thermophilic Strain Saccharomyces cerevisiae AQ Using an in situ Pretreatment Method

Objective] The positive effects of the in situ pretreated molasses on Saccharomyces cerevisiae cell growth and ethanol production were explored and analyzed in order to develop agreen and low cost pathway of ethanol production from molasses.Methods] First, the differences of growth and ethanol production performance were compared between the original strain Saccharomyces cerevisiae A and the mutant strains Saccharomyces cerevisiae AQ;then both un-trea-ted and in situ pretreated molasses were used as fermentation substrate, in which different parameters of the mutant strain Saccharomyces cerevisiae AQ were measured, including the cell growth, budding rate, ethanol production, and the activity of intracellular superoxide dismutase (SOD), peroxidase, ATP enzyme in the cytoplasm and the mitochondria, to investigate the effects of the in situ pretreatment molasses on the physiological characteristics of Saccharomyces cerevisiae AQ.Results] During the fermentation process of molasses under high temperature condition, the mutant strain Saccharomyces cerevisiae AQ presented better stability in cell growth and ethanol yield than its original strain Saccharomyces cerevisiae A.When the in situ pretreated molasses was used as the single carbon source of Saccharomyces cerevisiae AQ, the activities of intracellular SOD enzyme, peroxidase, ATP enzyme in the cytoplasm and ATP enzyme in the mitochondria increased by 2.51, 0.92, 1.80, and 1.45 times, respectively, than that obtained in raw molasses material medium. The obtained ethanol yield from pretreated molasses was 31.07%, which was 36.26%higher than the ethanol yield obtained from molasses raw material.Conclusion] The mutant strain Saccharomyces cerevisiae AQ was more suitable for molasses ethanol fermentation system than its original strain Saccharomyces cerevisiae A, and the newin situ pretreatment method could further increase ethanol yield through enhancing Saccharomyces cerevisiae AQ respiration and cell vitality in molasses mediums.