Abstract:To address the delayed heating and insufficient thermophilic phase caused by early mass transfer limitations and local oxygen shortage in aerobic composting, this study investigated the impacts of electric field intervention on the microbial ecological network and functional phenotypes. Composting experiments were conducted in 30 L reactors under different electric field intensities (0 V, 2 V, and 5 V). Physicochemical measurements, 16S rRNA-based community profiling, co-occurrence network analysis, and BugBase phenotype predictions were integrated to elucidate the coupling mechanism of electric field-microorganisms-process. The results demonstrated that electric field application markedly accelerated temperature rise and extended the thermophilic phase, with early-stage current dynamics tightly coupled to temperature. Although temporal succession remained the primary driver of microbial community structure, electric field treatments exerted significant additional effects, resulting in distinct community structures on days 7 and 18. At the genus level, electric field application enriched key taxa associated with electron transfer and fermentation (e.g., Pseudomonas, Proteiniphilum, Bacteroides, Methanocorpusculum, and Peptococcus). The network structure shifted from a “low-aggregation, short-path” pattern to a “high-aggregation, long-path” configuration, with the electric field reshaping the module affiliations and roles of dominant taxa and connectors. Weak fields promoted cross-module cooperation, whereas strong fields enhanced module compartmentalization and hub connectivity. The phenotypic level of BugBase showed periodic migration, and the 5-V electric field reshaped the bacteria to predict the phenotype spectrum effect stronger and earlier. The electric field treatment group was more inclined to enrich the phenotypes of aerobic bacteria, Gram-negative bacteria, biofilm formation, and stress tolerance, while tending to decrease Gram-positive phenotype. Collectively, the electric field enhanced microscale mass transfer and electron acceptor availability, thereby intensifying early metabolic and exothermic processes and restructuring the microbial network, achieving a state of acceleration without directional change. This study elucidates the microbial ecological mechanisms underlying electric-field regulation of aerobic composting, thereby providing a theoretical basis and technical framework for physical-field-enabled, precision modulation of microbial community functions and for the targeted optimization of composting processes.
