Role of Lignin in Biochemical Conversion of Lignocellulose Biomass into Fuels and Biochemicals

在将木质纤维素材料如木材和农业残留物生化转化为燃料和化学品的典型过程中，必须去除半纤维素或木质素，使得纤维素酶可以更容易地接近纤维素分子。木质素占植物质量的20%-30%，因物种而异。木质素充当限制纤维素酶接近纤维素的物理屏障;并且木质素和木质素衍生物也与纤维素酶结合，所谓的非生产性结合。本研究的目的是从根本上了解木质纤维素基质中的木质素如何影响生物质转化。我们将使用EM，XPS，CLSM，AFM来确定预处理过程后木质素的重新分布，并将使用我们实验室专门设计的AFM系统来研究纤维素酶与木质素之间的相互作用。木质素含量，木质素分布，以及不同类型的木质素在底物和水解系统中的组成将被研究其对底物的酶水解的贡献。世界各地在研究方面作出了许多努力，以开发生物质转化技术;然而，经济上可行的技术很少。很明显，生物质转化过程中更基本的问题需要回答。该项目将在微米和纳米尺度上对木质纤维素生物质结构和化学成分有新的认识，并将这些特征与底物消化率联系起来。预计从这项研究中获得的新知识将为改进现有的和开发新的生物化学转化技术提供至关重要的信息，这些技术在经济上是可行的，可用于工业应用。该研究计划涉及化学工程，化学，生物学，工业过程以及最先进的表面和纳米级分析技术领域的专业知识，因此为加拿大培训HQP提供了独特的机会。

In a typical process of biochemical conversion of lignocellulose materials such as wood and agriculture residues into fuels and chemicals, either hemicellulose or lignin has to be removed so that cellulase can access cellulose molecules more easily. Lignin makes up 20%-30% of plant mass varying with species. Lignin acts as a physical barriers restricting access of cellulases to cellulose; and lignin and lignin derivatives also bind with cellulase, so called non-productive binding. The objective of this study is to obtain fundamental understanding of how lignin in the lignocellulose substrate affects biomass conversion. We will use EM, XPS, CLSM, AFM to determine the redistribution of lignin after a pretreatment process, and will use a specially designed AFM system in our lab to study the interactive forces between cellulases and lignin. Lignin content, lignin distribution, and the composition of different types of lignin in substrates and in hydrolysis systems will be investigated for its contribution to substrate recalcitrance to enzyme hydrolysis. Many efforts have been made in research around the world in order to develop technologies for biomass conversion; however, economically viable technologies are scarce. It is clear that more fundamental questions in biomass conversion process need to be answered. This proposed project will gaining new understanding of lignocellulose biomass structure and chemical components at micro- and nano-scale, and link these characteristics to the substrate digestibility. It is expected that new knowledge obtained from this study will provide crucially important information for improving the existing and developing new biochemical conversion technologies which is economically viable for industrial applicaitons. This research program involves expertise in the areas of chemical engineering, chemistry, biology, industrial processes, and state-of-the-art surface and nanoscale analysis techniques, and thus provides a unique opportunity for training HQP’s for Canada.