Effect of homo- and hetero-fermentative lactic acid bacteria on yeast community structure and fermentation characteristics during the silage process of Sudangrass

The overall aim of the study was to provide a theoretical basis for the improvement of the fermentation characteristics and nutritional quality of Sudangrass (Sorghum sudanense) silage. We investigated the effect of homo- and hetero-lactic acid bacteria on yeast community structure and fermentation characteristics during the silage process of Sudangrass. The control (CK) had no added inoculant; the LP group contained Lactobacillus plantarum; the LB group contained L. buchneri; and the LP + LB group contained L. plantarum and L. buchneri. All additives were added to Sudangrass and sealed in a vacuum bag. The indices of chemical characteristics, fermentation characteristic, microbial populations, and species were analyzed to evaluate the dynamic change of the yeast community and fermentation characteristics during 1, 7, 15, and 60 days. The results showed that yeast species decreased in all of the treatments during fermentation, and the number of yeast was below the limit of detection in the LB and LP + LB groups after 60 day. Compared with CK, the addition of the homo- and hetero-lactic acid bacteria can significantly decrease pH, propionic acid, butyric acid, ratio of lactic acid to acetic acid, NH₃-N, and number of yeast species, and significantly increase lactic acid and the number of lactic acid bacteria (P < 0.05). The treatment V-score was ranked in the order: LP > LP + LB > LB > CK.