预处理酶水解糖化是木质纤维原料生物转化的关键步骤，而随着生物技术的发展，纤维素酶的成本已经取得了突破性进展，但是预处理因为能耗、环保及效率等问题成为木质纤维高值化利用的瓶颈。申请者前期研究表明BIVIS双螺旋挤压机协同酸碱温和条件下预处理玉米秸秆，可在大幅度降低预处理过程能耗的同时，使半纤维素的溶出率达到70%，纤维素酶解得率达到92%。本项目旨在通过对物理化学预处理木质纤维原料化学组分和超微结构变化的研究，阐明这种新型预处理方法温和条件下溶出半纤维素、木质素及高效促进纤维素酶解的机理。然后，筛选或复配适合的半纤维素酶、纤维素酶，建立酸溶半纤维素和碱处理纤维素耦合酶水解糖化的新路线，以在系统内实现所需要的反应环境，解决化学品回收及环保问题。最后，根据机理性认识，进一步优化系统参数，建立一套经济高效环保温和的预处理糖化方法,为木质纤维原料转化为能源、材料或化学品的产业化奠定基础。

Pretreatment and enzymatic saccharification are the key steps of biomass conversions. With the development of biotechnology, the cost of cellulase has been reduced remarkably, while the high cost of pretreatment is still the bottleneck of high-value utilization of lignocellulose, due to some problems, such as high energy consumption, environmental protection, and low efficiency. Our previous studies showed that, after the BIVIS pretreatment of corn stover under mild conditions, 70% of the dissolution rate of hemicellulose and 92% of the enzymatic hydrolysis yield of cellulose could be obtained. In the mean time, the energy consumption was lowered significantly. In this research, the changes of chemical components and ultrastructure of biomass materials during the physical and chemical pretreatment will be studied, to elucidate the mechanism of the dissolution of hemicellulose and lignin under mild pretreatment conditions, and the effective promotion of enzymatic hydrolysis of cellulose. Subsequently, a new approach of simultaneous saccharification and co-fermentation of acid-soluble hemicellulose together with alkaline pretreated cellulose will be established, through the selection or combination of hemicellulase, and cellulase, as well as thermoanaerobic bacteria, which can simultaneously ferment pentose and hexose. The goal of the co-fermentation is to realize the needed reaction environment in the system and resolve the issues of chemical recycling and environmental protection. At last, based on the understanding of the mechanism, the system parameters will be further optimized, to set up a method of mild pretreatment and saccharification, which are economically efficient and environment-friendly. These studies will lay the foundation for the industrialization of the conversion of lignocelluloses into bioenergy, biomaterials or biochemicals.