State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
Probiotics and Biological Feed Research Center, Lanzhou University, Lanzhou, 730000, China.
Appl Microbiol Biotechnol. 2024 Mar 8;108(1):257. doi: 10.1007/s00253-024-13096-4.
Sorghum forage was ensiled for 90 days at two dry matter (DM) contents (27 vs. 39%) without or with Lactiplantibacillus plantarum inoculation. On day 90 of fermentation, silages were sampled to assess the microbial community dynamics and metabolome profile. L. plantarum inoculation improved silage quality, as shown by a lower pH and greater acetic acid concentration. Loss of DM remained unaffected by L. plantarum inoculation but was greater in low- vs. high-DM sorghum silages (14.4 vs. 6.62%). The microbiome analysis revealed that Pseudomonas congelans represented the dominant species of the epiphytic microbiota in both low- and high-DM sorghum forage before ensiling. However, L. buchneri represented the dominant species at the end of ensiling. Ensiling fermentation resulted in distinct metabolic changes in silages with varying DM content. In low-DM silages, ensiling fermentation led to the accumulation of 24 metabolites and a reduction in the relative concentration of 13 metabolites. In high-DM silages, ensiling fermentation resulted in an increase in the relative concentration of 26 metabolites but a decrease in the concentration of 8 metabolites. Compared to non-inoculated silages, L. plantarum inoculation resulted in an increased concentration of 3 metabolites and a reduced concentration of 5 metabolites in low-DM silages. Similarly, in high-DM silages, there was an elevation in the relative concentration of 3 metabolites, while a decrease in 7 other metabolites. Ten metabolites with bio-functional activity were identified, including chrysoeriol, isorhamnetin, petunidin 3-glucoside, apigenin, caffeic acid, gallic acid, p-coumaric acid, trans-cinnamic acid, herniarin, and 3,4-dihydroxy-trans-cinnamate. This study presents a comprehensive analysis of microbiome and metabolome profiling of sorghum forage during ensiling as a function of DM content and L. plantarum inoculation, with a particular emphasis on identifying metabolites that may possess bio-functional properties. KEY POINTS: • DM loss was not different by L. plantarum but higher in low- vs. high-DM silage. • L. buchneri dominated ensiling, regardless of DM level. • 10 metabolites with bio-functional activity were identified.
高粱青贮在 27%和 39%两种干物质（DM）含量下分别不添加和添加植物乳杆菌（Lactiplantibacillus plantarum）进行青贮 90 天。发酵第 90 天，取样评估微生物群落动态和代谢组特征。与不添加 L. plantarum 相比，添加 L. plantarum 提高了青贮品质，表现为 pH 值更低，乙酸浓度更高。无论添加 L. plantarum 与否，DM 损失不受影响，但在低 DM 和高 DM 高粱青贮中损失更大（14.4%对 6.62%）。微生物组分析表明，在青贮前低 DM 和高 DM 高粱饲料的附生微生物群中，凝结芽胞杆菌（Pseudomonas congelans）是优势种。然而，在青贮结束时，布赫纳氏菌（L. buchneri）是优势种。青贮发酵导致 DM 含量不同的青贮饲料中产生了明显不同的代谢变化。在低 DM 青贮中，青贮发酵导致 24 种代谢物积累，13 种代谢物相对浓度降低。在高 DM 青贮中，青贮发酵导致 26 种代谢物相对浓度增加，但 8 种代谢物浓度降低。与未接种青贮相比，添加 L. plantarum 使低 DM 青贮中 3 种代谢物浓度增加，5 种代谢物浓度降低。同样，在高 DM 青贮中，3 种代谢物的相对浓度升高，而另外 7 种代谢物的浓度降低。鉴定出 10 种具有生物功能活性的代谢物，包括芹菜素、异鼠李素、天竺葵苷 3-葡萄糖苷、芹菜素、咖啡酸、没食子酸、对香豆酸、反式肉桂酸、瑞香素、3,4-二羟基反式肉桂酸。本研究全面分析了高粱青贮作为 DM 含量和添加植物乳杆菌（Lactiplantibacillus plantarum）的函数，对青贮过程中微生物组和代谢组的动态变化进行了研究，特别强调了鉴定具有生物功能特性的代谢物。关键点： • 无论 DM 水平如何，添加植物乳杆菌对 DM 损失没有影响，但在低 DM 青贮中损失更大。 • 无论 DM 水平如何，布赫纳氏菌（L. buchneri）都是青贮的优势种。 • 鉴定出 10 种具有生物功能活性的代谢物。
