Kim Sung Bae, Kim Hyun Joo, Kim Chang Joon
Department of Chemical and Biological Engineering and ERI, Gyeongsang National University, Jinju 660-701, Korea.
Appl Biochem Biotechnol. 2006 Spring;129-132:486-95. doi: 10.1385/abab:130:1:486.
Methods of increasing the enzymatic digestibility of waste newspaper by adding Tween (TW)-20 and 80 surfactants were investigated. Tween-series surfactants were selected because these surfactants increase cellulase activity during enzymatic hydrolysis and do not inhibit cell growth in downstream fermentation processes. When surfactant was used in a pretreatment, a benefic effect was expected in the enzymatic hydrolysis stage owing to surfactant carry-over from the pretreatment stage immediately upstream of the hydrolysis. However, because it was necessary to wash the pretreated substrate with water to remove inhibitors produced during pretreatment, no added benefit was obtained. When surfactant was used in the pretreatment only, it was found that it had a marked effect on digestibility and that this effect was higher at lower enzyme loadings. Also, TW-80 was found to be more effective than TW-20, and the addition of enzyme and TW-80 to substrate at the beginning of enzyme reaction was found to most effectively increase digestibility. When TW-80 was added into either the pretreatment stage or the hydrolysis stage the digestibilities of untreated sample increased by approx 40%, whereas an increase of only 45% was observed when TW-80 was added to both stages. These results show that the addition of surfactant to either the pretreatment or the enzymatic hydrolysis stage is sufficient to increase digestibility.
研究了通过添加吐温（TW）-20和80表面活性剂提高废报纸酶消化率的方法。选择吐温系列表面活性剂是因为这些表面活性剂在酶水解过程中可提高纤维素酶活性，且在下游发酵过程中不抑制细胞生长。当表面活性剂用于预处理时，由于其从紧接水解上游的预处理阶段残留，预计在酶水解阶段会产生有益效果。然而，由于需要用水洗涤预处理后的底物以去除预处理过程中产生的抑制剂，因此未获得额外益处。当仅在预处理中使用表面活性剂时，发现其对消化率有显著影响，且在较低酶负载量下这种影响更高。此外，发现TW-80比TW-20更有效，并且在酶反应开始时将酶和TW-80添加到底物中最有效地提高了消化率。当将TW-80添加到预处理阶段或水解阶段时，未处理样品的消化率提高了约40%，而当将TW-80添加到两个阶段时，仅观察到45%的提高。这些结果表明，在预处理或酶水解阶段添加表面活性剂足以提高消化率。
