The objective of this study was to evaluate the effects of Lactiplantibacillus plantarum or cellulase on the fermentation characteristics and bacterial community of mixed alfalfa (Medicago sativa L., AF) and Leymus chinensis (LC) silage. The harvested alfalfa and Leymus chinensis were cut into 1–2 cm lengths by a crop chopper and they were thoroughly mixed at a ratio of 3/2 (wet weight). The mixtures were treated with no addition (CON), Lactiplantibacillus plantarum (LP, 1 × 10⁶ cfu/g fresh material), cellulase (CE, 7.5 × 10² U/kg fresh material) and their combination (LPCE). The forages were packed into triplicate vacuum-sealed, polyethylene bags per treatment and ensiled for 1, 3, 5, 7 and 30 d at room temperature (17–25 °C). Compared to the CON groups, all the additives increased the lactic acid content and decreased the pH and ammonia nitrogen content over the ensiling period. In comparison to the other groups, higher water-soluble carbohydrate contents were discovered in the CE-inoculated silages. Compared to the CON groups, the treatment with LPCE retained the crude protein content and reduced the acid detergent fiber content. The principal coordinate analysis based on the unweighted UniFrac distance showed that individuals in the AF, LC, CON and LPCE treatment could be significantly separated from each other. At the genus level, the bacterial community in the mixed silage involves a shift from Cyanobacteria_unclassified to Lactobacillus. Lactobacillus dominated in all the treatments until the end of the silage, but when added with Lactiplantibacillus plantarum, it was more effective in inhibiting undesirable microorganisms, such as Enterobacter, while reducing microbial diversity. By changing the bacterial community structure after applying Lactiplantibacillus plantarum and cellulase, the mixed silages quality could be further improved. During ensiling, the metabolism of the nucleotide and carbohydrate were enhanced whereas the metabolism of the amino acid, energy, cofactors and vitamins were hindered. In conclusion, the relative abundance of Lactobacillus in the mixed silage increased with the addition of Lactiplantibacillus plantarum and cellulase, which also improved the fermentation quality.

The study aimed to isolate, characterize, and identify wild lactic acid bacteria (LAB) strains from native grass silage on the Inner Mongolian Plateau, and the effects of wild LAB strains on the nutritive and fermentation characteristics of sorghum–sudangrass hybrid (Sorghum bicolor L. × S. sudanense L.) silage were also investigated. These isolates were evaluated using morphological, physiological, and biochemical tests. Three isolated strains were Gram‐positive, homofermentative, catalase‐negative, not produce gas from glucose, and rod‐shaped. These strains could grow normally at pH 3.5–8.0, 15–30 ˚C and NaCl 3 and 6.5%. They were identified as Lactobacillus plantarum group by sequencing 16S rRNA. Compared to uninoculated silage, all LAB‐inoculated silages significantly (P < .05) increased lactic acid (LA) content and ratios of lactic acid/acetic acid (LA/AA), while, reduced pH and ammonia nitrogen (NH₃–N). Among all the isolated LAB strains, XM2 showed the highest (P < .05) crude protein (CP), LA, ratio of LA/AA and LAB, lowest (P < .05) pH, AA, propionic acid (PA), butyric acid (BA), NH₃–N than the other isolated LAB strains. Strain XM2 is a potential starter culture for sorghum–sudangrass hybrid silage.

This study aimed to investigate the effects of Lactiplantibacillus plantarum ( L. plantarum ) or Lentilactobacillus buchneri ( L. buchneri ) on the fermentation characteristics and microbial community of oat silages in response to additives. The oat was harvested at the milk stage of maturity and was chopped into 30 mm in size. Then, the oat was treated with distilled water (control, CON treatment), L. buchneri , and L. plantarum ; the addition of L. buchneri and L. plantarum was in 1 × 106 colony-forming units/g of fresh matter and stored at room temperature (25°C). Results showed that the addition of L. plantarum inoculations could increase the lactic acid concentrations of oat silages compared with the control, and the addition of L. buchneri could increase the acetic acid concentrations, whereas the addition of L. plantarum could decrease the fiber contents and increase the crude protein content. The Shannon index of bacterial community was markedly ( P < 0.05) lower in the L. buchneri - and L. plantarum -treated oat silages, and the Shannon index of fungal community was significantly ( P < 0.05) higher in L. buchneri - and L. plantarum -treated oat silages compared with the CON treatment for 7 and 10 days of ensiling. From 7 to 90 days of ensiling, Lactobacillus was the dominant genus during the whole fermentation process in the three treatments. The homofermentative L. plantarum regulated the fermentation quality and microbial community by enhancing the Emden–Meyerhoff pathway, phosphoketolase pathway, and pentosephosphate pathway, and the heterofermentative L. buchneri modulated the ensiling performance and microbial community via improving the pentosephosphate pathway. These results suggested that the addition of lactic acid bacteria could improve the ensiling performance by regulating the microbial community in oat silage, and L. plantarum was more beneficial than L. buchneri for enhancing the fermentation quality. IMPORTANCE: Ensiled whole-plant oats are an important feedstuff for ruminants in large parts of the world. Oat silage is rich in dietary fibers, minerals, vitamins, and phytochemicals beneficial to animal health. The fermentation of oat silage is a complex biochemical process that includes interactions between various microorganisms. The activity of many microbes in silage may cause an extensive breakdown of nutrition and lead to undesirable fermentation. Moreover, it is difficult to make high-quality oat silage because the number of epiphytic lactic acid bacterium microflora was lower than the requirement. Understanding the complex microbial community during the fermentation process and its relationship with community functions is therefore important in the context of developing improved fermentation biotechnology systems. These results suggested that the addition of Lactobacillus plantarum or Lactobacillus buchneri regulated the ensiling performance and microbial community in oat silage by shaping the metabolic pathways.

Ensiling technology shows promise for preserving and providing high-quality forage. However, the high polymeric content and compact properties of fiber result in low biodigestibility. This study aimed to evaluate the use of ensiling technology for storing wheat straw. It also analyzed changes in fermentation-related products, chemical components, bacterial communities, and metabolite profiles of wheat straw ensiled with or without cellulase or Lactiplantibacillus plantarum (L. plantarum). The results showed that inoculation with L. plantarum, either alone or with cellulase, produced abundant organic acids, degraded fiber, suppressed most microbes, and increased certain metabolites in wheat straw silage. Wheat straw inoculated with L. plantarum, either alone or with cellulase, exhibited significantly lower neutral detergent fiber and acid detergent fiber contents compared to the control treatment. Additionally, higher lactic acid and acetic acid contents were observed in these treatments. The microbiome analysis revealed that Lactobacillus was dominant, while Kosakonia was suppressed. Metabolic analysis showed a significant increase in amino acids, peptides, analogues, and organic acid derivatives. Overall, wheat straw inoculated with L. plantarum, either alone or with cellulase, produced well-preserved silage, providing new insights into recycling and utilizing wheat straw through bacterial-enzyme synergy.

Most oat forage has low water-soluble carbohydrates (WSC), which may be the main limited factor for silage fermentation safely, but oat is rich in cellulose and hemicellulose; therefore, we assume that xylanase and cellulase as additives can reduce the content of cellulose and xylan in oat silage, increase the microbial fermentable sugar content, and improve the fermentation quality of the silage. After wilting, oats were treated as follows: (i) distributed water (CK); (ii) silages inoculated with xylanase (X); (iii) silages inoculated with cellulase (C), ensiling for 3 days (early stage of silage) and 60 days (late stage of silage), respectively, after ensiling 60 days for a 5-day aerobic exposure study. The pH, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were significantly reduced by xylanase and cellulase treatment during the late stage of silage, and the concentration of lactic acid, acetic acid, and ammonia nitrogen increased remarkably. The WSC content reached its peak with xylanase treatment during the late stage of silage. The content of crude protein (CP) was not affected by additives but by the silage period; CP and ether extract (EE) significantly increased during the late stage of silage compared to the early stage. After ensiling, the bacterial community showed that xylanase and cellulase treatment increased the relative abundance of lactic acid bacteria. Lactobacillus has a higher relative abundance with cellulase treatment after 60 days of ensiling; this can effectively reduce the pH of silage and ensure long-term, stable storage of silage. Cellulase and xylanase increased bacterial diversity during aerobic exposure and improved the aerobic stability of silage significantly. This study indicated that different additives and silage periods had significant effects on chemical compositions, fermentation quality, and bacterial community; meanwhile, both additives improved the aerobic stability of silage. In summary, when the WSC of oat is low, cellulase and xylanase have good effects as silage additives, and the comprehensive effect of cellulase is more prominent.