Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol-An in vitro evaluation
Effects on enteric methane production and bacterial and archaeal communities by the addition of cashew nut shell extract or glycerol-An in vitro evaluation
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DOI：
10.3168/jds.2014-7929
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发表时间：
2014-09-01
影响因子：
3.5
通讯作者：
Bertilsson, Jan
中科院分区：
文献类型：
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作者：
Danielsson, Rebecca;Werner-Omazic, Anna;Bertilsson, Jan
本研究的目的是评价腰果壳提取物（CNSE）和甘油（纯度bbb99 %）在体外自动气体系统中对肠道甲烷（CH4）产生和微生物群落的影响。将体外系统的微生物群落与供体奶牛的体内样品进行比较。将接种的瘤胃液与粗精比为60:40的饲粮混合，共设置5个不同处理：CNSE 5 mg （CNSE-L）、CNSE 10 mg （CNSE- h）、甘油15 mmol /L（甘油-L）、甘油30 mmol /L（甘油- h），不添加饲料添加剂。在孵育2、4、8、24、32、48 h时取气样，测定CH4浓度。孵育8、24和48 h后，取瘤胃液样品进行挥发性脂肪酸分析和微生物序列分析。连续3天，在奶牛晨饲后2 h采集体内瘤胃标本，比较体外系统与体内条件。采用混合模型和主成分分析对天然气数据和微生物序列分析（454测序）数据进行了分析。这些分析表明，对于L和H浓度，CNSE处理使CH4产量分别降低了8%和18%。相反，在L和H浓度下，甘油分别使CH4产量增加8%和12%。CNSE的抑制作用可能是由于观察到细菌种群的变化，可能导致产甲烷底物氢或甲酸酯的产量减少。或者，这种反应可以用产甲烷群落的变化来解释。在甘油处理中，与体内对照相比，细菌和古细菌数量没有明显差异。因此，CH4产量的增加可以通过体外系统中底物的增加来解释。体外添加CNSE降低了奶牛瘤胃CH4的产量，表明CNSE可能是一种很有前景的CH4抑制剂。
The objective of the study was to evaluate the effect of cashew nut shell extract (CNSE) and glycerol (purity >99%) on enteric methane (CH4) production and microbial communities in an automated gas in vitro system. Microbial communities from the in vitro system were compared with samples from the donor cows, in vivo. Inoculated rumen fluid was mixed with a diet with a 60:40 forage:concentrate ratio and, in total, 5 different treatments were set up: 5 mg of CNSE (CNSE-L), 10 mg of CNSE (CNSE-H), 15 mmol of glycerol/L (glycerol-L), and 30 mmol of glycerol/L (glycerol-H), and a control without feed additive. Gas samples were taken at 2, 4, 8, 24, 32, and 48 h of incubation, and the CH4 concentration was measured. Samples of rumen fluid were taken for volatile fatty acid analysis and for microbial sequence analyses after 8, 24, and 48 h of incubation. In vivo rumen samples from the cows were taken 2 h after the morning feeding at 3 consecutive days to compare the in vitro system with in vivo conditions. The gas data and data from microbial sequence analysis (454 sequencing) were analyzed using a mixed model and principal components analysis. These analyses illustrated that CH4 production was reduced with the CNSE treatment, by 8 and 18%, respectively, for the L and H concentration. Glycerol instead increased CH4 production by 8 and 12%, respectively, for the L and H concentration. The inhibition with CNSE could be due to the observed shift in bacterial population, possibly resulting in decreased production of hydrogen or formate, the methanogenic substrates. Alternatively the response could be explained by a shift in the methanogenic community. In the glycerol treatments, no main differences in bacterial or archaeal population were detected compared with the in vivo control. Thus, the increase in CH4 production may be explained by the increase in substrate in the in vitro system. The reduced CH4 production in vitro with CNSE suggests that CNSE can be a promising inhibitor of CH4 formation in the rumen of dairy cows.