LC-MS/MS based profiling revealed thermophilic fungus Crassicarpon thermophilum strain 6GKB as a prolific producer of cellobiose dehydrogenase (CDH; AA8). CDH is an important component of the newly discovered oxidative system comprising CDH and lytic polysaccharide monooxygenases (LPMO), known for its ability to enhance degradation of lignocellulosics. CDH from C. thermophilum was purified using culture extract harvested after 7 days of culture on cellulose, wheat bran and rice straw (CWR) based medium by employing hydrophobic interaction chromatography in tandem with ion exchange chromatography. SDS-PAGE confirmed enzyme purity and presence of a single protein band at a molecular weight of 84 kDa. The purified CDH (ctCDH) was found to be stable under optimal temperature (50 °C) and pH (5.0) conditions with t_1/2 of 360 min. The Kinetic characterization of ctCDH showed similar affinity (4.5 and 4.0 mM) and specificity (2.6 × 10⁵ and 2.5 × 10⁵ mM⁻¹ s⁻¹) of the enzyme towards cellobiose and lactose, respectively. In addition, coalescence of spectral and electron acceptor studies confirmed ctCDH to be a flavocytochrome. Through this study, we further demonstrate the potential of ctCDH alone and in combination with LPMO to enhance the efficiency of commercial cellulase Cellic CTec2 to hydrolyze alkali and acid treated bagasse by upto 1.35 folds. Conclusively, ctCDH reported in this study is a potent enzyme that could be utilized for numerous biotechnological applications involving enzymatic degradation of lignocellulosic biomass.

基于LC-MS / MS的分析显示嗜热真菌Crassicarpon thermophilum菌株6GKB是纤维二糖脱氢酶（CDH; AA8）的多产生产者。CDH是新发现的包含CDH和溶解性多糖单加氧酶（LPMO）的氧化系统的重要组成部分，众所周知，CDH具有增强木质纤维素降解的能力。嗜热梭菌的CDH使用疏水相互作用色谱法和离子交换色谱法，在纤维素，麦麸和稻草（CWR）基培养基上培养7天后收获的培养物提取物，可以纯化得到的粗产物。SDS-PAGE证实了酶的纯度以及分子量为84 kDa的单个蛋白条带的存在。发现纯化的CDH（ctCDH）在最佳温度（50°C）和pH（5.0）条件下稳定，t _1/2为360分钟。ctCDH的动力学表征显示相似的亲和力（4.5和4.0 mM）和特异性（2.6×10 ⁵和2.5×10 ⁵  mM ^-1  s ^-1）分别针对纤维二糖和乳糖的酶）。此外，光谱和电子受体研究的合并证实了ctCDH是黄素细胞色素。通过这项研究，我们进一步证明了ctCDH单独使用以及与LPMO联合使用可以增强商业纤维素酶Cellular CTec2水解碱和酸处理的蔗渣的效率达1.35倍。结论是，这项研究中报道的ctCDH是一种有效的酶，可用于涉及木质纤维素生物质酶促降解的众多生物技术应用中。