Complementary TCA cycle precursor supply enhances ammonia assimilation and nitrogen retention during vegetable waste composting.

Supplementing vegetable waste composting with combined citric and pyruvic acid precursors reduces ammonia emissions by up to 76% and enhances nitrogen retention by over 25%.

• Why it matters: Reactive nitrogen loss hampers nutrient recovery and environmental sustainability in organic waste composting, necessitating strategies to improve nitrogen retention and reduce emissions.
• What they did: The study applied citric acid and pyruvic acid, alone and combined, as TCA cycle precursors in composting, maintaining consistent carbon input and pH, and analyzed metabolite profiles, gene abundance, enzyme activity, and microbial succession.
• The result: The combined precursor treatment optimized ammonia assimilation pathways, increased organic nitrogen and humic substances, and decreased ammonia volatilization, offering a metabolic strategy to improve nutrient recovery in composting systems.