Dependence of bacterial magnetosome morphology on chemical conditions in deep-sea sediments
Dependence of bacterial magnetosome morphology on chemical conditions in deep-sea sediments
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DOI：
10.1016/j.epsl.2019.02.015
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发表时间：
2016-12
影响因子：
5.3
通讯作者：
T. Yamazaki;Yohey Suzuki;M. Kouduka;N. Kawamura
中科院分区：
文献类型：
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作者：
T. Yamazaki;Yohey Suzuki;M. Kouduka;N. Kawamura
趋磁细菌（MTB）在铁的地球化学循环和沉积物的磁化恢复过程中起着重要作用。通常认为，产磁铁矿的山地车更喜欢缺氧-缺氧过渡区（OATZ）的化学条件。我们研究了分布的化石MTB磁铁矿（磁化石）和微生物的微生物与MTB在深海表层沉积物横跨OATZ。透射电子显微镜（TEM）观察和岩石磁性代用指标表明，磁化石通常发生在OATZ内和它上面，甚至在表面氧化层的顶部，和泪滴形态的磁化石的比例增加的OATZ内。从16 S rRNA基因片段的焦磷酸测序中获得了一致的结果。操作分类单位（OTU）相关的Nitrospirabine和OP 3 MTB，产生泪滴状磁小体，仅在OATZ内检测到，而OTU相关的α变形菌MTB，产生equant或细长的磁铁矿颗粒，分布在OATZ上方。这些结果表明，磁化石形态可以用来检测过去的OATZ，和一些MTB谱系可以普遍存在于海洋沉积物中，而不是局限于OATZ内。我们的研究结果表明，恢复磁化收购的时间可能取决于栖息MTB谱系。
Magnetotactic bacteria (MTB) play an important role in biogeochemical cycles of iron and remanent magnetization acquisition of sediments. It is generally considered that magnetite-producing MTB prefer chemical conditions in the oxic-anoxic transition zone (OATZ). We studied the distribution of fossil MTB magnetite (magnetofossils) and microbes phylogenetically related to MTB within deep-sea surface sediments across the OATZ. Transmission electron microscope (TEM) observations and rock-magnetic proxies show that magnetofossils commonly occur both within the OATZ and above it, even at the top of surface oxidized layers, and that the proportion of magnetofossils with a teardrop morphology increases within the OATZ. Consistent results were obtained from the pyrosequencing of 16S rRNA gene fragments. Operational taxonomic units (OTUs) related to Nitrospirae and OP3 MTB, which produce teardrop-shape magnetosomes, were detected only within the OATZ, whereas OTUs related to alphaproteobacterial MTB, which produce equant or elongated magnetite particles, were distributed above the OATZ. These results suggest that magnetofossil morphology can be used to detect past OATZs, and that some MTB lineages can occur ubiquitously in marine sediments rather than being limited within the OATZ. Our results imply that the timing of remanent magnetization acquisition may depend on the inhabiting MTB lineages.