中文摘要：将含有84.5g / kg缩合单宁（CT）干燥物质（DM）的紫色草原三叶草（PPC; Dalea purpurea Vent.）在无（对照）或用聚乙二醇（PEG）的情况下青贮76天，然后进行14天的有氧暴露。确定发酵特征的变化，并使用宏基因组测序评估细菌和真菌群落的组成。在青贮时添加聚乙二醇（PEG）使CT失活后，可溶性氮，非蛋白氮，乳酸，总挥发性脂肪酸，氨氮，脱氧雪腐镰刀菌烯醇（DON）和赭曲霉毒素A（OTA） 增加（P <0.05，相似于0.001），但pH和水溶性碳水化合物降低（P <0.001）。两种青贮饲料中DON和OTA的浓度均有增加（P <0.001），对照组的增加程度大于有氧暴露过程中经过PEG处理的青贮饲料。与对照相比，PEG处理的青贮饲料显示出更高（P <0.01至<0.001）的细菌总数，乳杆菌，酵母菌和真菌的拷贝数。在青贮和有氧暴露过程中，PEG的添加降低（P <0.01）细菌多样性，而在有氧暴露期间添加PEG增加（P <0.05）真菌多样性。在青贮饲料中添加PEG增加了（P <0.05）乳杆菌和片球菌属的丰度，但降低了（P <0.01）乳球菌和明串珠菌属的丰度。在青贮期和有氧暴露后在微生物组中发现丝状真菌，而芽孢杆菌属是有氧暴露后的主要细菌。总之，CT降低了蛋白质降解并改善了青贮饲料的有氧稳定性。这些理想的结果可能反映了PPC CT抑制那些降低青贮饲料质量和产生霉菌毒素的微生物的能力。重要性 本研究报告了缩合单宁对紫色草原三叶草青贮和有氧暴露过程中产生的复杂微生物群落的影响。该研究记录了缩合单宁降低霉菌毒素产生和相关微生物组的能力。发酵后的分类细菌群落分布以乳杆菌为主，由于有氧接触，芽孢杆菌属显著增加。有趣的是观察到缩合单宁在青贮和有氧暴露期间减少了细菌多样性，但仅在有氧暴露期间增加了真菌多样性。本研究表明，缩合单宁对微生物群落的影响导致青贮末期乳酸和总挥发性脂肪酸的产生、蛋白质水解和霉菌毒素浓度的降低，并改善了有氧稳定性。缩合单宁可作为一种添加剂，用于控制不利微生物发育，并可能提高饲料安全性。
外文摘要：Purple prairie clover (PPC; Dalea purpurea Vent.) containing 84.5 g/kg dry matter (DM) of condensed tannin (CT) was ensiled without (control) or with polyethylene glycol (PEG) for 76 days, followed by 14 days of aerobic exposure. Changes in fermentation characteristics were determined, and the composition of bacterial and fungal communities were assessed using metagenomic sequencing. The addition of polyethylene glycol (PEG) that deactivated CT at ensiling increased (P < 0.05 to similar to 0.001) soluble N, nonprotein N, lactic acid, total volatile fatty acids, ammonia N, deoxynivalenol (DON), and ochratoxin A (OTA) but decreased (P < 0.001) pH and water-soluble carbohydrates. The concentrations of DON and OTA increased (P < 0.001) for both silages, with the extent of increase being greater for control than for PEG-treated silage during aerobic exposure. The PEGtreated silage exhibited higher (P < 0.01 to < 0.001) copy numbers of total bacteria, Lactobacillus, yeasts, and fungi than the control. The addition of PEG decreased (P < 0.01) bacterial diversity during both ensiling and aerobic exposure, whereas it increased (P < 0.05) fungal diversity during aerobic exposure. The addition of PEG at ensiling increased (P < 0.05) the abundances of Lactobacillus and Pediococcus species but decreased (P < 0.01) the abundances of Lactococcus and Leuconostoc species. Filamentous fungi were found in the microbiome at ensiling and after aerobic exposure, whereas Bacillus spp. were the dominate bacteria after aerobic exposure. In conclusion, CT decreased protein degradation and improved the aerobic stability of silage. These desirable outcomes likely reflect the ability of PPC CT to inhibit those microorganisms involved in lowering silage quality and in the production of mycotoxins.IMPORTANCE The present study reports the effects of condensed tannins on the complex microbial communities involved in ensiling and aerobic exposure of purple prairie clover. This study documents the ability of condensed tannins to lower mycotoxin production and the associated microbiome. Taxonomic bacterial community profiles were dominated by Lactobacillales after fermentation, with a notable increase in Bacillus spp. as a result of aerobic exposure. It is interesting to observe that condensed tannins decreased bacterial diversity during both ensiling and aerobic exposure but increased fungal diversity during aerobic exposure only. The present study indicates that the effects of condensed tannins on microbial communities lead to reduced lactic acid and total volatile fatty acid production, proteolysis, and mycotoxin concentration in the terminal silage and improved aerobic stability. Condensed tannins could be used as an additive to control unfavorable microbial development and maybe enhanced feed safety
外文关键词：bacteria；condensed tannins；fungi；purple prairie clover；silage
作者：Peng, Kai；Jin, Long；Niu, Yan D.；等
作者单位：Agriculture & Agri Food Canada
期刊名称：APPLIED AND ENVIRONMENTAL MICROBIOLOGY
期刊影响因子：3.633
出版年份：2018
出版刊次：5
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