The Potential Effects on Microbiota and Silage Fermentation of Alfalfa Under Salt Stress

Abstract

This study investigated the fermentation quality of alfalfa grown in different salt stress regions in China. Following the production of silage from the natural fermentation of alfalfa, the interplay between the chemical composition, fermentation characteristics, and microbiome was examined to understand the influence of these factors on the fermentation quality of silage. The alfalfa was cultivated under salt stress with the following: (a) soil content of <1%0 (CK); (b) 1–2%0 (LS); (c) 2–3%0 (MS); (d) 3–4%0 (HS). The pH of the silage was high (4.9–5.3), and lactic acid content was high (26.3–51.0 g/kg DM). As the salt stress increases, the NA+ of the silages was higher (2.2–5.4 g/kg DM). The bacterial alpha diversities of the alfalfa silages were distinct. There was a predominance of desirable genera including Lactococcus and Lactobacillus in silage produced from alfalfa under salt stress, and this led to better fermentation quality. The chemical composition and fermentation characteristics of the silage were closely correlated with the composition of the bacterial community. Furthermore, NA+ was found to significantly influence the microbiome of the silage. The results confirmed that salt stress has a great impact on the quality and bacterial community of fresh alfalfa and silage. The salt stress and plant ions were thus most responsible for their different fermentation modes in alfalfa silage. The results of the study indicate that exogenous epiphytic microbiota of alfalfa under salt stress could be used as a potential bioresource to improve the fermentation quality.

Varieties and ensiling: Impact on chemical composition, fermentation quality and bacterial community of alfalfa

“…The PCA plots further demonstrated that the six alfalfa epiphytic microbial communities were similar before ensiling. Similar to the work of Blajman et al (2020) and Lu et al (2021) , the abundance and diversity of the bacterial community decreased after ensiling. During the ensiling process, aerobic bacteria and partly aerobic bacteria rapidly consume oxygen in the environment and create an anaerobic environment, causing inhibited metabolic activities of many microorganisms in the raw material and eventually replaced by anaerobic or facultative anaerobic bacteria such as lactic acid bacteria ( Muck et al, 2018 ).…”

“…However, in the present study, BA was not detected in the silages in both WL and XJD groups. This suggested the involvement of other bacteria in protein degradation, such as Mycobacterium , Enterococcus and Weissella ( Lu et al, 2021 ; Bao et al, 2022 ).…”

Cohort Profile: A Prospective Study of Gut Microbiota in Patients with Acute Ischemic Stroke

“…Metabolites. The fecal samples were taken for 16 s rRNA sequencing as described previously [28]. Microbial DNA was extracted and purified using QIAamp DNA Mini Kit, and then PCR amplification was carried out in the V3-V4 hypervariable region of 16 s rRNA gene.…”

Effects of growth stage on the fermentation quality, microbial community, and metabolomic properties of Italian ryegrass (Lolium multiflorum Lam.) silage

“…In order to analyze the fermentation characteristics of forage, 10 g samples of silage were combined with 90 g of deionized water and kept in a 4°C fridge for 24 h (Lu et al, 2021). The liquid extract was filtered using four layers of gauze and filter paper and used for the following analysis.…”