An Evaluation of the Effectiveness of a Chemical Additive on the Fermentation Quality, Aerobic Stability and Microbial Communities of High-Moisture Corn at 35 °C and 5 °C

This study evaluated a compound chemical additive (CA) composed of potassium sorbate, sodium benzoate, and sodium nitrite. Potassium sorbate is suitable for high-temperature ensiling, while sodium nitrite functions well under low-temperature conditions, and sodium benzoate inhibits bacterial energy metabolism. This compound theoretically provides stable antibacterial effects across variable storage temperatures. The effects of CA on fermentation quality, aerobic stability, and microbial communities of high-moisture corn (HMC) silage were investigated at 35 °C and 5 °C, including the control group (CON) and CA group. After 28 days of fermentation and 7 days of aerobic exposure, microbial communities were analyzed via high-throughput sequencing. CA significantly improved silage quality at both temperatures, increasing lactic acid and crude protein content, reducing pH, NH3-N and neutral detergent fiber, and suppressing yeasts and enterobacteria to enhance aerobic stability. Storage temperature dominated microbial community composition, while CA further optimized microbial structure. At 35 °C, CA eliminated spoilage yeast Nakaseomyces glabratus and enriched Levilactobacillus brevis and Aspergillus spp. with elevated relative abundance. At 5 °C, CA inhibited cold-resistant spoilage microbes, promoted the accumulation of Latilactobacillus curvatus, and restricted cyanobacteria growth. Metabolic prediction indicated that CA was correlated with pathways related to enhanced lactic acid synthesis and inhibited proteolysis and silage spoilage. In conclusion, CA effectively stabilizes HMC silage by regulating microbial and metabolic characteristics under different temperatures, serving as a promising temperature-adaptive preservative.