Exploring the influence of moisture stress on microbial-driven organic acid synthesis in potato waste fermentation

Anaerobic fermentation of potato leaves and stems for organic acid synthesis, serving as food additives , faces impediments due to misconceptions about the effects of moisture stress on the acid-synthesizing microbiome . An ingenious method, avoiding interference from microbiome and nutrient integrations, was employed in the present study. Results showed that increasing the moisture level from 60 % to 75 % significantly improved lactic acid (182.64 %), acetic acid (163.55 %), propionic acid (1960.43 %), nonprotein nitrogen , free amino acid and ammonia levels but reduced pH value and water-soluble carbohydrate and hemicellulose levels. Microbiologically, the high-moisture groups enriched Lactiplantibacillus , Levilactobacillus and Enterobacter , upregulated glycolysis, nitrogen, pyruvate and propanoate metabolisms, and activated genes for acid-producing and ammonia-forming enzymes . Notably, Lactiplantibacillus and Enterobacter prevailed in glycolysis and nitrogen metabolism , respectively, and Levilactobacillus was more prominent in pyruvate and propanoate metabolism under high-moisture conditions. Collectively, a moisture level of 75 % benefited organic acid synthesis from potato waste via anaerobic fermentation.