The coexistence of Lactiplantibacillus and Wickerhamomyces in sugarcane top silage drives potential pathogen suppression and aerobic stability through enhanced lactic acid and acetic acid production

To identify the key coexisting bacteria and yeast in sugarcane top silage that determine fermentation quality and improve feed safety, this study reintroduced a suspension of epiphytic microorganisms from sugarcane tops after antimicrobial treatment [inhibiting epiphytic yeasts (AF) and lactic acid bacteria (AB), respectively] into fresh sugarcane tops sterilized by γ-ray irradiation for re-ensilage. Untreated (CK) and γ-ray sterilized (NA) silage served as controls. High-yield production of lactic acid and acetic acid, better aerobic stability, and high Lactiplantibacillus abundance can be achieved in both AF and CK groups. Particularly, compared to CK and NA groups, the re-establishment of Wickerhamomyces and its coexistence with the Lactiplantibacillus in AF group not only further promotes the accumulation of lactic acid and acetic acid, but reduces the potentially pathogens abundance during ensiling. Notably, Wickerhamomyces is associate with lactic and acetic acid production and potentially pathogens reduction in both AF and CK groups. Conversely, sole Wickerhamomyces presence in AB group, leads to ethanol accumulation, decreased aerobic stability, and increased potentially pathogens abundance after aerobic exposure. Moreover, the γ-hemolytic and metabolically versatile strains Wickerhamomyces anomalus G32-15 and Lactiplantibacillus plantarum G35, isolated from the well-preserved sugarcane top silage, increased the yield of lactic acid and acetic acid by co-fermenting orange peel, dragon fruit peel, and mango peel waste, respectively. This study reveals and isolates the key coexisting microorganisms for improving the fermentation quality and safety of sugarcane top silage, and provides an innovative strategy for developing microbial agents to target and regulate silage quality.