不同添加量3-NOP对体外瘤胃发酵甲烷产量及甲烷菌区系的影响

Effect of different levels of 3-NOP on methane production and methanogens community by in vitro fermentation

试验旨在通过体外瘤胃发酵法研究高精料饲粮中添加不同剂量3-硝基酯-1-丙醇(3-NOP)对甲烷产量及甲烷菌区系的影响。采用完全随机区组设计,共设4组,对照组(C组)、低剂量组(LD组)、中剂量组(MD组)、高剂量组(HD组),分别向发酵底物中添加0、0.4、0.8、1.2 mg 3-NOP。体外发酵培养24 h。结果表明,与对照组相比,各3-NOP处理组瘤胃甲烷产量和每克可降解底物的甲烷产量均显著降低(P<0.05),但氢气产量和每克可降解底物的氢气产量显著增加(P<0.05)。HD组瘤胃干物质降解率显著低于其他组(P<0.05),每克可降解底物总产气量显著高于其他组(P<0.05)。与对照组和LD组相比,MD组瘤胃发酵Simspon指数显著降低(P<0.05)。各3-NOP处理组瘤胃甲烷球形菌属(Methanosphaera)的相对丰度显著低于对照组。研究表明,3-NOP通过对甲烷菌甲基辅酶M还原酶的特异性抑制作用,改变了瘤胃甲烷菌区系结构,降低了甲烷产量。

The study was to investigate the effect of different doses of 3-NOP added to high-concentration diets on methane production and methanogenic flora through in vitro ruminal fermentation.A completely randomized block design was used,including four groups:Control group(group C),low dose group(group LD),medium dose group(group MD)and high dose group(group HD),adding 0,0.4,0.8 and 1.2 mg 3-NOP to fermentation substrate,respectively.Fermentation culture in vitro was carried out for 24 h.The results showed that compared with control group,rumen methane production and methane production per gram of degradable substrate in each 3-NOP treatment group were significantly decreased(P<0.05),but hydrogen production and hydrogen production per gram of degradable substrate were significantly increased(P<0.05).The degradation rate of dry matter in rumen of HD group was significantly lower than that of other groups(P<0.05),and the total gas production per gram of degradable substrate was significantly higher than that of other groups(P<0.05).The Simspon index of ruminal fermentation in MD group was significantly lower than that in control group and LD group(P<0.05).The relative abundance of Methanosphaera in each 3-NOP treatment group was significantly lower than that in control group.The experiment indicates that 3-NOP changes the flora structure of rumen methanogens and reduces methane production through the specific inhibition of methyl-coenzyme M reductase.