Multi-omics insights into the regulation mechanism of citric acid in silage fermentation

This study found that CA supplementation altered silage microbial composition and function, which increased the abundance of lactic acid-rods (Levilactobacillus, Lentilactobacillus, Companillactobacillus), and inhibited the abundance of lactic acid-cocci (Leuconostoc, Pediococcus, Weissella) and undesirable bacteria (Acinetobacter, Serratia, Klebsiella, Pantoea), resulting in increasing the abundance of genes involved in structural carbohydrate hydrolysis (cellulase, pectinase), lactic acid production (ldh) and amino acid synthesis (CKase, CPS1), and decreasing the abundance of genes involved in acetic acid production (porA, acs, pdhC, pct), NH3 production (glsA) and antibiotic resistance. Accordingly, CA supplementation could improve the nutritional value, preservation, and biosafety of silage by regulating its microbial composition and function.