Microbial gene expression in anoxic subseafloor sediment was recently explored in the Baltic Sea and the Peru Margin. Our analysis of these data reveals diverse transcripts encoding proteins associated with neutralization of reactive oxygen species, including catalase, which may provide an in situ source of oxygen. We also detect transcripts associated with oxidation of iron and sulfur, and with reduction of arsenate, selenate and nitrate. Given limited input of electron acceptors from outside the system, these results suggest that the microbial communities use an unexpectedly diverse variety of electron acceptors. Products of water radiolysis and their interactions with sediment continuously provide diverse electron acceptors and hydrogen. Cryptic microbial utilization of these oxidized substrates and H₂ may be an important mechanism for multi-million-year survival under the extreme energy limitation in subseafloor sediment.

中文翻译：

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缺氧海底沉积物中的隐秘代谢

最近在波罗的海和秘鲁边缘探索了缺氧海底沉积物中的微生物基因表达。我们对这些数据的分析揭示了编码与活性氧中和相关的蛋白质的多种转录物，包括过氧化氢酶，它可能提供原位氧源。我们还检测与铁和硫的氧化以及砷酸盐、硒酸盐和硝酸盐的还原相关的转录物。鉴于来自系统外部的电子受体输入有限，这些结果表明微生物群落使用了出乎意料的多样化电子受体。水的辐射分解产物及其与沉积物的相互作用不断提供多种电子受体和氢。这些氧化底物和 H 的神秘微生物利用₂可能是海底沉积物极端能量限制下数百万年生存的重要机制。