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采用室内实验方法,研究了酸-超声联合预处理稻草对其化学组成以及糖化效果的影响,并与传统酸预处理法的效果进行了对比。结果表明,与未经处理的稻草相比,经酸-超声波处理的稻草其半纤维素、木质素含量最高分别减少了64.46%、62.19%,纤维素含量最高则上升了73.20%,而酸处理的稻草相应数值只能达到56.72%、59.90%及53.41%。同时分别对两种方法的稻草糖化的工艺条件通过正交试验进行了优化,得出两种方法的稻草最佳糖化条件均为:pH值为4.8,温度为45℃,酶浓度为20mg.g-1。在该条件下,对于酸-超声波预处理稻草,在糖化108h以后还原糖浓度稳定并达到最大值26.4g.L-1,而对于酸预处理稻草,在糖化120h以后还原糖浓度才稳定并达到最大值26.2g.L-1,且前者能比后者产生更多的葡萄糖以及更少的木糖,更有利于提高后续酒精发酵的效率。
The effects of acid-ultrasound on the chemical composition and saccharification of rice straw were studied by laboratory experiments. The results were compared with the results of conventional acid pretreatment. The results showed that compared with untreated straw, the content of hemicellulose and lignin of straw treated with acid-ultrasonic was reduced by 64.46% and 62.19%, respectively, and the content of cellulose increased by 73.20% The corresponding value of straw only reached 56.72%, 59.90% and 53.41%. In the meantime, the optimal conditions for straw saccharification of the two methods were optimized by orthogonal test. The optimum saccharification conditions of the two methods were as follows: the pH was 4.8, the temperature was 45 ℃, the enzyme concentration was 20mg.g. -1. Under this condition, the concentration of reducing sugar was stable and reached the maximum value of 26.4gL-1 after acid-ultrasonic pretreatment for straw for 120h, while the concentration of reducing sugar was stable and reached the maximum after 120h 26.2gL-1, and the former can produce more glucose and less xylose than the latter, more conducive to improve the efficiency of subsequent alcohol fermentation.