自絮凝颗粒酵母酒精连续发酵并联产酵母工艺过程的研究

【作者】 王江龙；

【导师】 白凤武；

【作者基本信息】 大连理工大学 ， 生物化工， 2004， 硕士

【摘要】 在一小型悬浮床生物反应器中运用中国数学会方开泰教授开发的均匀设计法及相应的软件系统UD3.0，对自絮凝颗粒酵母高密度培养条件进行了研究，确定了各因素与目标函数之间的关系，并通过综合调优，获得了最佳培养条件： 1)培养温度30℃，反应器通气量0.714vvm； 2)培养基组成：糖液浓度220g／L，玉米浆添加量0.4％，（NH₄）₂HPO₄添加量3.0g／L。 在稀释速率控制为0.02h^-1时，在上述条件下进行絮凝酵母的验证性连续培养实验，培养液中的酵母细胞密度达到了18g（d.w）／L以上。 在此基础上，在一套多级串联小型悬浮床生物反应器系统中，以双酶法制备的玉米粉糖化液为底物，进行了自絮凝颗粒酵母酒精连续发酵并联产酵母的实验研究。种子罐定时为各发酵罐补充活性好的酵母，同时从各发酵罐定量采出酵母。在平均发酵时间为20h条件下，发酵终点酒精浓度达到12％（v／v）以上，残还原糖和残总糖分别在5g／L和10g／L以下，每天联产酵母18.4g（干重），约占酒精产量的5％，发酵过程酵母增殖率为72.3％。 取得的这些实验结果，为正在建设的一套万吨级规模自絮凝颗粒酵母酒精发酵并联产酵母装置的运行奠定了良好的技术基础。更多还原

【Abstract】 When the specific growth rate u, residual sugar level S and biomass concentration X were designated to be the target function, respectively, the high density cultivation of a self-flocculating yeast strain, SPSC01, a fusant from Saccharomyces cerevisiae and Schizosaccharomyces pombe, was investigated in a laboratory scale airlift suspended-bed bioreactor using uniform design strategy and its corresponding software UD3.0, developed by Prof. Kaitai Fang, Chinese Mathematics Association. The cultivation parameters were optimized. The cultivation temperature should be controlled at 30℃, whereas the airflow rate 0.012vvm and the medium composed of sugar 220g/L, corn steep liquor .4g/L and (NH4)2HPO4 3.0g/L. These optimized cultivation parameters were validated experimentally and a yeast cell density as high as 18g(d.w)/L was achieved when the medium was fed at a dilution rate of 0.02 h-1.Then, an ethanol fermentation system composed of three/four laboratory scale airlift suspended-bed bioreactor in series and with a total working volume of 4800 ml was established and continuous ethanol fermentation coupled with the production of yeast was carried out experimentally. When the dilution rate based on the total working volume of the bioreactor system was controlled at 0.05 h-1, an average ethanol concentration of 12% (v/v), together with residual sugar level of 5 g/L and 10 g/L for reducing and total ones, respectively, was achieved. At the same time, 18.4g (d.w) yeast was produced daily and this amount of yeast was calculated to be 5% of ethanol produced over a period of 30 days’ running.更多还原