Tu Maobing, Zhang Xiao, Paice Mike, McFarlane Paul, Saddler Jack N
FPInnovations, Paprican Division (Paprican), Pointe Claire, Quebec, Canada.
Biotechnol Prog. 2009 Jul-Aug;25(4):1122-9. doi: 10.1002/btpr.198.
The effects of surfactants addition on enzymatic hydrolysis and subsequent fermentation of steam exploded lodgepole pine (SELP) and ethanol pretreated lodgepole pine (EPLP) were investigated in this study. Supplementing Tween 80 during cellulase hydrolysis of SELP resulted in a 32% increase in the cellulose-to-glucose yield. However, little improvement was obtained from hydrolyzing EPLP in the presence of the same amount of surfactant. The positive effect of surfactants on SELP hydrolysis led to an increase in final ethanol yield after the fermentation. It was found that the addition of surfactant led to a substantial increase in the amount of free enzymes in the 48 h hydrolysates derived from both substrates. The effect of surfactant addition on final ethanol yield of simultaneous saccharification and fermentation (SSF) was also investigated by using SELP in the presence of additional furfural and hydroxymethylfurfural (HMF). The results showed that the surfactants slightly increased the conversion rates of furfural and HMF during SSF process by Saccharomyces cerevisiae. The presence of furfural and HMF at the experimental concentrations did not affect the final ethanol concentration either. The strategy of applying surfactants in cellulase recycling to reduce enzyme cost is presented.
本研究考察了添加表面活性剂对蒸汽爆破辐射松（SELP）和乙醇预处理辐射松（EPLP）酶解及后续发酵的影响。在SELP纤维素酶水解过程中添加吐温80，纤维素到葡萄糖的产率提高了32%。然而，在相同量表面活性剂存在下对EPLP进行水解，产率提高很少。表面活性剂对SELP水解的积极作用导致发酵后最终乙醇产率增加。研究发现，添加表面活性剂使两种底物48小时水解产物中游离酶的量大幅增加。还通过在存在额外糠醛和羟甲基糠醛（HMF）的情况下使用SELP，考察了添加表面活性剂对同步糖化发酵（SSF）最终乙醇产率的影响。结果表明，表面活性剂在SSF过程中略微提高了酿酒酵母对糠醛和HMF的转化率。实验浓度的糠醛和HMF的存在也未影响最终乙醇浓度。提出了在纤维素酶循环利用中应用表面活性剂以降低酶成本的策略。
