School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA.
Appl Biochem Biotechnol. 2010 May;161(1-8):274-87. doi: 10.1007/s12010-009-8869-4. Epub 2009 Nov 28.
The potential economic benefits of surfactants addition on enzymatic hydrolysis of steam-exploded lodgepole pine (SELP) and ethanol-pretreated lodgepole pine (EPLP) were investigated in this study. Free cellulase readsorption on fresh substrate was used to recover and recycle cellulase enzymes during the hydrolysis of SELP and EPLP substrate. Supplementing Tween 80 during the hydrolysis could facilitate enzyme recycling for EPLP substrate. A logarithmic correlation was established between surfactant concentration and free cellulase content after lignocellulosic hydrolysis, which was used to compute enzyme cost savings over various Tween 80 concentrations. A simple economic analysis of enzyme cost savings versus the cost of surfactant was undertaken. The results indicated that the addition of Tween 80 (priced at US $0.25/kg) during the hydrolysis of the EPLP substrate could save 60% of the total enzyme cost at concentrations in the 0.025% to 0.2% range. The addition of Tween for the hydrolysis of the SELP substrate significantly reduced the material cost by 24% per 1 gal of ethanol produced, and the ethanol production cost could be reduced by 8.6% with the addition of Tween and enzymes recycle for the hydrolysis of SELP substrate. A schematic concept of recycling enzyme and surfactant was also presented with a recirculation of process streams during hydrolysis. Further analysis indicated a 66% reduction in total enzyme cost could potentially be achieved under the concept.
本研究考察了添加表面活性剂对蒸汽爆破云杉（SELP）和乙醇预处理云杉（EPLP）酶解的潜在经济效益。在 SELE 和 EPLP 水解过程中，利用游离纤维素酶对新鲜底物的再吸附作用来回收和循环利用纤维素酶。在水解过程中添加吐温 80 有助于 EPLP 底物的酶回收。在木质纤维素水解后，建立了表面活性剂浓度与游离纤维素酶含量之间的对数相关性，用于计算不同吐温 80 浓度下的酶节省成本。对酶节省成本与表面活性剂成本的简单经济分析进行了研究。结果表明，在 EPLP 底物水解过程中添加吐温 80（价格为 0.25 美元/千克），在 0.025%至 0.2%的浓度范围内可节省总酶成本的 60%。在 SELP 底物的水解中添加吐温可将每加仑乙醇的材料成本降低 24%，并且通过添加吐温和酶循环利用 SELP 底物的水解，可将乙醇生产成本降低 8.6%。还提出了一种回收酶和表面活性剂的示意图概念，并在水解过程中实现了工艺流的再循环。进一步的分析表明，在该概念下，总酶成本可能降低 66%。
