水稻脆性秸秆发酵产纤维乙醇的研究

Study on cellulosic ethanol fermentation of brittle rice straw

以水稻脆性秸秆为原料进行了发酵产乙醇的研究。用水稻脆性秸秆比用作对照的普通秸秆的半纤维素和木质素含量分别高17%和5%,纤维素含量低15%。采用浓度为2%(w/v)的硫酸进行秸秆预处理后,脆性秸秆稀酸水解液中葡萄糖含量为普通秸秆的1.38倍;每克脆性秸秆产生的木糖和阿拉伯糖比普通秸秆分别高出12.0 mg和3.9 mg;两种秸秆酸水解液中副产物乙酸、糠醛和5-羟甲基糠醛的浓度差异不显著。经过纤维素酶进一步处理后,每克脆性秸秆得到的总还原糖量为(541.2±8.0)mg,比普通秸秆高出41.9 mg。Escherichia coli SZ470利用酸预处理且酶促糖化的两种秸秆发酵72 h后,脆性秸秆发酵的乙醇产量可达(10.9±0.4)g/L,为普通秸秆的1.1倍。

Cellulosic ethanol fermentation was studied by using brittle rice straw as the raw mate- rial. The hemicellulose and lignin content of rice brittle straw was more than 17% and 5% higher than that of ordinary straw, respectively. The cellulose content of brittle rice straw was less than 15%. After pretreatment in 2% （w/v） sulfuric acid solution, content of glucose that obtained from brittle straw was more than 1.38 times higher than ordinary straw. Xylose and arabinose produced by brittle straw was more than 12.0 mg and 3.9 mg （per gram dry straw） higher than that respec- tively. Concentration of acetic acid, furfural and 5-HMF in the hydrolysate had no obvious differ- ence. The total production of reducing sugar obtained from per gram brittle straw could reach 541.2＋8.0 mg after further processing of cellulase , that was more than 41.9 mg higher than that of the ordinary straw. Brittle straw through acid pretreatment and enzyme saccharification treatment were fermented by recombinant Escherichia coli strain SZ470 for 72 h, the yield of ethanol （per litre） was I0.9e0.4 g, which was 1.1 times of the ordinary straw.