Effects of Lactiplantibacillus plantarum inoculation on the quality and bacterial community of whole-crop corn silage at different harvest stages

Abstract

Background Silage is achieved by anaerobic fermentation of lactic acid bacteria. However, harvest stage and Lactiplantibacillus plantarum (L. plantarum) content affect the changes of microbial community in silage, which play an important role in silage quality and mycotoxin levels. The current study evaluated the effects exerted by the application of L. plantarum on fermentation, mycotoxins and bacterial community of whole-crop corn silage at different harvest stages. The fresh whole plant corn from the same area was harvested during the milk stage and the dough stage, following which from each harvest stage was subjected to four L. plantarum treatments: 0 cfu/g; 1 × 106 cfu/g; 1 × 107 cfu/g; and 1 × 108 cfu/g in a 2 × 4 factorial experimental design. Samples were collected on days 0, 3, 7, 21 and 42. Subsequently, nutrition parameters, fermentation parameters, mycotoxin levels and bacterial community were determined. Results Prolonging the harvest stage resulted in an increase in the levels of starch and dry matter as well as deoxynivalenol in corn silage. Addition of 1 × 107 cfu/g and 1 × 108 cfu/g of L. plantarum applied after 42 d of ensilage reduced dry matter loss, which significantly lowered deoxynivalenol concentration in corn silage at the dough stage (P < 0.01). The pH of corn silage decreased, whereas the lactic acid concentration increased after ensiling. The effects exerted by the interaction (harvest stage × dose of L. plantarum) on pH on day 21 as well as on fermentation and lactic acid on days 21 and 42 were significant (P < 0.05). Addition of 1 × 107 cfu/g of L. plantarum at the dough stage significantly increased the relative abundance of Firmicutes while decreasing that of Bacteroidetes, compared to when L. plantarum was not added (P < 0.05). Conclusions Adding L. plantarum improved the fermentation quality and bacterial community of silage, which reduced part of mycotoxin content and relative abundance of harmful bacteria. In addition, adding L. plantarum in dough stage resulted in greater improvements to mycotoxin content and bacterial community.

Effects of lactic acid bacteria inoculants on the nutrient composition, fermentation quality, and microbial diversity of whole-plant soybean-corn mixed silage

“…Proteolysis is a critical issue in silage fermentation, with high NH 3 -N content indicating extensive protein degradation ( Tao et al, 2020 ). This study found that after 56 days of ensiling, the NH 3 -N concentration in the additive-treated silages was lower compared to CK silages, aligning with Dong et al (2022) , who reported LAB’s role in improving silage fermentation quality and reducing protein hydrolysis. The decrease in NH 3 -N content in additive-treated silage may result from the inhibition of Clostridium and other proteolytic bacteria by the low pH environment, thereby preserving the CP content ( Dong et al, 2022 ).…”

“…Consequently, WSC content is lower in the additive group than in the control group due to significant WSC consumption by LAB during fermentation. In this study, the CP contents of LP, LB, and LPB showed an increase compared to the CK group, correlating with Dong et al (2022) , who found that lower pH inhibits plant protease and microbial activities, retaining CP content.…”

Effect of isolated lactic acid bacteria on the quality and bacterial diversity of native grass silage

“…In the high DM silage such as straw forage and native grass, the water activity of LAB is insufficient, so the silage fermentation is reduced due to insufficient metabolic water required for the growth of LAB ( Borreani et al., 2018 ). Four LAB strains produced a large amount of LA and a certain amount of AA to decrease the pH and inhibit the activity of proteases in plants and microbes and reduce proteolysis using a series of substrates ( Dong et al., 2022 ; Lu et al., 2022 ). Similarly, Si et al.…”

Effects of Vachellia mearnsii Tannin Extract as an Additive on Fermentation Quality, Aerobic Stability, and Microbial Modulation of Maize Silage

“…Applying LAB inoculant (T3) on maize silage during ensiling favoured the dominancy of phylum Bacteroidetes followed by phyla Firmicutes and Proteobacteria. On the contrary, Jaipolsaen et al [48] and Dong et al [49] reported Firmicutes bacteria as the dominant phylum on maize silage treated with LAB inoculant during ensiling. However, other studies reported Proteobacteria as the dominant phylum on silage produced from different forages while treated with LAB inoculant during ensiling [20,27,41].…”