Methanogen genomics to discover targets for methane mitigation technologies and options for alternative H2 utilisation in the rumen
Methanogen genomics to discover targets for methane mitigation technologies and options for alternative H2 utilisation in the rumen
复制标题
DOI：
10.1071/ea07203
复制
发表时间：
2008-01-01
影响因子：
--
通讯作者：
McSweeney, Christopher
中科院分区：
文献类型：
--
作者：
Attwood, Graeme;McSweeney, Christopher
减少反刍动物甲烷排放是确保以反刍动物为基础的农业可持续性的一个重要目标。甲烷在瘤胃中由产甲烷菌（产甲烷菌的一部分）形成，主要来自H-2和CO2。来自广泛栖息地的产甲烷菌正在进行基因组测序，以更好地了解其生物学，特别是确定肠道相关产甲烷菌抑制技术的目标。基因组比较正在确定共同的基因，而基因差异则提供了一个洞察适应，使产甲烷菌生存和持久性在不同的环境条件下。在瘤胃微生物食物网中，产甲烷菌执行去除H-2的有益任务，这允许还原的辅因子被再氧化和再循环，从而增强植物材料的分解和发酵。因此，瘤胃甲烷缓解策略需要考虑在甲烷生成缺乏（或水平降低）的情况下H-2利用的替代途径，以维持瘤胃功能。两种主要的替代方案是可能的：增强进行还原性产乙酸（将CO2和H-2结合形成乙酸）的瘤胃微生物或促进在代谢中间产物（苹果酸、富马酸和巴豆酸）转化为丙酸和丁酸期间消耗还原当量的生物体。更好地了解瘤胃中甲烷氧化的作用和规模也可能导致未来甲烷减排的选择。
Reducing ruminant methane emissions is an important objective for ensuring the sustainability of ruminant-based agriculture. Methane is formed in the rumen by methanogens (part of the domain Archaea), mainly from H-2 and CO2. Methanogens from a wide range of habitats are being genome-sequenced to gain a better understanding of their biology and, in particular, to identify targets for inhibition technologies for gut-associated methanogens. Genome comparisons are identifying common genes that de. ne a methanogen, while gene differences are providing an insight into adaptations that allow methanogen survival and persistence under different environmental conditions. Within the rumen microbial food web, methanogens perform the beneficial task of removing H-2, which allows reduced cofactors to be reoxidised and recycled, thereby enhancing the breakdown and fermentation of plant material. Therefore, rumen methane mitigation strategies need to consider alternative routes of H-2 utilisation in the absence (or decreased levels) of methanogenesis to maintain rumen function. Two main alternatives are possible: enhancing rumen microorganisms that carry out reductive acetogenesis (combining CO2 and H-2 to form acetate) or promotion of organisms that consume reducing equivalents during the conversion of metabolic intermediates (malate, fumarate and crotonate) into propionate and butyrate. A better understanding of the role and scale of methane oxidation in the rumen may also lead to future options for methane mitigation.