Microbial Community Restructuring Enhances Composting Efficiency: Synergistic Roles of Thermal Cycling and Fungal Inoculants ( Fomes lignosus and Penicillium glabrum ) in Metabolic Adaptation

This study demonstrates that synergistic integration of thermal cycling (28°C-58°C) and fungal inoculants (Fomes lignosus, Penicillium glabrum) enhances humification in cattle manure composting by restructuring microbial communities toward metabolic adaptation. Through a temperature-phased aerobic system, both inoculants significantly improved carbon conversion efficiency, with F. lignosus (B) and P. glabrum (G) increasing total organic matter by 4.71% and 3.42% (vs. control), humic acid content by 4.58-fold and 2.35-fold, and FDA hydrolase activity by 3.28-fold and 1.22-fold, respectively, confirming improved humification and nutrient cycling. Temperature-inoculant synergy drove functional differentiation. Respiratory profiling revealed that P. glabrum enhanced oxygen consumption by 1.3-fold during the early thermophilic phase (0-168 h at 58°C). Subsequently, temperature-induced respiration hierarchies (control > B > G) converged over time with microbial domestication. High-throughput sequencing and network analyses revealed that temperature-inoculant synergy reshaped the microbiome into simplified consortia, which comprise seven dominant bacterial phyla (e.g., Firmicutes, Actinobacteriota) and three dominant fungal phyla (e.g., Ascomycota), with marked functional differentiation characteristics. P. glabrum selectively enriched humification-related taxa, providing regulatory strategies for enhanced carbon stabilization; whereas F. lignosus favoured lignocellulose-degrading communities, optimising substrate valorisation efficiency. This strategy establishes a targeted microbial framework for optimising the resource utilisation efficiency of lignocellulosic waste within fermentation systems, thereby contributing to circular bioeconomy goals in sustainable organic waste management.