State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
J Agric Food Chem. 2023 May 31;71(21):8104-8111. doi: 10.1021/acs.jafc.3c01777. Epub 2023 May 19.
In contrast to O, HO as the cosubstrate for lytic polysaccharide monooxygenases (LPMOs) exhibits great advantages in industrial settings for cellulose degradation. However, HO-driven LPMO reactions from natural microorganisms have not been fully explored and understood. Herein, secretome analysis unraveled the HO-driven LPMO reaction in the efficient lignocellulose-degrading fungus , including LPMOs with different oxidative regioselectivities and various HO-generating oxidases. Biochemical characterization of HO-driven LPMO catalysis showed orders of magnitude improvement in catalytic efficiency compared to that of O-driven LPMO catalysis for cellulose degradation. Significantly, HO tolerance of LPMO catalysis in was an order of magnitude higher than that in other filamentous fungi. In addition, natural reductants, gallic acid, in particular, presented in lignocellulosic biomass could sufficiently maintain LPMO catalytic reactions. Moreover, the HO-driven LPMO catalysis exhibited synergy with canonical endoglucanases for efficient cellulose degradation. Taken together, these findings demonstrate the great application potential of the HO-driven LPMO catalysis for upgrading cellulase cocktails to further improve cellulose degradation efficiency.
与 O 相反，HO 作为溶菌多糖单加氧酶（LPMOs）的共底物，在纤维素降解的工业环境中具有很大的优势。然而，天然微生物中 HO 驱动的 LPMO 反应尚未得到充分的探索和理解。在此，通过分泌组分析揭示了高效木质纤维素降解真菌中的 HO 驱动的 LPMO 反应，包括具有不同氧化区域选择性和各种 HO 生成氧化酶的 LPMOs。HO 驱动的 LPMO 催化的生化特性研究表明，与 O 驱动的 LPMO 催化相比，其对纤维素的降解具有数量级的催化效率提高。值得注意的是，与其他丝状真菌相比，的 LPMO 催化对 HO 的耐受性要高出一个数量级。此外，天然还原剂、特别是木质纤维素生物质中存在的没食子酸，可以充分维持 LPMO 催化反应。此外，HO 驱动的 LPMO 催化与经典内切葡聚糖酶表现出协同作用，可有效降解纤维素。总之，这些发现表明 HO 驱动的 LPMO 催化在升级纤维素酶混合物以进一步提高纤维素降解效率方面具有巨大的应用潜力。
