木薯秸秆发酵产糖预处理工艺的研究

Pretreatment Technology for Saccharification by Fermentation of Cassava Straw

摘要:

为了充分利用生物质资源，本文对农产废弃物-木薯秸秆的水解产糖工艺进行了研究。首先，以纤维素的含量为指标，研究了常规碱处理、微波/碱处理和超声波/碱处理三种方法对木薯秸秆进行预处理的效果。结果显示：经过2%（m/m）NaOH溶液结合微波处理40 min后得到的木薯秸秆，其纤维素含量最高(54.1%)，但重量损失也最大(61.3%)。这是由于微波辐射增加了半纤维素在碱液中的溶解度，而使半纤维素被除去，纤维素含量相对增加。然后，对三种预处理方法得到的木薯秸秆进行发酵产糖研究，实验显示微波/碱处理得到的底物经绿色木霉降解可得到最高的还原糖产量，而对木薯秸秆糖化所得残渣的主要化学成分进行分析也证明了这一点。因此，为有利于后期木薯秸秆的发酵产糖，微波/碱处理是木薯秸秆糖化前的一种理想的预处理方法。

Abstract:

The technology for hydrolysis and saccharification of cassava straw, a kind of agricultural waste, was investigated in this paper for making full use of biomass resources. The effects of conventional alkali treatment, microwave/alkali treatment and ultrasonic/alkali treatment on the pretreatment of cassava straw were studied first by using the cellulose content as an index. The results showed that the cassava straw, obtained by the treatment of 2%（m/m）NaOH solution and microwave for 40 min, had the highest cellulose content (54.1%) and weight loss (61.3%). This was because that the microwave radiation increased the solubility of hemicellulose in alkali solution, which removed the hemicellulose and increased the cellulose content. Then, the cassava straw, obtained by three pretreatment methods, was fermented for saccharification, and results showed that the substrates, obtained after microwave/alkali treatment, would have the highest content of reducing sugar with the treatment of degradation by Trichoderma viride. Consequently, microwave/alkali treatment was an ideal pretreatment method for the pre-saccharification of cassava straw, which was beneficial to the fermentation of cassava straw in the furture.