Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401.
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354.
Proc Natl Acad Sci U S A. 2021 Mar 2;118(9). doi: 10.1073/pnas.2017381118.
Lignin is a biopolymer found in plant cell walls that accounts for 30% of the organic carbon in the biosphere. White-rot fungi (WRF) are considered the most efficient organisms at degrading lignin in nature. While lignin depolymerization by WRF has been extensively studied, the possibility that WRF are able to utilize lignin as a carbon source is still a matter of controversy. Here, we employ C-isotope labeling, systems biology approaches, and in vitro enzyme assays to demonstrate that two WRF, and , funnel carbon from lignin-derived aromatic compounds into central carbon metabolism via intracellular catabolic pathways. These results provide insights into global carbon cycling in soil ecosystems and furthermore establish a foundation for employing WRF in simultaneous lignin depolymerization and bioconversion to bioproducts-a key step toward enabling a sustainable bioeconomy.
木质素是一种存在于植物细胞壁中的生物聚合物，占生物圈有机碳的 30%。白腐真菌（WRF）被认为是自然界中降解木质素最有效的生物。虽然 WRF 对木质素的解聚作用已经得到了广泛的研究，但 WRF 是否能够将木质素用作碳源仍然存在争议。在这里，我们采用 C 同位素标记、系统生物学方法和体外酶测定来证明两种 WRF， 和 ，通过细胞内代谢途径将木质素衍生的芳香化合物中的碳转化为中心碳代谢。这些结果深入了解了土壤生态系统中的全球碳循环，并且为在同时进行木质素解聚和生物转化为生物制品的过程中利用 WRF 奠定了基础，这是实现可持续生物经济的关键步骤。
