CAJ | 학술논문

为充分利用白酒丢糟资源,探讨了酸酶联合水解法对其进行糖化以获得可发酵糖的可行性.以木糖和还原糖浓度为指标,研究温度、固液比、混合酸浓度和时间等因素对酸解效果的影响;在此基础上分析纤维素酶对酸解残渣(AHR)的酶解历程,并利用扫描电镜(SEM)、红外光谱(FTIR)和X-衍射(XRD)技术考察不同水解阶段丢糟的结构特性变化.结果表明,丢糟在温度为100℃、固液比为1:12 g/mL和酸浓度为2.0%的条件下经混合酸水解120 min可获得59.32 g/L还原糖和6.49 g/L木糖,该酸解阶段的半纤维素和纤维素转化率分别为77.38%和62.50%,木质素溶出率为43.50%.AHR在纤维素酶用量为4000 U/g原料、温度为45℃和pH值为4.8的条件下继续作用2.5 h可获得13.27 g/L还原糖,该酶解阶段的纤维素转化率为66.67%,酶解率高达90.73%.结构特性研究表明,水解作用前后的丢糟形貌结构变化明显,孔隙率和比表面积增加,有利于纤维素酶对AHR中纤维结晶区的作用.FTIR和XRD结果显示,水解前后的特征组分所对应的吸收峰强度发生了变化,相对结晶度逐渐提高.白酒丢糟经酸酶联合水解作用转化为可发酵糖具有可行性.该研究可为丢糟生物质发酵制备乙醇提供理论基础.
위충분이용백주주조자원,탐토료산매연합수해법대기진행당화이획득가발효당적가행성.이목당화환원당농도위지표,연구온도、고액비、혼합산농도화시간등인소대산해효과적영향;재차기출상분석섬유소매대산해잔사(AHR)적매해역정,병이용소묘전경(SEM)、홍외광보(FTIR)화X-연사(XRD)기술고찰불동수해계단주조적결구특성변화.결과표명,주조재온도위100℃、고액비위1:12 g/mL화산농도위2.0%적조건하경혼합산수해120 min가획득59.32 g/L환원당화6.49 g/L목당,해산해계단적반섬유소화섬유소전화솔분별위77.38%화62.50%,목질소용출솔위43.50%.AHR재섬유소매용량위4000 U/g원료、온도위45℃화pH치위4.8적조건하계속작용2.5 h가획득13.27 g/L환원당,해매해계단적섬유소전화솔위66.67%,매해솔고체90.73%.결구특성연구표명,수해작용전후적주조형모결구변화명현,공극솔화비표면적증가,유리우섬유소매대AHR중섬유결정구적작용.FTIR화XRD결과현시,수해전후적특정조분소대응적흡수봉강도발생료변화,상대결정도축점제고.백주주조경산매연합수해작용전화위가발효당구유가행성.해연구가위주조생물질발효제비을순제공이론기출.
China is a big country of white spirit production and consumption. When brewing white spirit, large amounts of distiller’s grains (DG) are left over, which are as the byproduct in white spirit production. In virtue of high content of cellulose and hemicellulose, DG is a kind of lignocellulosic biomass. In order to make full use of a distiller′s grains (DG), the feasibility of using DG in making fermentable sugars by the two-step hydrolysis method of mixed acid and cellulase was explored. The key parameters of temperature, mixed acid concentrations, solid-liquid ratio and hydrolysis time were studied with the index of the concentrations of reducing sugar and xylose. In addition, the structural characteristics of DG in different hydrolysis stages were examined by means of scanning electronic microscopy (SEM), infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results indicated that there was 59.32 g/L reducing sugar and 6.49 g/L xylose in the conditions of temperature 100℃, solid-liquid ratio 1:12 g×mL-1, acid concentrations 2.0%and time 120 min, with the conversions of 77.38%and 62.50% for hemicellulose and cellulose, respectively. There were 13.27 g/L reducing sugars in the enzymatic hydrolysis conditions of cellulase dosage 4000 U/g, temperature 45℃, pH value 4.8 and time 2.5 h. The conversion rate and enzymatic hydrolyzation of the cellulose were 66.67%and 90.73%, respectively. The studies of structural characteristics showed that the changes in morphology caused by acid and enzymatic hydrolysis successively were significant in comparison to those of feedstock, resulting in increasing surface exposure and porosity. The disorganized morphological structure of AHR allows for greater accessibility to cellulase, which facilitates enzymatic hydrolysis. The spectrograms of FTIR and XRD suggested that the characteristic strength peaks for the corresponding typical functional groups of each component were changed and the crystallinity index of the solid residues were increased, compared with DG. In short, the saccharification process based on the combined hydrolysis of acid and enzyme to produce fermentable sugars was feasible and efficient.