Tween80对稻草水解及同步糖化与发酵产乳酸的影响

The Effect of Surfactants on the Enzymatic Hydrolysis of Rice Straw and Lactic Acid Production From Rice Straw by Simultaneous Saccharification and Fermentation

在生物转化纤维原料产乳酸的过程中,酶解纤维原料产还原糖是限速步骤。为了获得较高的产物产率,需较高的酶用量,这使大规模酶解废弃纤维原料的成本很高。对吐温80在酶解稻草纤维素产糖,以及耐高温乳酸菌同步糖化发酵稻草产乳酸过程中的作用进行了考察。初步结果表明,吐温80加入可使保持同等程度的水解率所需的酶用量降低,添加0.2 g/g底物的吐温80到酶用量10 FPU/g体系,水解120 h的糖产率为292.2 mg/g,比不加表面活性剂体系的糖产率增加了11%;添加0.7 g/L的吐温80进行同步糖化与发酵72 h,能使乳酸产量提高24.2%。

In the bioconversion of cellulosic materials to produce lactic acid, the enzymatic hydrolysis of cellulosic materials to produce reducing sugars is the rate-limiting step. Higher enzyme loading are needed to obtain a higher product yield, which makes the large-scale utilization uneconomic. Addition of non-ionic surfactants Tween 80 to the enzymatic hydrolysis of lignocellulose can increase the conversion of cellulose into fermentable sugars. It was found that the sugar yield was up to 292.2 mg/g in the rice straw hydrolysis system at 120 h with enzyme 10 FPU/g substrate and Tween 80 0. 2 g/g substrate,and the sugar yield was increased by 11% as compared with the reference without Tween addition. Tween 80 provides an opportunity to reduce enzyme dosage while still retain the same extent of hydrolysis. The effect of Tween 80 on the simultaneous saccharification and fermentation of pretreated rice straw to lactic acid was also investigated. Results showed that addition of 0.7 g/L Tween 80 improved the lactic acid production by 24. 2% at 72 h as compared to the reference without Tween addition.