Effect of Fenton-like reactions on the hydrolysis efficiency of lignocellulose during rice straw composting based on genomics and metabolomics sequencing

The purposes of this study were to explore the effect of Fenton-like reactions on the hydrolysis efficiency of lignocellulose and the formation mechanism of humic substance (HS) during rice straw composting based on genomics and metabolomics sequencing. The inoculation of Aspergillus fumigatus and adding Fe (II) into compost were used to establish Fenton-like reactions. Fenton-like reactions have been successfully established in vitro and in the composting process. In addition, Fenton-like reactions increased HS and humic acid concentration by 96.38% and 255.80%, respectively, further promoting the humification process. The key differential lignocellulose-degrading products in the Fenton-like reactions, especially for maltose, glucose, xylose, galactose, phenols, butyrophenone, vanillin, syringe acid, vanillic acid hydroxycinnamic acid and benzoic acid, were identified. Additionally, network analysis was divided into four modular microbes in the fungal network. The functional fungal modules' functions and their related influencing factors showed essential roles in the hydrolysis efficiency of lignocellulose and HS formation during composting. This research provides new insight into the hydrolysis efficiency of lignocellulose and then promotes the formation of HS in the Fenton-like reactions during agricultural waste composting.