Zhou Man, Wang Yaru, Wang Yuan, Tu Tao, Zhang Jie, Wang Xiaolu, Zhang Guijie, Huang Huoqing, Yao Bin, Luo Huiying, Qin Xing
State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
College of Animal Science and Technology, Ningxia University, Ningxia, 750001, China.
Biotechnol Biofuels Bioprod. 2024 Nov 18;17(1):136. doi: 10.1186/s13068-024-02583-5.
White rot fungi produce various reactive oxygen species and ligninolytic enzymes for lignocellulose deconstruction. However, their interactions during the deconstruction of lignocellulosic structural barriers for efficient enzymatic saccharification remain unclear.
Herein, the extracellular enzyme activities and secretomic analysis revealed the sequential expression of hydroxyl radical (⋅OH) and manganese peroxidases (MnPs) for lignocellulose deconstruction by the white rot fungus Irpex lacteus. Subsequently, in vitro functional studies found that ⋅OH possessed the ability to disrupt the smooth surface structure of corn stover, resulting in increased enzymatic saccharification and cellulose accessibility. Purified recombinant MnPs from I. lacteus were able to cleave the β-O-4 bond in phenolic and non-phenolic lignin model dimers without the help of any mediators. Furthermore, the sequential pretreatment of corn stover with ⋅OH and MnP exhibited significant synergistic effects, increasing enzymatic saccharification and cellulose accessibility by 2.9-fold and 1.8-fold, respectively.
These results proved for the first time the synergistic effects of ⋅OH and MnP pretreatment in improving the enzymatic saccharification and cellulose accessibility of corn stover. These findings also demonstrated the potential application of ⋅OH and MnP pretreatment for the efficient enzymatic saccharification of corn stover.
白腐真菌产生多种活性氧物质和木质素分解酶用于木质纤维素解构。然而，在解构木质纤维素结构屏障以实现高效酶解糖化过程中它们之间的相互作用仍不清楚。
在此，细胞外酶活性和蛋白质组分析揭示了白腐菌黄孢原毛平革菌通过羟基自由基（·OH）和锰过氧化物酶（MnP）的顺序表达来进行木质纤维素解构。随后，体外功能研究发现·OH具有破坏玉米秸秆光滑表面结构的能力，从而导致酶解糖化增加和纤维素可及性提高。从黄孢原毛平革菌中纯化的重组MnP能够在没有任何介体帮助的情况下切割酚类和非酚类木质素模型二聚体中的β-O-4键。此外，用·OH和MnP对玉米秸秆进行顺序预处理表现出显著的协同效应，分别使酶解糖化和纤维素可及性提高了2.9倍和1.8倍。
这些结果首次证明了·OH和MnP预处理在提高玉米秸秆酶解糖化和纤维素可及性方面的协同效应。这些发现也证明了·OH和MnP预处理在玉米秸秆高效酶解糖化中的潜在应用。
