Assessing environmental gradients in relation to dark CO 2 fixation in estuarine wetland microbiomes

作者：Luise Grüterich, Jason Woodhouse, Peter Mueller, Amos Tiemann, Hans‐Joachim Ruscheweyh, Shinichi Sunagawa, Hans‐Peter Grossart, Wolfgang R. Streit · 发表于：Applied and Environmental Microbiology · 年份：2024 · DOI：10.1128/aem.02177-24 · 被引用次数：12 · 研究领域：Microbial Community Ecology and Physiology、Coastal wetland ecosystem dynamics、Methane Hydrates and Related Phenomena

ABSTRACT The rising atmospheric concentration of CO 2 is a major concern to society due to its global warming potential. In soils, CO 2 -fixing microorganisms are preventing some of the CO 2 from entering the atmosphere. Yet, the controls of dark CO 2 fixation are rarely studied in situ . Here, we examined the gene and transcript abundance of key genes involved in microbial CO 2 fixation along major environmental gradients within estuarine wetlands. A combined multi-omics approach incorporating metabarcoding, deep metagenomic, and metatranscriptomic analyses confirmed that wetland microbiota harbor four out of seven known CO 2 fixation pathways, namely, the Calvin cycle, reverse tricarboxylic acid cycle, Wood–Ljungdahl pathway, and reverse glycine pathway. These pathways are transcribed at high frequencies along several environmental gradients, albeit at different levels depending on the environmental niche. Notably, the transcription of the key genes for the reverse tricarboxylic acid cycle was associated with high nitrate concentration, while the transcription of key genes for the Wood–Ljungdahl pathway was favored by reducing, O 2 -poor conditions. The transcript abundance of the Calvin cycle was favored by niches high in organic matter. Taxonomic assignment of transcripts implied that dark CO 2 fixation was mainly linked to a few bacterial phyla, namely, Desulfobacterota , Methylomirabilota , Nitrospirota , Chloroflexota , and Pseudomonadota . IMPORTANCE The increasing co...