Friedman Nir, Jami Elie, Mizrahi Itzhak
Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Department of Ruminant Science, Institute of Animal Sciences, Agricultural Research Organization, Volcani Center, Derech HaMaccabim 68, Rishon LeZion, Israel.
Environ Microbiol. 2017 Aug;19(8):3365-3373. doi: 10.1111/1462-2920.13846. Epub 2017 Aug 7.
Methanogenic archaea in the bovine rumen are responsible for the reduction of carbon molecules to methane, using various electron donors and driving the electron flow across the microbial food webs. Thus, methanogens play a key role in sustaining rumen metabolism and function. Research of rumen methanogenic archaea typically focuses on their composition and function in mature animals, while studies of early colonization and functional establishment remain scarce. Here, we investigated the metabolic potential and taxonomic composition of the methanogenic communities across different rumen developmental stages. We discovered that the methanogenesis process changes with age and that the early methanogenic community is characterized by a high activity of methylotrophic methanogenesis, likely performed by members of the order Methanosarcinales, exclusively found in young rumen. In contrast, higher hydrogenotrophic activity was observed in the mature rumen, where a higher proportion of exclusively hydrogenotrophic taxa are found. These findings suggest that environmental filtering acts on the archaeal communities and select for different methanogenic lineages during different growth stages, affecting the functionality of this ecosystem. This study provides a better understanding of the compositional and metabolic changes that occur in the rumen microbiome from its initial stages of colonization and throughout the animals' life.
牛瘤胃中的产甲烷古菌利用各种电子供体将碳分子还原为甲烷，并驱动电子在微生物食物网中流动。因此，产甲烷菌在维持瘤胃代谢和功能方面发挥着关键作用。瘤胃产甲烷古菌的研究通常集中在其在成年动物中的组成和功能，而早期定殖和功能建立的研究仍然很少。在这里，我们研究了不同瘤胃发育阶段产甲烷菌群的代谢潜力和分类组成。我们发现，产甲烷过程随年龄而变化，早期产甲烷群落的特征是甲基营养型产甲烷活性高，这可能是由甲烷八叠球菌目成员执行的，仅在幼龄瘤胃中发现。相比之下，在成熟瘤胃中观察到更高的氢营养活性，其中发现了更高比例的纯氢营养类群。这些发现表明，环境过滤作用于古菌群落，并在不同生长阶段选择不同的产甲烷谱系，影响这个生态系统的功能。这项研究有助于更好地理解瘤胃微生物群从最初定殖阶段到动物整个生命过程中发生的组成和代谢变化。
