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氧气在环境胁迫强的高浓度乙醇发酵中具有重要作用。考察了自絮凝酿酒酵母在多种通气策略下的乙醇发酵及絮凝状况。使用氧化还原电位(ORP)检测发酵液中氧浓度并划分了厌氧、微氧和好氧状态。厌氧条件下的终点乙醇浓度最低(119±1.5 g/L);微氧条件下使用ORP精密控制氧气供给取得较高的乙醇浓度(131±1.8和125±1.7 g/L);在通气量0.2 vvm的好氧条件下,生物量、甘油量和乙醇损失皆最大,与最优收率相比较乙醇收率降低了12.2%。高通气量增强了细胞的絮凝能力,增大了絮凝体粒径。绘制雷达图进行综合评价,恒定通气0.05 vvm的过程在乙醇生产和絮凝各方面表现均突出。
Oxygen plays an important role in high-concentration ethanol fermentation with strong environmental stress. The ethanol fermentation and flocculation conditions of self-flocculating Saccharomyces cerevisiae under various aeration strategies were investigated. Redox potential (ORP) was used to detect the oxygen concentration in the fermentation broth and to classify the anaerobic, micro-aerobic and aerobic states. End point ethanol concentration was the lowest (119 ± 1.5 g / L) under anaerobic conditions; ORP precision oxygen control was used to achieve higher ethanol concentrations (131 ± 1.8 and 125 ± 1.7 g / L) under aerobic conditions; Under aerobic conditions of 0.2 vvm, biomass, glycerol and ethanol loss were both the highest, and ethanol yield decreased by 12.2% compared with the optimal yield. High ventilation increased cell flocculation capacity, increased floc size. Drawing a radar chart for comprehensive evaluation, the process of constant aeration 0.05 vvm in ethanol production and flocculation performance are outstanding.