Witzig M, Zeder M, Rodehutscord M
Universität Hohenheim, Institut für Nutztierwissenschaften, 70593 Stuttgart, Germany.
Technobiology GmbH, 6033 Buchrain, Switzerland.
Anaerobe. 2018 Apr;50:44-54. doi: 10.1016/j.anaerobe.2018.01.012. Epub 2018 Jan 31.
This study examined whether the methane-decreasing effect of monensin (∼21%) and different hydrolysable tannins (24%-65%) during in vitro fermentation of grass silage was accompanied by changes in abundances of cellulolytics and methanogens. Samples of liquid (LAM) and solid (SAM) associated microbes were obtained from two rumen simulation technique experiments in which grass silage was either tested in combination with monensin (0, 2 or 4 mg d) or with different tannin extracts from chestnut, valonea, sumac and grape seed (0 or 1.5 g d). Total prokaryotes were quantified by 4',6-diamidino-2-phenylindol (DAPI) staining of paraformaldehyde-ethanol-fixed cells and relative abundances of ruminal cellulolytic and methanogenic species were assessed by real time quantitative PCR. Results revealed no change in absolute numbers of prokaryotic cells with monensin treatment, neither in LAM nor in SAM. By contrast, supplementation of chestnut and grape seed tannins decreased total prokaryotic counts compared to control. However, relative abundances of total methanogens did not differ between tannin treatments. Thus, the decreased methane production by 65% and 24% observed for chestnut and grape seed tannins, respectively, may have been caused by a lower total number of methanogens, but methane production seemed to be also dependent on changes in the microbial community composition. While the relative abundance of F. succinogenes decreased with monensin addition, chestnut and valonea tannins inhibited R. albus. Moreover, a decline in relative abundances of Methanobrevibacter sp., especially M. ruminantium, and Methanosphaera stadtmanae was shown with supplementation of monensin or chestnut tannins. Proportions of Methanomicrobium mobile were decreased by monensin in LAM while chestnut and valonea had an increasing effect on this methanogenic species. Our results demonstrate a different impact of monensin and tannins on ruminal cellulolytics and gave indication that methane decrease by monensin and chestnut tannins was associated with decreased abundances of M. ruminantium and M. stadtmanae.
本研究考察了莫能菌素（约21%）和不同水解单宁（24%-65%）在青贮草体外发酵过程中降低甲烷的效果是否伴随着纤维素分解菌和产甲烷菌丰度的变化。从两个瘤胃模拟技术实验中获取了与液体（LAM）和固体（SAM）相关的微生物样本，在这两个实验中，青贮草分别与莫能菌素（0、2或4 mg/d）或与来自栗木、橡椀、漆树和葡萄籽的不同单宁提取物（0或1.5 g/d）组合进行测试。通过对多聚甲醛 - 乙醇固定细胞进行4',6 - 二脒基 - 2 - 苯基吲哚（DAPI）染色对总原核生物进行定量，并通过实时定量PCR评估瘤胃纤维素分解菌和产甲烷菌物种的相对丰度。结果显示，莫能菌素处理后，LAM和SAM中，原核细胞的绝对数量均未发生变化。相比之下，与对照相比，添加栗木和葡萄籽单宁降低了总原核生物数量。然而，单宁处理之间总产甲烷菌的相对丰度没有差异。因此，分别观察到栗木和葡萄籽单宁使甲烷产量降低了65%和24%，这可能是由于产甲烷菌总数减少所致，但甲烷产量似乎也取决于微生物群落组成的变化。添加莫能菌素后，琥珀酸丝状杆菌的相对丰度降低，而栗木和橡椀单宁抑制了白色瘤胃球菌。此外，添加莫能菌素或栗木单宁后，短双歧杆菌属，尤其是反刍短双歧杆菌和史氏甲烷短杆菌的相对丰度下降。莫能菌素使LAM中活动甲烷微菌的比例降低，而栗木和橡椀对该产甲烷菌物种有增加作用。我们的结果表明莫能菌素和单宁对瘤胃纤维素分解菌有不同影响，并表明莫能菌素和栗木单宁使甲烷减少与反刍短双歧杆菌和史氏甲烷短杆菌丰度降低有关。
