自絮凝颗粒酵母发酵菊芋汁生产乙醇

Ethanol Fermentation from Jerusalem Artichoke Juice with Self-flocculating Yeast Saccharomyces cerevisiae flo

分别采用分批和连续发酵方式,对自絮凝颗粒酵母Saccharomyces cerevisiae flo发酵菊芋汁生产乙醇的条件进行了优化.与先酶解菊芋汁后再用自絮凝酵母发酵的分步糖化发酵相比,分批发酵过程中同时加入菊粉酶和自絮凝酵母的同步糖化发酵乙醇得率高,发酵时间短.当菊芋汁总糖浓度分别为105和179g/L时,同步糖化发酵的最高乙醇浓度达50和82.5g/L,比分步糖化发酵高6.4%和13.8%.在连续发酵过程中应用同步糖化发酵法,当稀释率为0.02h-1时,乙醇浓度约为90g/L时达到稳定状态,乙醇得率达到理论值的90%,生产强度达2.12g/(L-h).

Batch and continuous processes were studied for ethanol production by fermentation of Jerusalem artichoke juice with self-flocculating yeast Saccharomyces cerevisiae flo.In the batch fermentation,ethanol production was more efficient with the simultaneous saccharification and fermentation（SSF）,compared with the separate hydrolysis fermentation（SHF）.The highest ethanol concentrations of 50 and 82 g/L were achieved within 26 and 34 h when Jerusalem artichoke juice containing total sugar concentrations of 105 and 179 g/L was used in the batch SSF,6.4% and 13.8% higher than those achieved in the corresponding SHF.When the continuous SSF was applied,steady state was observed when the dilution rate of fermentation system was maintained at 0.02 h-1,and 90 g/L ethanol was produced in the effluent,being equivalent to 90% of its theoretical value.The ethanol productivity was further calculated to be 2.12 g/（L·h）.Moreover,the fermentation of unsterilized raw Jerusalem artichoke juice was examined and no contamination was observed,indicating that such a process could be more competitive in saving energy consumption.