Dynamics of bacterial community and fermentation quality of wheat straw silage treated with lactic acid bacteria and/or sucrose

Abstract

This study aimed to investigate the impact of lactic acid bacteria and sucrose on the bacterial community dynamics and fermentation quality of wheat straw silage. Wheat straw was chopped into 1–2 cm pieces, moistened to 60 %, and ensiled with no additives (CK), Lactiplantibacillus plantarum (L, 1 × 10⁵ colony-forming units/g fresh weight), sucrose (S, 1 % fresh weight), or their combination (LS). The silages were stored at room temperature and sampled at 1, 3, 6, 15, 35, and 150 days. The S treatment exhibited higher concentrations of lactic acid (LA), acetic acid (AA), and ammonia nitrogen (AN) between days 15 and 35 compared to other treatments. Lactobacillaceae predominated in the CK and L treatments from days 3–35, while Lactobacillaceae-noname became the dominant group by day 150. In contrast, Pantoea remained the dominant genus throughout the fermentation period in the S and LS treatments. Additionally, Enterobacteriaceae abundance fluctuated significantly during fermentation. The abundance of lactic acid bacteria was positively correlated with lactic acid and acetic acid concentrations, and negatively correlated with pH. In conclusion, the addition of Lactiplantibacillus plantarum and sucrose to wheat straw silage improved both the microbial community structure and fermentation quality, providing new strategies for agricultural waste utilization.