Zhang Zhenwei, Wang Yanlu, Si Xuemeng, Cao Zhijun, Li Shengli, Yang Hongjian
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Animals (Basel). 2020 Mar 13;10(3):479. doi: 10.3390/ani10030479.
Nitroethane (NE), 2-nitroethanol (NEOH), and 2-nitro-1-propanol (NPOH) were comparatively examined to determine their inhibitory actions on rumen fermentation and methanogenesis in vitro. Fermentation characteristics, CH and total gas production, and coenzyme contents were determined at 6, 12, 24, 48, and 72 h incubation time, and the populations of ruminal microbiota were analyzed by real-time PCR at 72 h incubation time. The addition of NE, NEOH, and NPOH slowed down in vitro rumen fermentation and reduced the proportion of molar CH by 96.7%, 96.7%, and 41.7%, respectively ( < 0.01). The content of coenzymes F and F and the relative expression of the A gene declined with the supplementation of NE, NEOH, and NPOH in comparison with the control ( < 0.01). The addition of NE, NEOH, and NPOH decreased total volatile fatty acids (VFAs) and acetate ( < 0.05), but had no effect on propionate concentration ( > 0.05). Real-time PCR results showed that the relative abundance of total methanogens, , and were reduced by NE, NEOH, and NPOH ( < 0.05). In addition, the nitro-degradation rates in culture fluids were ranked as NEOH (-0.088) > NE (-0.069) > NPOH (-0.054). In brief, the results firstly provided evidence that NE, NEOH, and NPOH were able to decrease methanogen abundance and dramatically decrease A gene expression and coenzyme F and F contents with different magnitudes to reduce ruminal CH production.
对硝基乙烷（NE）、2-硝基乙醇（NEOH）和2-硝基-1-丙醇（NPOH）进行了比较研究，以确定它们对体外瘤胃发酵和甲烷生成的抑制作用。在培养6、12、24、48和72小时时测定发酵特性、CH和总气体产量以及辅酶含量，并在培养72小时时通过实时PCR分析瘤胃微生物群的数量。添加NE、NEOH和NPOH减缓了体外瘤胃发酵，并分别使甲烷的摩尔比例降低了96.7%、96.7%和41.7%（<0.01）。与对照组相比，添加NE、NEOH和NPOH后辅酶F和F的含量以及A基因的相对表达下降（<0.01）。添加NE、NEOH和NPOH降低了总挥发性脂肪酸（VFA）和乙酸盐含量（<0.05），但对丙酸盐浓度没有影响（>0.05）。实时PCR结果表明，NE、NEOH和NPOH降低了总产甲烷菌、 、 和 的相对丰度（<0.05）。此外，培养液中的硝基降解率排序为NEOH（-0.088）>NE（-0.069）>NPOH（-0.054）。简而言之，结果首次提供了证据，表明NE、NEOH和NPOH能够降低产甲烷菌丰度，并显著降低A基因表达以及辅酶F和F的含量，且降低幅度不同，从而减少瘤胃CH的产生。
