Study On Miscanthus’ Lignocellulose Enzymolysis Degradation Effect Of Different Pretreatment

In order to alleviate energy depletion, more and more scientists involved in researching renewable energy. As the second generation of energy plants, Miscanthus have the advantages of high photosynthetic efficiency, low planting cost, low risk for food crisis, high output compared with the first generation of energy plants such as corn and potatoes. After60Co γ-ray irradiation, enzymolysis efficiency of Miscanthus can be enhanced. Irradiation dose in the0～1200KGy range, with the increase of radiation dose, the content of reducing sugar production was increased. In consideration of enzymolysis efficiency and cost saving,400KGy60Co γ-ray irradiation is advisable. This experiment selected Miscanthus with400KGy60Co γ-ray irradiation planted in teaching and researching base of Hunan Agricultural University, combined with three pretreatment methods that were dilute acid, dilute sodium hydroxide and alkaline hydrogen peroxide, investigated the effects for enzymolysis efficiency improvement. According to the yield of reducing sugar, optimized the three pretreatment methods.This article mainly included the following contents:1、After400KGy60Co γ-ray irradiation, cellulose、hemicellulose lignin of Miscanthus were from34.94%、31.34%、18.38%dropped to32.69%、24.01%、18.01%, respectively decreased by2.25%,7.33%and0.37%, the reducing sugar production was7.58mg/g. It’s indicated that the low dose irradiation’s degradation is not obvious to lignocellulose of Miscanthus.2、Before and after400KGy60Co γ-ray irradiation,using300U/g enzyme saccharified Miscanthus for96h at50℃,reducing sugar production were23.19mg/g and76.24mg/g. That was to said400KGy low dose irradiation could improve enzymolysis efficiency of Miscanthus at a certain extent.3、Disposed400KGy60Co γ-ray irradiated Miscanthus in0%、1%、2%、4%、6%、8%、10%H2SO4at25℃、50℃、60℃、70℃、80℃、90℃、100℃by0h、1h、2h、3h、4h、5h、6h.After optimization,the best pretreatment technique was400KGy60Co γ-ray irradiated Miscanthus disposed by5%H2SO4at90℃for4h, the reducing sugar production was60.33mg/g. Then collected the residue by H2SO4pretreatment to300U/g enzyme decomposition saccharify for96h at50 ℃,the reducing sugar production was278.38mg/g. The total reducing sugar production was338.71mg/g by these two steps, holocellulose saccharification rate was59.74%.So H2SO4pretreatment could improve enzyme decomposition saccharify of lignocellulose.4、Investigated the yield of reducing sugars of400KGy60Co y-ray irradiated Miscanthus in0%、1%、1.5%、2%、2.5%、5%、10%NaOH at25℃、50℃、60℃、70℃、80℃、90℃、100℃by sodium hydroxide pretreatment on Oh、1h、2h、3h、4h、5h、6h,.The results showed that disposed400KGy60Co y-ray irradiated Miscanthus by1.5%NaOH at100℃for4h, then saccharified it with300U/g enzyme for96h at50℃, the reducing sugar production was high to452.49mg/g. Holocellulose saccharification rate was79.80%。5、Disposed400KGy60Co y-ray irradiated Miscanthus by0%、0.5%、1%、1.5%、2%、2.5%NaOH and0%、1%、2%、3%、4%、5%H2O2on0h、3h、5h、7h、9h、11h at30℃. Investigated the promoting effect by Alkaline Hydrogen Peroxide pretreatment to enzyme decomposition saccharify of lignocellulose. The results showed that disposed400KGy60Co y-ray irradiated Miscanthus by1.2%NaOH and2%H2O2at30℃for6h, then enzyme decomposition saccharified it for96h at50℃,the reducing sugar production was505.08mg/g, holocellulose saccharification rate was89.08%.This was the best alkaline hydrogen peroxide pretreatment technique.6、Disposed400KGy60Co y-ray irradiated Miscanthus by optimization process of dilute sulfuric acid, NaOH, alkaline hydrogen peroxide, the reducing sugar production respectively were338.71mg/g、452.49mg/g、505.08mg/g,holocellulose saccharification rate were59.74%、79.80%、89.08%.According to the analysis of significant difference,there were significant differences between these three methods, and alkaline hydrogen peroxide treatment had the best effect. Alkaline hydrogen peroxide treatment effect is the best, NaOH treatment is the second, finally is dilute sulphuric acid treatment, but which all can improve the enzymolysis degradation effect of400KGy60Co y-ray irradiated Miscanthus.