Department of Animal Sciences, The Ohio State University, 2029 Fyffe Road, Columbus, OH, 43210, USA.
Appl Microbiol Biotechnol. 2014 Jan;98(2):897-905. doi: 10.1007/s00253-013-4930-x. Epub 2013 Apr 30.
This study investigated the effects of vanillin on methanogenesis and rumen fermentation, and the responses of ruminal protein-degrading bacteria to vanillin (at concentrations of 0, 0.76 and 1.52 g/L), essential oils (clove oil, 1 g/L; origanum oil, 0.50 g/L, and peppermint oil, 1 g/L), and quillaja saponin (at concentration of 0 and 6 g/L) in vitro. Methane production, degradabilities of feed substrate, and ammonia concentration decreased linearly with increasing doses of vanillin. Concentration of total volatile fatty acids also decreased, whereas proportion of butyrate tended to increase linearly with increasing doses of vanillin. Protozoa population decreased, but abundances of Ruminococcus flavefaciens, Prevotella bryantii, Butyrivibrio fibrisolvens, Prevotella ruminicola, Clostridium aminophilum, and Ruminobacter amylophilus increased with increasing doses of vanillin. Origanum and clove oils resulted in lower ammonia concentrations compared to control and peppermint oil. All the tested essential oils decreased abundances of protozoa, Selenomonas ruminantium, R. amylophilus, P. ruminicola and P. bryantii, with the largest decrease resulted from origanum oil followed by clove oil and peppermint oil. The abundances of Megasphaera elsdenii, C. aminophilum, and Clostridium sticklandii were deceased by origanum oil while that of B. fibrisolvens was lowered by both origanum and clove oils. Saponin decreased ammonia concentration and protozoal population, but increased the abundances of S. ruminantium, R. amylophilus, P. ruminicola, and P. bryantii, though the magnitude was small (less than one log unit). The results suggest that reduction of ammonia production by vanillin and saponin may not be caused by direct inhibition of major known proteolytic bacteria, and essential oils can have different inhibitory effects on different proteolytic bacteria, resulting in varying reduction in ammonia production.
本研究探讨了香草醛对甲烷生成和瘤胃发酵的影响，以及瘤胃蛋白降解菌对香草醛（浓度分别为 0、0.76 和 1.52 g/L）、精油（丁香油 1 g/L、牛至油 0.50 g/L 和薄荷油 1 g/L）和奎那酸皂甙（浓度分别为 0 和 6 g/L）的体外反应。随着香草醛剂量的增加，甲烷产量、饲料底物的降解率和氨浓度呈线性下降。总挥发性脂肪酸的浓度也降低，而丁酸的比例则呈线性增加。随着香草醛剂量的增加，原生动物的数量减少，但瘤胃球菌属、普雷沃氏菌属、丁酸纤维菌属、普雷沃氏菌属、梭菌属和瘤胃杆菌属的丰度增加。与对照组和薄荷油相比，牛至油和丁香油导致氨浓度降低。所有测试的精油都降低了原生动物、琥珀酸弧菌、瘤胃杆菌、普雷沃氏菌、丁酸纤维菌、普雷沃氏菌和瘤胃杆菌的丰度，其中牛至油的降幅最大，其次是丁香油和薄荷油。巨球形菌属、梭菌属和 stickland 氏梭菌的丰度被牛至油降低，而丁酸纤维菌的丰度被牛至油和丁香油降低。皂甙降低了氨浓度和原生动物数量，但增加了琥珀酸弧菌、瘤胃杆菌、普雷沃氏菌和普雷沃氏菌的丰度，尽管幅度较小（小于一个对数单位）。结果表明，香草醛和皂甙降低氨产量可能不是由于直接抑制主要已知的蛋白水解菌引起的，精油对不同的蛋白水解菌有不同的抑制作用，导致氨产量的降低程度不同。
