A metatranscriptomics‐based assessment of small‐scale mixing of sulfidic and oxic waters on redoxcline prokaryotic communities
A metatranscriptomics‐based assessment of small‐scale mixing of sulfidic and oxic waters on redoxcline prokaryotic communities
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基于宏转录组学的氧化还原素原核生物群落硫化水和含氧水小规模混合的评估
DOI：
10.1111/1462-2920.14499
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发表时间：
--
影响因子：
5.1
通讯作者：
K. Jürgens
中科院分区：
文献类型：
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作者：
P. L. Holtermann;D. Numberger;T. Schott;L. Umlauf;K. Jürgens
小规模混合引起的氧气横向侵入被认为塑造了海洋氧化还原跃层中的微生物活动。为了检验原核生物对这种混合事件的反应，我们在波罗的海中部进行了一次船上混合实验：直接或在混合后培养没有检测到氧化物质的含氧、含硝酸盐和硫化物的水样。虽然硝酸盐、亚硝酸盐和铵的浓度在所有培养过程中保持不变，但我们观察到在含有硫化物的培养物中，与氧气接触后硫化物的含量减少。在8.5h内的4个时间点跟踪了包括古细菌硝化菌以及伽马蛋白细菌和弯曲杆菌等自养生物的标志基因的转录。依赖于相同无机底物的伽马蛋白细菌和弯曲杆菌的转录图谱在时间上的对比表明，依赖于相同无机底物的伽马蛋白细菌和弯曲细菌的转录图谱存在差异。在厌氧硫化物样品中，依赖于氧化底物参与硝化、反硝化和硫氧化的特定古生菌和弯曲菌标记基因高度上调。我们认为，尽管硫化水中没有可测量的含氧化合物，但频繁的间歇性小规模入侵刺激了参与硝化、反硝化和硫氧化的基因永久上调。
Lateral intrusions of oxygen caused by small‐scale mixing are thought to shape microbial activity in marine redoxclines. To examine the response of prokaryotes to such mixing events we employed a shipboard mixing experiment in the euxinic central Baltic Sea: oxic, nitrate containing and sulfidic water samples without detectable oxygenized substances were incubated directly or after mixing. While nitrate, nitrite and ammonium concentrations stayed approximately constant in all incubations, we observed a decrease of sulfide after the contact with oxygen in the sulfide containing incubations. The transcription of marker genes from chemolithoauthotrophic key players including archaeal nitrifiers as well as gammaproteobacterial and campylobacterial autotrophic organisms that couple denitrification with sulfur‐oxidation were followed at four time points within 8.5 h. The temporally contrasting transcriptional profiles of gammaproteobacterial and campylobacterial denitrifiers that depend on the same inorganic substrates pointed to a niche separation. Particular archaeal and campylobacterial marker genes involved in nitrification, denitrification and sulfur oxidation, which depend on oxidized substrates, were highly upregulated in the anaerobic sulfidic samples. We suggest that, despite the absence of measurable oxygenated compounds in the sulfidic water, frequent intermittent small‐scale intrusions stimulate the permanent upregulation of genes involved in nitrification, denitrification and sulfur oxidation.