Ginkgo fruit extract as an additive to modify rumen microbiota and fermentation and to mitigate methane production
Ginkgo fruit extract as an additive to modify rumen microbiota and fermentation and to mitigate methane production
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DOI：
10.3168/jds.2016-11928
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发表时间：
2017-03-01
影响因子：
3.5
通讯作者：
Kobayashi, Y.
中科院分区：
文献类型：
--
作者：
Oh, S.;Shintani, R.;Kobayashi, Y.
银杏果是银杏坚果工业的一种未使用的副产品，含有被称为漆树酸的抗菌化合物。本文对银杏的两个主要栽培品种Kyuju（K）和Tokuro（T）作为反刍动物饲料添加剂的潜力进行了评价。在分批培养中，我们孵育干草和浓缩物的混合物在稀释瘤胃液与或不与1.6%（水果当量）银杏果实提取物。我们进行了另一系列的分批培养研究，以确定发酵的剂量反应。我们还进行了连续培养，利用瘤胃模拟技术（RUSITEC）与品种K和进行了纯培养研究，以监测17个代表性的瘤胃细菌物种的敏感性银杏提取物和组分酚。虽然K和T提取物都导致甲烷减少和丙酸产量增加，但K提取物的变化更明显，并且具有剂量依赖性。总产气量在>= 3.2%的剂量下被抑制，表明1.6%是最佳的补充水平。在RUSITEC发酵补充1.6%银杏K，甲烷减少了53%，而不影响总气体或总VFA生产，但减少乙酸和增加丙酸。干物质、中性洗涤纤维和酸性洗涤纤维的消失不受银杏的影响，但氨水平降低。定量PCR结果表明，与产氢和产甲酸相关的原生动物、真菌、产甲烷菌和细菌的丰度下降，而与产丙酸相关的细菌的丰度增加。MiSeq分析（Illumina Inc.，San Diego，CA）证实了这些细菌变化，并鉴定了古细菌群落变化，包括甲烷短杆菌和甲烷微球菌科的减少以及甲烷扁菌的增加。纯培养研究结果支持上述细菌群落变化的发现。这些结果表明，银杏果可以调节瘤胃发酵甲烷减少和丙酸通过微生物的选择提高。
Ginkgo fruit, an unused byproduct of the ginkgo nut industry, contains antimicrobial compounds known as anacardic acids. Two major cultivars of ginkgo, Kyuju (K) and Tokuro (T), were evaluated for their potential as a feed additive for ruminants. In batch culture, we incubated a mixture of hay and concentrate in diluted rumen fluid with or without 1.6% (fruit equivalent) ginkgo fruit extract. We conducted another series of batch culture studies to determine the dose response of fermentation. We also conducted continuous culture using the rumen simulation technique (RUSITEC) with cultivar K and carried out a pure culture study to monitor the sensitivity of 17 representative rumen bacterial species to ginkgo extract and component phenolics. Although both K and T extracts led to decreased methane and increased propionate production, changes were more apparent with K extract, and were dose-dependent. Total gas production was depressed at doses >= 3.2%, suggesting that 1.6% was the optimal supplementation level. In RUSITEC fermentation supplemented with 1.6% ginkgo K, methane decreased by 53% without affecting total gas or total VFA production, but with decreased acetate and increased propionate. Disappearance of dry matter, neutral detergent fiber, and acid detergent fiber were not affected by ginkgo, but ammonia levels were decreased. Quantitative PCR indicated that the abundance of protozoa, fungi, methanogens, and bacteria related to hydrogen and formate production decreased, but the abundance of bacteria related to propionate production increased. MiSeq analysis (Illumina Inc., San Diego, CA) confirmed these bacterial changes and identified archaeal community changes, including a decrease in Methanobrevibacter and Methanomassiliicoccaceae and an increase in Methanoplanus. Pure culture study results supported the findings for the above bacterial community changes. These results demonstrate that ginkgo fruit can modulate rumen fermentation toward methane mitigation and propionate enhancement via microbial selection.