氢氧化钠和碱性双氧水预处理对水稻秸秆酶解效果的影响

为提高水稻秸秆生物转化产糖效率，分别用氢氧化钠和碱性双氧水对其进行预处理，并考察处理液浓度、温度和时间对木质纤维素酶解糖化效果的影响. 通过分析预处理前后水稻秸秆组分和结构变化，揭示氢氧化钠预处理和碱性双氧水预处理对水稻秸秆酶解效果的影响机理. 结果表明:①在80 ℃的条件下，使用1.25%的氢氧化钠对水稻秸秆水浴处理3 h后效果较好，且酶解72 h后还原糖含量为480.81 mg/g. ②在50 ℃的条件下，使用碱性双氧水(1.5%的氢氧化钠+2%的双氧水)对水稻秸秆水浴处理5 h后效果较好，且酶解72 h后还原糖含量为575.85 mg/g. ③与未预处理的水稻糖化效果(132.7 mg/g)相比，经氢氧化钠预处理和碱性双氧水预处理后，水稻秸秆酶解产糖率分别提高了262.3%和336.2%. ④扫描电镜显示，经氢氧化钠和碱性双氧水预处理后，水稻秸秆的比表面积均显著增加，表面结构更加疏松. ⑤红外光谱和X射线衍射光谱表征显示，氢氧化钠预处理和碱性双氧水预处理均可消解水稻秸秆中的木质素并使其转化成纤维素，从而可以促进后续的酶解糖化效果. 研究显示，氢氧化钠预处理和碱性双氧水预处理都能较好地促进水稻秸秆的酶解糖化过程，得到较高的糖含量. 

Effect of Sodium Hydroxide and Alkaline Hydrogen Peroxide Pretreatment on Enzymatic Hydrolysis of Rice Straw

In order to improve the biological saccharification efficiency, rice straw was pretreated with sodium hydroxide and alkaline hydrogen peroxide, respectively. The effects of liquid concentration, temperature and time were used to investigate the effectiveness of the two pretreatment methods were investigated. Moreover, the effect mechanism was revealed by analyzing the changes in structure and composition of rice straw before and after the pretreatment. The results showed that under the condition of 80 ℃, 1.25% sodium hydroxide had a better effect on rice straw after 3 h water bath treatment, and the reducing sugar content was 480.81 mg/g after 72 h enzymatic hydrolysis. Under the condition of 50 ℃, the effect of alkaline hydrogen peroxide (1.5% NaOH, 2% H₂O₂) on rice straw after water bath for 5 h was better, and the reducing sugar content was 575.85 mg/g after 72 h enzymatic hydrolysis. The reducing sugar yield from rice straw with sodium hydroxide and alkaline hydrogen peroxide pretreatment increased by 262.3% and 336.2%, respectively, compared with rice straw without pretreatment (132.7 mg/g). Scanning electron microscope analysis indicated that the specific surface area of rice straw pretreated with sodium hydroxide and alkaline hydrogen peroxide increased obviously, and the structure became looser and porous. Fourier transform infrared spectrum and X-ray diffraction spectrum analyses showed that after sodium hydroxide and alkaline hydrogen peroxide pretreatment, the lignin in rice straw was digested into cellulose, which improved biological saccharification efficiency.