利用酿酒酵母Saccharomyces cerevisiae BY4742对小麦秸秆同步糖化发酵(simultaneously saccharification and fermentation,SSF)生产燃料乙醇的条件进行了研究,系统考察和研究了温度、固体含量、纤维素酶投加量、酵母菌浓度对SSF过程中乙醇浓度和产率的影响,并对以上参数做了初步优化,以提高最终乙醇浓度和产率。结果表明,小麦秸秆同步糖化发酵乙醇的最优条件为:温度38℃,固体含量16.0%(m/V),纤维素酶投加量35FPU/g底物,酵母菌浓度8 g/L。在此条件下,NaOH预处理后的小麦经过120 h同步糖化发酵,乙醇浓度达到最大值,为38.32 g/L,产率达理论产率的71.71%,木糖浓度为12.94 g/L。

Experiments were carried out on the conditions of bioethanol production from wheat straw through simultaneously saccharification and fermentation using Saccharomyces cerevisiae BY4742.The effects of temperature,solid content,enzymeloading and yeast concentration on concentration and yield of ethanol in the SSF processes were systematically investigated.These parameters were further optimized to increase the final concentration and yield of ethanol.The results showed that the optimum conditions for SSF of wheat straw were as follows: temperature 38℃,solid content 16.0%(w/v),enzyme loading 35 FPU/g and substrate and yeast concentration 8 g/L.The maximum ethanol concentration reached 38.32 g/L,which was equivalent to 71.71% of the theoretical ethanol yield,with xylose concentration of 12.94 g/L obtained after 120 h SSF of NaOH pretreated wheat straw under the optimized conditions.