Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, United States.
College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China.
Int J Biol Macromol. 2020 Jun 15;153:433-440. doi: 10.1016/j.ijbiomac.2020.02.262. Epub 2020 Feb 25.
Non-enzymatic degradation of wood via a chelator-mediated Fenton (CMF) system is the primary method for initial attack in brown rot fungal decomposition of wood, the most common type of fungal degradation of terrestrial carbon biomass on the planet. In this study, the degradation of thin films of cellulose and chitin by a CMF system was investigated and compared to enzymatic hydrolysis. The kinetics of the rapid cellulose and chitin deconstruction and the morphologies of the degraded cellulose and chitin surfaces were studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM), respectively. The QCM-D results quantitatively indicated that ~90 wt% of the regenerated cellulose or chitin was capable of being deconstructed by CMF action alone. While enzymatic degradation was consistent with stripping of layers from the surface of the cellulose or chitin films, the CMF process exhibited a pronounced two stage process with a rapid initial depolymerization throughout the films. The initial degradation rates for both model surfaces by the CMF system were faster than enzyme action. This research suggests that the CMF process should be applicable for the deconstruction of a wide variety of polysaccharides over Fenton chemistry alone.
通过螯合剂介导的芬顿（CMF）系统对木质素进行非酶降解是褐腐真菌分解木质素的初始攻击的主要方法，褐腐真菌是地球上陆地碳生物量最常见的真菌降解类型。在这项研究中，研究了 CMF 系统对纤维素和几丁质薄膜的降解，并将其与酶水解进行了比较。通过石英晶体微天平耗散监测（QCM-D）和原子力显微镜（AFM）分别研究了快速纤维素和几丁质解构的动力学和降解纤维素和几丁质表面的形态。QCM-D 结果定量表明，仅通过 CMF 作用就能够解构约 90wt%的再生纤维素或几丁质。虽然酶降解与纤维素或几丁质薄膜表面的层剥落一致，但 CMF 过程表现出明显的两阶段过程，在整个薄膜中具有快速的初始解聚。CMF 系统对两种模型表面的初始降解速率均快于酶作用。这项研究表明，CMF 过程应该适用于单独通过芬顿化学对各种多糖进行解构。
