Effect of lactic acid bacteria from Broussonetiapapyrifera on silage fermentation

Lactic acid bacteria (LAB) is a key factor that affects plant silage. To explore the effects of different LAB from Broussonetia papyrifera (BP) on the quality of B. papyrifera leaves (BPL), in this experiment, LAB from natural B. papyrifera (BP) silage was identified. BPL were fermented with LAB from BP as the test groups and BPL were fermented without LAB as the control group. The quality and nutritional components of BP silage were analyzed after 60 days of fermentation in the dark, to study the effects of different LAB from B. papyrifera (BP) on the quality of BPL. The results showed that four strains of LAB were isolated from the B. papyrifera silage, namely Lactobacillus sakei, Pediococcus pentosus, Enterococcus faecalis, and Weissella paramesenteroides. The first three kinds were homotypic fermentation LAB, and the last kind was a heterotypic fermentation LAB. Among them, Pediococcus pentosus and Enterococcus faecalis showed significantly better tolerance to tannins from BP than the other two strains (P < 0.05). Compared to the control group, the dry matter (DM), crude protein (CP) and soluble carbohydrates (WSC) contents of the treatment groups were significantly higher (P < 0.05). Among the treatment groups, the CP contents of Pediococcus pentosaceus and Enterococcus faecalis were significantly higher than that of the Weissella paramesenteroides group (P < 0.05). Compared to the control group, the pH and propionic acid (PA) of the treatment groups were significantly lower (P < 0.05), while the lactic acid (LA) content was significantly higher (P < 0.05). Among the treatment groups, the pH, acetic acid (AA), and ammonia nitrogen contents of Pediococcus pentosaceus and Enterococcus faecalis were significantly lower than the other groups (P < 0.05); the LA content of the Weissella paramesenteroides group was significantly lower than the other treatment groups (P < 0.05). In conclusion, the addition of exogenous LAB can improve the quality of BPL silage, and the tolerance of different LAB to BP tannins influences their enhancing effect on the quality of BPL silage fermentation.