A recent study in Biochar by Feng Wang and colleagues reveals that integrating manganese-modified biochar into solid-state fermentation systems substantially accelerates the artificial humification of agricultural lignocellulose waste. Natural humic substance formation is inherently slow, while conventional chemical methods often require high energy input and generate inhibitory byproducts, making biological alternatives attractive despite their typical rate limitations. White-rot fungi are capable of breaking down complex plant polymers through specialized extracellular enzymes, but their operational efficiency is often restricted by slow substrate degradation and complex enzymatic regulation. To overcome these challenges, researchers engineered a composite amendment combining the porous structure and aromatic properties of biochar with redox-active manganese species tailored to be compatible with fungal enzyme systems.

The experimental findings demonstrate that a 5% addition of manganese-modified biochar markedly accelerates the breakdown and conversion of wheat stover when cultivated with the white-rot fungus Phanerochaete chrysosporium. Specifically, the degradation rates for lignin, cellulose, and hemicellulose increased significantly compared to fungal inoculation alone, accompanied by extensive physical disintegration of the straw matrix. Furthermore, spectroscopic and chemical analyses indicated a progressive accumulation of humic substances and a substantial rise in polymerization indicators, demonstrating that the treatment effectively directs degraded organic matter toward stable, complex humic-like structures.

Multi-omics investigations, including transcriptomics and metabolomics, showed that the modified biochar stimulates fungal biofilm maturation and upregulates the expression of auxiliary activity and glycoside hydrolase genes. This molecular activation enhances extracellular enzyme activities and drives non-enzymatic Fenton-like oxidation via manganese redox cycling, producing a higher concentration of reactive hydroxyl radicals. Simultaneously, intracellular pathways governing amino acid metabolism, carbohydrate turnover, and secondary metabolite biosynthesis are upregulated, ensuring a continuous endogenous supply of phenolic and quinone precursors that fuel the polyphenol humification pathway. These outcomes provide a robust theoretical foundation for optimizing bioconversion technologies to valorize agricultural organic wastes into high-quality soil amendments.

Source: Wang, F., Zhou, F., Zhang, L., Liu, W., Su, Y., Zhang, Y., Hong, S., Zhan, M., Xie, B., & Zhou, Y. (2026). Manganese-modified biochar enhances white-rot fungi-mediated lignocellulose humification: insights from molecular transformation and multi-omics analyses. Biochar, 8, 140.