Jones R J, Megarrity R G
Aust Vet J. 1986 Aug;63(8):259-62. doi: 10.1111/j.1751-0813.1986.tb02990.x.
Cattle and goats in Australia lack the ability to totally degrade 3-hydroxy-4(1H)-pyridone, also known as 3,4-dihydroxy pyridine (3,4 DHP), the ruminal metabolite of mimosine, a toxic aminoacid present in the leguminous shrub Leucaena leucocephala. Ruminants in Hawaii have this capacity due to the presence of micro-organisms able to rapidly degrade the DHP. A mixed bacterial population capable of rapidly degrading DHP in vitro was isolated from a goat on the island of Maui. Cultures were grown anaerobically, without added sugars, in Medium 98-5 containing DHP. Cultures at a dilution of 10(-12) from the original rumen fluid were introduced into Townsville and further sub-cultured and multiplied in vitro in strict isolation at the Oonoonba Veterinary Laboratory, Townsville. Infusion of the culture into a goat and a steer fed a 100% leucaena diet resulted in cessation of DHP excretion in the urine. After 60 days the serum thyroxine levels and thyroid size were normal and there were no clinical signs of disease. The ability of the rumen fluid to degrade DHP in vitro showed that the bacteria had become established in the rumen. In the absence of any disease in the animals, clearance has been given for the wider use of these cultures in areas where leucaena is grown. The limited evidence suggests that the leucaena toxicity problem can be solved by the use of these introduced bacteria.
澳大利亚的牛和山羊缺乏完全降解3-羟基-4(1H)-吡啶酮（也称为3,4-二羟基吡啶，即3,4-DHP）的能力，3,4-DHP是含羞草碱的瘤胃代谢产物，含羞草碱是豆科灌木银合欢中存在的一种有毒氨基酸。夏威夷的反刍动物具备这种能力，因为存在能够快速降解DHP的微生物。从毛伊岛的一只山羊身上分离出了一个能够在体外快速降解DHP的混合细菌群体。培养物在含有DHP的98-5培养基中厌氧培养，不添加糖。将来自原始瘤胃液稀释至10(-12)的培养物引入汤斯维尔，并在汤斯维尔的奥诺昂巴兽医实验室严格隔离下进一步进行体外传代培养和增殖。将培养物注入一只山羊和一头以100%银合欢为食的阉牛体内后，尿液中停止排出DHP。60天后，血清甲状腺素水平和甲状腺大小正常，且没有疾病的临床症状。瘤胃液在体外降解DHP的能力表明这些细菌已在瘤胃中定植。在动物没有任何疾病的情况下，已批准在种植银合欢的地区更广泛地使用这些培养物。有限的证据表明，通过使用这些引入的细菌可以解决银合欢毒性问题。
