Effect of electric field on lactic acid and ethanol production from food waste anaerobic fermentation.

Electro-fermentation (EF) enhances product yields from food waste (FW). This study investigated the coupled effects of temperature (40 or 55 °C) and electric field (0.2-1.4 V) on ethanol and lactic acid production via anaerobic fermentation (AF). Results showed that a 1.4 V field at 40 °C (G23) boosted ethanol yield by 37.1%, while a 0.2 V field at 55 °C (G3) increased lactic acid yield by 60.3%. Notably, 0.2 V at 40 °C (G14) simultaneously enhanced both products. EF accelerated hydrolysis of polysaccharides and proteins, and modulated microbial communities, enriching key functional genera (Bacillus at 55 °C; Lactobacillus/Weissella at 40 °C). Metagenomic analysis revealed upregulated genes for ethanol dehydrogenase, lactate dehydrogenase, and NADH dehydrogenase under respective optimal conditions. This work demonstrates that tailored EF conditions can steer metabolic pathways, offering an efficient strategy for dual-bioproduct recovery from FW.