Chain elongation of food waste to medium-chain fatty acids without exogenous electron donors: RBO dominance and toxicity-threshold effect
Lipid-rich food waste (FW), containing abundant triglycerides, free fatty acids, and long-chain fatty acids, has great potential for resource recovery through anaerobic fermentation to produce value-added products. However, the high lipid content often causes substrate toxicity and process instability, which hinder the efficient synthesis of medium-chain fatty acids (MCFAs). To elucidate the metabolic mechanisms of MCFA formation under high-lipid conditions, a two-stage anaerobic chain-elongation (CE) system without exogenous electron donors was established using the liquid fraction of FW as the sole substrate.