提高麦草可酶解性的常压甘油自催化预处理

针对小分子有机溶剂预处理时存在的缺陷,尝试高沸点甘油预处理木质纤维素以提高其可酶解性的研究。通过对预处理时一些关键参数进行初步优化,获得适宜预处理条件为:质量分数70%甘油溶液、液固比(麦草与甘油水溶液的质量比)20、蒸煮温度230℃和保温1 h;麦草纤维素保留率约92%,木质素脱除率达74%;常压甘油自催化预处理麦草在纤维素酶5FPU/g干底物时4,8 h纤维素酶解转化率为41.3%。结合电镜观察和红外光谱分析,初步认为常压甘油自催化预处理通过脱除木质纤维素原料中不利于纤维素酶解的组分及打破其致密不均一结构,从而提高了木质纤维素的可酶解性。

Atmospheric glycerol autocatalytic pretreatment to improve the digestibility of lignocellulosic biomass

To avoid some drawbacks existing in small molecular organsolvent pretreatment,an atmospheric glycerol autocatalytic pretreatment(AGAP) is used to enhance the enzymatic hydrolysis of lignocelluloses.With a preliminary optimization of some key operation parameters,the optimal pretreatment is shown as follows:70% of glycerol liquor,20 of liquid-solid ratio,230℃ of cooking temperature and 1 h of holding time.For the pretreated fiber,the retention rate of wheat straw cellulose is about 90% and removal efficiency of lignin is 74%.At the cellulase loading of 5 FPU/g dry substrate,its cellulose-to-glucose conversion can achieve 41.3% after 48 h.With a scanning electronic microscope and infrared spectroscopic analysis,it is suggested that the AGAP can improve the digestibility of lignocellulose by removing some enzyme-inhibitive components and disrupting the recalcitrant heterogenic structure.