Construction of Multifunctional Microbial Inoculants for Lignocellulosic Degradation and Their Effects on Straw...

The efficient biodegradation of lignocellulosic biomass is a critical challenge and opportunity in sustainable agriculture and waste management. This study initially screened lignocellulose-degrading fungi and integrated them with biosurfactant-producing microbes and organic matter-transforming microbes to obtain a multifunctional lignocellulosic-degrading microbial agent (MLDM). Then, the effects of MLDM on straw degradation were analyzed by setting up a control check (CK), commercially available microbial agents (CAM), and MLDM. Results showed that the MLDM group had higher lignocellulose-degrading enzyme activity, enabling the most effective straw degradation. Compared with the CK and CAM groups, the straw weight loss, hemicellulose, cellulose, and lignin degradation rates in the MLDM were higher at 40.93% and 12.80%, 43.46% and 15.12%, 77.43% and 30.92%, and 75.49% and 13.20%, respectively. At the end of the experiment, the C/N ratio in the MLDM group was 18.98, and the humic acid and fulvic acid ratio reached 2.34, indicating enhanced maturity and stability. Structural characterization by FTIR and XRD revealed that MLDM treatment was associated with reduced cellulose crystallinity and altered chemical bond profiles, while SEM imaging showed more severe surface disruption of straw, consistent with accelerated degradation. Microbial community analysis indicated that MLDM inoculation increased the abundance of key degradative genera (e.g., Bacillus and Saccharomycetales). Functional predictions suggested that MLDM enhanced microbial metabolic pathways related to carbohydrate and amino acid metabolism. The lignocellulose-degradation effect of MLDM enhances the biotransformation efficiency of agricultural waste, providing new strategies for straw waste management.