Helmbrecht Vanessa, Reichelt Robert, Grohmann Dina, Orsi William D
Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, Germany.
Institute of Biochemistry, Genetics and Microbiology, Institute of Microbiology and Archaea Centre, Single-Molecule Biochemistry Lab and Regensburg Center for Biochemistry, University of Regensburg, Regensburg, Germany.
Nat Ecol Evol. 2025 May;9(5):769-778. doi: 10.1038/s41559-025-02676-w. Epub 2025 Apr 30.
Molecular hydrogen is the electron donor for the ancient exergonic reductive acetyl-coenzyme A pathway (acetyl-CoA pathway), which is used by hydrogenotrophic methanogenic archaea. How the presence of iron-sulfides influenced the acetyl-CoA pathway under primordial early Earth geochemistry is still poorly understood. Here we show that the iron-sulfides mackinawite (FeS) and greigite (FeS), which formed in chemical garden experiments simulating geochemical conditions of the early Archaean eon (4.0-3.6 billion years ago), produce abiotic H in sufficient quantities to support hydrogenotrophic growth of the hyperthermophilic methanogen Methanocaldococcus jannaschii. Abiotic H from iron-sulfide formation promoted CO fixation and methanogenesis and induced overexpression of genes encoding the acetyl-CoA pathway. We demonstrate that H from iron-sulfide precipitation under simulated early Earth hydrothermal geochemistry fuels a H-dependent primordial metabolism.
分子氢是古生代放能还原性乙酰辅酶A途径（乙酰辅酶A途径）的电子供体，氢营养型产甲烷古菌会利用该途径。在早期地球原始地球化学条件下，硫化铁的存在如何影响乙酰辅酶A途径，目前仍知之甚少。在这里，我们表明，在模拟太古宙早期（40亿至36亿年前）地球化学条件的化学花园实验中形成的硫化铁——马基诺矿（FeS）和硫复铁矿（FeS），能产生足够数量的非生物氢，以支持嗜热产甲烷菌詹氏甲烷球菌的氢营养生长。硫化铁形成过程中产生的非生物氢促进了CO固定和甲烷生成，并诱导了编码乙酰辅酶A途径的基因的过表达。我们证明，在模拟早期地球热液地球化学条件下，硫化铁沉淀产生的氢为依赖氢的原始代谢提供了能量。
