Lactobacillus plantarum and propionic acid improve the fermentation quality of high-moisture amaranth silage by altering the microbial community composition

Abstract

ObjectiveThe objective of this study was to determine the effect of Lactobacillus plantarum (L. plantarum) and propionic acid (PA) on the microbial community and fermentation performance of high-moisture amaranth silage.MethodsAmaranth silages were rown without addition (AhGCK) as a control and with L. plantarum JYLP-002 (AhGLP) or propionic acid (AhGPA) and then were opened after 60 days of ensiling to determine the microbial community and fermentation quality.ResultsCrude protein (CP) content, lactic acid (LA) content, and lactic acid bacteria (LAB) counts were significantly higher in AhGLP and AhGPA compared with those in AhGCK (p < 0.05). In contrast, pH, acetic acid (AA) content, and yeast and aerobic bacteria counts were significantly lower in AhGLP and AhGPA compared with those in AhGCK (p < 0.05). In addition, propionic acid (PA) levels were markedly higher in AhGPA (p < 0.05). In terms of microbial communities, the silage in the additive groups showed an increased relative abundance of Lactiplantibacillus plantarum and Lentilactobacillus buchneri and a reduced relative abundance of Enterobacter cloacae and Clostridium tyrobutyricum. The abundance of Xanthomonas oryzae was significantly increased in AhGPA, but completely inhibited in the silage supplemented with L. plantarum. Spearman’s correlation analysis revealed that Lentilactobacillus buchneri and Levilactobacillus brevis were positively associated with LA and negatively associated with pH. Conversely, Clostridium tyrobutyricum and Enterobacter cloacae were negatively associated with LA, but positively associated with pH and AA content. AA content was inversely correlated with Lentilactobacillus buchneri. Functional prediction analysis showed that LAB dominated the three groups of silage and the silages containing additives had improved carbohydrate and amino acid metabolism compared with the control silage; in particular, the AhGLP group had more heterotypic fermentation processes and a richer metabolic pathway. Furthermore, the epiphytic Lactiplantibacillus plantarum and Lentilactobacillus buchneri could inhibit the reproductive activity of undesirable microorganisms to a certain extent, thus slowing the spoilage process of the silage.ConclusionIn conclusion, L. plantarum can improve fermentation characteristics by modulating the microbial community attached to high-moisture amaranth silage and will prove useful for preserving high-moisture silage.

Effect of Compound Additives on Nutritional Composition, Fermentation Quality, and Bacterial Community of High-Moisture Alfalfa Silage

“…Harmful microorganisms (Enterobacteriaceae, Clostridium) in silage are inactivated or gradually disappear as the acidic environment in the fermentation system rapidly develops [44]. The dominant flora in all groups in this experiment were Firmicutes and Proteobacteria, which is consistent with the findings of Ogunade et al [47] and Zhang et al [48].…”

“…The low-pH environment and anaerobic conditions favor the growth of Firmicutes, which are important acid hydrolytic microorganisms that produce large amounts of extracellular enzymes under anaerobic conditions. The phylum includes the genera Lactobacillus, Lactococcus, Weissella, and Leucontos, which are the main microorganisms involved in LA fermentation [36,44], and also play a role in cellulose degradation [45]. Among them, Lactococcus usually grows vigorously and initiates LA fermentation early in silage, thus stimulating the dominance of Lactobacillus spp., while Lactobacillus spp.…”

Utilisation of Lactiplantibacillus plantarum and propionic acid to improve silage quality of amaranth before and after wilting: fermentation quality, microbial communities, and their metabolic pathway

“…Fresh amaranth was characterized by high moisture content and low water-soluble carbohydrate (WSC) content (about 2%DM). Conventional production methods, hay, may increase lignin content, resulting in amaranth leaf abscission ( Zhao et al, 2022 ). Furthermore, amaranth has a thick main stem axis and high moisture content ( Das, 2016 ), which is difficult to be dried quickly and has relatively high mold losses, resulting in its inability to produce the hay in the rainy season, whereas making it into silage allows for long term preservation while reducing the loss of nutrients.…”

Silage additives improve fermentation quality, aerobic stability and rumen degradation in mixed silage composed of amaranth and corn straw

“…Propionic acid and butyric acid can consume some of the metabolic energy during production. The conversion of lactic acid to butyric acid leads to the loss of more than half of DM content ( Zhao et al., 2022 ), which has negative effect on feed intake of animals. In the present study, mixed silage inoculated with additives significantly reduced propionic acid content.…”