McSweeney Christopher S, Halliday Michael, Mackie Roderick I
CSIRO Agriculture and Food, Queensland Biosciences Precinct, St Lucia, Brisbane, Queensland, Australia.
Zillmere, Brisbane, Queensland, Australia.
Appl Environ Microbiol. 2025 Aug 20;91(8):e0038025. doi: 10.1128/aem.00380-25. Epub 2025 Jul 17.
This paper examines several rumen bacteria in the Synergistota phylum, specifically focusing on their potential to detoxify harmful compounds found in plants grazed by ruminants. Synergistota bacteria ferment amino acids for energy, while rumen from which the phylum was named, can also metabolize toxins found in the forage plant (leucaena). Specifically, is able to detoxify mimosine, a non-protein amino acid in leucaena, by converting it into less harmful metabolites. Historically, was introduced to ruminants in Australia to mitigate leucaena toxicity based on the notion that the bacterium was absent on this continent. Recent studies indicate geographic variations in presence and effectiveness, suggesting that strain variability may impact its detoxification efficacy. PCR-based assays have improved the detection of , revealing its widespread distribution in Australia and globally, but often low abundance in ruminant microbiomes. Additionally, other rumen Synergistota species ( and ) have recently been isolated and identified as agents for metabolizing fluoroacetate, another toxin present in Australian flora. These bacteria degrade fluoroacetate through a novel molecular mechanism of reductive dehalogenation, thus producing fluoride ions and acetate as byproducts. This mechanism has been detected in soil and contaminated groundwater but not the rumen. These findings underscore the ecological importance of Synergistota bacteria in reducing plant toxicity in ruminants. Ongoing research is recommended to isolate new strains, optimize rumen populations of these bacteria, and further understand the molecular pathways involved in toxin degradation to enhance detoxification capabilities in ruminant populations.
本文研究了互养菌门中的几种瘤胃细菌，特别关注它们对反刍动物所食植物中发现的有害化合物进行解毒的潜力。互养菌门细菌通过发酵氨基酸获取能量，而该菌门得名的瘤胃，也能够代谢饲料植物（银合欢）中发现的毒素。具体而言，[具体细菌名称]能够通过将含羞草素（银合欢中的一种非蛋白质氨基酸）转化为危害较小的代谢物来对其进行解毒。历史上，[具体细菌名称]被引入澳大利亚的反刍动物体内，以减轻银合欢的毒性，其依据是该细菌在澳大利亚大陆不存在这一观念。最近的研究表明，[具体细菌名称]的存在和有效性存在地理差异，这表明菌株变异性可能会影响其解毒功效。基于聚合酶链反应的检测方法改进了对[具体细菌名称]的检测，揭示了其在澳大利亚和全球的广泛分布，但在反刍动物微生物群中的丰度通常较低。此外，最近还分离出了其他瘤胃互养菌物种（[具体细菌名称1]和[具体细菌名称2]），并确定它们是代谢氟乙酸盐（澳大利亚植物群中存在的另一种毒素）的媒介。这些细菌通过一种新的还原脱卤分子机制降解氟乙酸盐，从而产生氟离子和乙酸盐作为副产物。这种机制已在土壤和受污染的地下水中检测到，但在瘤胃中未检测到。这些发现强调了互养菌门细菌在降低反刍动物植物毒性方面的生态重要性。建议进行持续研究，以分离新菌株，优化这些细菌在瘤胃中的数量，并进一步了解毒素降解所涉及的分子途径，以提高反刍动物群体的解毒能力。
