在海底下生物圈中,硫酸盐降解和发酵的细胞特异速率
Marion Jaussi1, Bo Barker Jørgensen1, Kasper U Kjeldsen1
1Department of Biology, Aarhus University, Aarhus, Denmark.
Frontiers in microbiology
|August 9, 2023
概括
深沉沉积物中的微生物生活依赖于古代有机物质. 能量流,电池数量和电力需求保持平衡,硫酸盐减硫剂在不同年龄段显示稳定,低能耗.
科学领域:
- 深层生物圈微生物学
- 地下生物地质化学 地下生物地质化学
- 微生物生态学 微生物生态学
背景情况:
- 地表微生物以古老的有机物质为生,其代谢活性较低.
- 深层生物圈的巨大体积使其在全球范围内具有重要意义,尽管活动较低.
- 埋藏的沉积物提供了一个稳定的环境来研究长期的微生物社区动态.
研究的目的:
- 研究深层地下沉积物中能量流,微生物群体规模和细胞功率需求之间的平衡.
- 在地质时间尺度上通过硫酸盐还原和发酵量化微生物能量消耗.
主要方法:
- 分析了10个沉积物核心,年龄从几年到数百万年.
- 通过硫酸盐还原和细胞计数来测量碳氧化率.
- 使用吉布斯自由能量计算功耗,并根据dsrB基因区分微生物群.
主要成果:
- 每个细胞的硫酸盐减少率与深度和年龄保持不变 (~10-2 fmol C 细胞-1 天),相当于每个细胞10-17 W.
- 减少硫酸盐的细胞表现出类似于增长最慢的无氧培养物的功耗消耗.
- 发酵细胞 (非dsrB) 获得剩余的能量,表现出随着沉积物年龄的增长而降低的代谢.
结论:
- 在能量流和微生物社区结构之间存在着稳定状态.
- 硫酸盐减少剂保持一致的低功耗要求,而发酵剂的活性随着沉积物年龄的增长而下降.
- 在较古老的沉积物中,深层微生物群落以发酵器为主,这是由于功率要求的显著差异造成的.
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