Work

Regulatory effects of molasses on microbial community and amino acid profiles during alfalfa high-temperature fermentation

Year: 2025

Type: article

Abstract: The harvest period of alfalfa is highly concentrated in midsummer. To clarify the impact of high temperature on the fermentation process and the regulatory effect of fermentation methods on microbial community structure and amino acid metabolism, this experiment designed treatments involving fermenting alfalfa with molasses additives for 60 days under two temperature conditions: 35 °C and ambient temperature. High-temperature molasses fermentation promotes thermotolerant bacteria proliferation. Treated alfalfa's bacterial community differs sharply from fresh samples, with the most obvious changes at high temperatures. High temperature lowers Weissella 's relative abundance, but it still reproduces in molasses-rich environments. It restricts glutamine-glutamic acid interconversion, reducing most amino acids. Molasses reshapes microbiota, regulates amino acids, and better inhibits degradation at high temperatures. In conclusion, temperature alters fermented alfalfa's microbial structure and amino acid expression; molasses aids amino acid retention under high heat. • The addition of molasses under 35 °C fermentation conditions promoted the proliferation of thermotolerant bacteria by providing abundant substrates and significantly altered the microbial community structure. • High temperature inhibited the growth of Weissella , although this genus possesses a strong capacity for carbohydrate utilization. • This study attempts to clarify the microbe-metabolism interaction mechanism in high-temperature alfalfa fermentation, reveal the combined regulatory rules of high temperature and molasses, establish key association targets through integrated microbiome-metabolome analysis, and thereby enhance the depth of mechanistic interpretation of the research. • Supplementation with molasses under high-temperature fermentation conditions improved amino acid metabolism, with more pronounced effects observed at elevated temperatures compared to ambient conditions.

Source: Food Chemistry X

DOI: 10.1016/j.fochx.2025.103269