iScience (Oct 2023)

Lytic polysaccharide monooxygenase synergized with lignin-degrading enzymes for efficient lignin degradation

  • Su Sun,
  • Fei Li,
  • Muzi Li,
  • Wenqian Zhang,
  • Zhenxiong Jiang,
  • Honglu Zhao,
  • Yunqiao Pu,
  • Arthur J. Ragauskas,
  • Susie Y. Dai,
  • Xiaoyu Zhang,
  • Hongbo Yu,
  • Joshua S. Yuan,
  • Shangxian Xie

Journal volume & issue
Vol. 26, no. 10
p. 107870

Abstract

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Summary: Even though the discovery of lytic polysaccharide monooxygenases (LPMOs) has fundamentally shifted our understanding of biomass degradation, most of the current studies focused on their roles in carbohydrate oxidation. However, no study demonstrated if LPMO could directly participate to the process of lignin degradation in lignin-degrading microbes. This study showed that LPMO could synergize with lignin-degrading enzymes for efficient lignin degradation in white-rot fungi. The transcriptomics analysis of fungi Irpex lacteus and Dichomitus squalens during their lignocellulosic biomass degradation processes surprisingly highlighted that LPMOs co-regulated with lignin-degrading enzymes, indicating their more versatile roles in the redox network. Biochemical analysis further confirmed that the purified LPMO from I. lacteus CD2 could use diverse electron donors to produce H2O2, drive Fenton reaction, and synergize with manganese peroxidase for lignin oxidation. The results thus indicated that LPMO might uniquely leverage the redox network toward dynamic and efficient degradation of different cell wall components.

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