细胞稀释强化硅橡胶膜生物反应器连续乙醇发酵

Enhancement of Continuous Ethanol Fermentation in a Silicone Rubber Membrane Bioreactor with Cell Dilution

通过原位重力沉降分离酵母和渗透汽化分离乙醇构建了细胞稀释连续乙醇发酵的硅橡胶膜生物反应器。采用酿酒酵母,以0.05/h的细胞稀释率在膜生物反应器中实现了170 h的连续稳定乙醇发酵。重力沉降分离酵母对硅橡胶膜生物反应器产生的细胞稀释作用可以通过反应器内酵母自身生长得到平衡,发酵液细胞浓度稳定在5g/L。渗透汽化原位分离使发酵液内乙醇浓度维持在50 g/L。细胞稀释膜生物反应器连续发酵的乙醇体积产率达到1.63 g/(L.h),相对于同等工艺参数的细胞封闭循环膜生物反应器连续乙醇发酵细胞比产率提高了31%。

A silicone rubber membrane bioreactor with cell dilution for ethanol fermentation has been built based on in-situ gravitational settling and pervaporation.Stable ethanol fermentation was maintained for 170h using Saccharomyces cerevisiae at a cell dilution rate of 0.05 h-1.Dilution effect of cell by gravitational settling of yeasts was counterbalanced by natural cell growth,resulting in a stable cell concentration of 5 g/L in the bioreactor.Ethanol productivity in the membrane bioreactor reached 1.63 g/（L·h） during continuous fermentation.The cell-specific productivity of continuous fermentation in the membrane bioreactor with cell dilution was increased by 31% in comparison with that in a counterpart with close cell circulation.