Targeted microbial acclimation and intelligent sensing of diverse livestock wastewater

Livestock wastewaters impose matrix-specific physicochemical and biological challenges on microbial fuel cell (MFC) biosensors, where uncontrolled microbial variability can affect calibration accuracy and response behavior. Here, we evaluated targeted microbial acclimation as a strategy to shape matrix-dependent anodic biofilm responses. MFC biosensors were systematically acclimated with swine (SW), cattle (CW), and a poultry-manure-derived wastewater matrix (PW) to induce matrix-dependent restructuring of anode biofilms. Following acclimation, for conditioned samples within the tested calibration range, biosensors exhibited strong linear calibration relationships (R² ≥ 0.97) across 40–280 mg L⁻¹ and improved biochemical oxygen demand (BOD) prediction accuracy, with errors of 6.93% (SW), 11.01% (CW), and 14.49% (PW), which were lower than those obtained before acclimation. Volatile fatty acid (VFA) profiles indicated distinct matrix-dependent response patterns: SW showed more extensive VFA consumption, CW showed propionate and butyrate accumulation consistent with a hydrolysis/fermentation-linked bottleneck, and PW exhibited an acetate-centered response pattern accompanied by reduced voltage at higher loading. Community clustering and network analyses further indicated matrix-associated biofilm restructuring during acclimation. These results indicate that targeted acclimation improved the BOD sensing accuracy of compact MFCs in the tested conditioned livestock-derived matrices, providing a basis for developing matrix-adapted bioelectrochemical sensors for livestock wastewater monitoring.