Institute of Animal Science, University of Hohenheim, Stuttgart, Germany.
HoLMiR - Hohenheim Center for Livestock Microbiome Research, University of Hohenheim, Stuttgart, Germany.
Microbiol Spectr. 2024 Nov 5;12(11):e0394223. doi: 10.1128/spectrum.03942-23. Epub 2024 Sep 30.
The ruminant-microorganism symbiosis is unique by providing high-quality food from fibrous materials but also contributes to the production of one of the most potent greenhouse gases-methane. Mitigating methanogenesis in ruminants has been a focus of interest in the past decades. One of the promising strategies to combat methane production is the use of feed supplements, such as seaweeds, that might mitigate methanogenesis via microbiome modulation and direct chemical inhibition. We conducted investigations of the effect of three seaweeds (, , and ) harvested at different locations (Iceland, Scotland, and Portugal) on methane production. We applied metataxonomics (16S rRNA gene amplicons) and metagenomics (shotgun) methods to uncover the interplay between the microbiome's taxonomical and functional states, methanogenesis rates, and seaweed supplementations. Methane concentration was reduced by and , both harvested in Scotland and , with the greatest effect of the latter. acted through the reduction of archaea-to-bacteria ratios but not eukaryotes-to-bacteria. Moreover, application was accompanied by shifts in both taxonomic and functional profiles of the microbial communities, decreasing not only archaeal ratios but also abundances of methanogenesis-associated functions. "SGMT" ( or ; high methane yield) to "RO" ( and ; low methane yield) clades ratios were also decreased, indicating that application favored species that produce less methane. Most of the functions directly involved in methanogenesis were less abundant, while the abundances of the small subset of functions that participate in methane assimilation were increased.
The application of significantly reduced methane production . We showed that this reduction was linked to changes in microbial function profiles, the decline in the overall archaeal community counts, and shifts in ratios of "SGMT" and "RO" clades. and , obtained from Scotland, also decreased methane concentration in the total gas, while the same seaweed species from Iceland did not.
反刍动物-微生物共生体通过利用纤维材料提供高质量的食物而独具特色，但它也是最强大的温室气体之一——甲烷的主要产生源。过去几十年来，反刍动物甲烷生成的缓解一直是研究的重点。对抗甲烷生成的一种很有前途的策略是使用饲料补充剂，如海藻，通过微生物组调节和直接化学抑制来减轻甲烷生成。我们研究了在不同地点（冰岛、苏格兰和葡萄牙）收获的三种海藻（、、）对甲烷生成的影响。我们应用了宏基因组学（16S rRNA 基因扩增子）和宏基因组学（鸟枪法）方法，以揭示微生物组的分类和功能状态、甲烷生成率以及海藻补充剂之间的相互作用。在苏格兰和葡萄牙收获的 和 降低了甲烷浓度，其中效果最大的是 。 通过降低古菌与细菌的比例而不是真核生物与细菌的比例起作用。此外， 的应用伴随着微生物群落的分类和功能谱的变化，不仅降低了古菌的比例，还降低了与甲烷生成相关的功能的丰度。“SGMT”（或 ；高甲烷产量）到“RO”（和 ；低甲烷产量）枝系的比例也降低了，这表明 的应用有利于产生较少甲烷的 种。与甲烷生成直接相关的大多数功能的丰度降低，而参与甲烷同化的一小部分功能的丰度增加。
应用 显著降低了甲烷的生成量。我们表明，这种减少与微生物功能谱的变化、整个古菌群落计数的下降以及“SGMT”和“RO”枝系的比例的变化有关。在苏格兰获得的 和 也降低了总气体中的甲烷浓度，而来自冰岛的相同海藻种类则没有。
