Crowe Jacob D, Zarger Rachael A, Hodge David B
Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology , Luleå 97187, Sweden.
J Agric Food Chem. 2017 Oct 4;65(39):8652-8662. doi: 10.1021/acs.jafc.7b03240. Epub 2017 Sep 20.
Simultaneous chemical modification and physical reorganization of plant cell walls via alkaline hydrogen peroxide or liquid hot water pretreatment can alter cell wall structural properties impacting nanoscale porosity. Nanoscale porosity was characterized using solute exclusion to assess accessible pore volumes, water retention value as a proxy for accessible water-cell walls surface area, and solute-induced cell wall swelling to measure cell wall rigidity. Key findings concluded that delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity and that the subsequent cell wall swelling resulted increased nanoscale porosity and improved enzyme binding and hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 Å dextran probe within the cell wall was found to be correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields.
通过碱性过氧化氢或液态热水预处理对植物细胞壁进行同时化学修饰和物理重组，可以改变细胞壁的结构特性，影响纳米级孔隙率。使用溶质排除法来表征纳米级孔隙率，以评估可及孔体积，用保水值作为可及水-细胞壁表面积的替代指标，并通过溶质诱导的细胞壁膨胀来测量细胞壁刚性。主要研究结果表明，碱性过氧化氢预处理脱木素降低了细胞壁刚性，与液态热水预处理生物质中观察到的有限膨胀和增加的可及表面积相比，随后的细胞壁膨胀导致纳米级孔隙率增加，并改善了酶结合和水解。发现细胞壁内90 Å葡聚糖探针可及的体积与酶结合和葡萄糖水解产率均相关，表明细胞壁孔隙率是有效水解产率的关键因素。
