Experimental Microbial Alteration and Fe Mobilization From Basaltic Rocks of the ICDP HSDP2 Drill Core, Hilo, Hawaii.
Experimental Microbial Alteration and Fe Mobilization From Basaltic Rocks of the ICDP HSDP2 Drill Core, Hilo, Hawaii.
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DOI：
10.3389/fmicb.2018.01252
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发表时间：
2018
影响因子：
5.2
通讯作者：
Behrens H
中科院分区：
文献类型：
--
作者：
Stranghoener M;Schippers A;Dultz S;Behrens H
为了更好地了解微生物活动在岩石蚀变和铁活化中的作用，通过批量实验室实验研究了单一细菌(伯克霍尔德氏菌)与ICDP HSDP2钻芯和合成玄武岩玻璃中玄武岩的相互作用。通过钻芯玄武岩样品的孵化实验，研究了生物蚀变和非生物蚀变过程中溶液化学的差异。此外，还进行了不同铁氧化还原状态和残余应力的合成玄武岩玻璃的定植实验，以评价它们对微生物活性和细胞表面附着的影响。在生物培养实验中，观察到了细菌的生长，只有当岩石样品的养分被耗尽时，钻芯玄武岩中的铁和其他常量元素才能释放到溶液中，超过非生物对照。在人工合成玄武岩玻璃的生物定植实验中，溶液中溶解的主要元素浓度随着残余应力和Fe(II)含量的增加而增加。此外，在生物定植实验中，溶解的铁和铝的浓度也有类似的增加，表明它们的溶解可能是由微生物的活动触发的。扫描电子显微镜的表面形貌图像显示，培养实验中玄武岩上的细胞在玻璃和高粗糙度表面上最丰富，在矿物上几乎没有细胞。在定植实验中，具有残余应力和高Fe(II)含量的玄武岩玻璃被紧密地覆盖在细胞生物膜上。相反，Fe(III)含量高、无残余应力的玻璃被稀疏地定植。因此，我们得出结论，结构结合铁最有可能被真菌假单胞菌用作营养物质。此外，我们假设，一旦环境中的养分枯竭，微生物的活动总体上会增加岩石的溶解。研究结果表明，玄武岩玻璃的微生物蚀变除受成分影响外，还受氧化还原状态和残余应力等因素的影响。
The interaction of a single bacterial species (Burkholderia fungorum) with basaltic rocks from the ICDP HSDP2 drill core and synthetic basaltic glasses was investigated in batch laboratory experiments to better understand the role of microbial activity on rock alteration and Fe mobilization. Incubation experiments were performed with drill core basaltic rock samples to investigate differences in the solution chemistry during biotic and abiotic alteration. Additionally, colonization experiments with synthetic basaltic glasses of different Fe redox states and residual stresses were performed to evaluate their influence on microbial activity and surface attachment of cells. In biotic incubation experiments bacterial growth was observed and the release of Fe and other major elements from drill core basaltic rocks to solution exceeded that of abiotic controls only when the rock sample assay was nutrient depleted. The concentration of dissolved major elements in solution in biotic colonization experiments with synthetic basaltic glasses increased with increasing residual stress and Fe(II) content. Furthermore, the concentration of dissolved Fe and Al increased similarly in biotic colonization experiments indicating that their dissolution might be triggered by microbial activity. Surface morphology imaging by SEM revealed that cells on basaltic rocks in incubation experiments were most abundant on the glass and surfaces with high roughness and almost absent on minerals. In colonization experiments, basaltic glasses with residual stress and high Fe(II) content were intensely covered with a cellular biofilm. In contrast, glasses with high Fe(III) content and no residual stress were sparsely colonized. We therefore conclude that structurally bound Fe is most probably used by B. fungorum as a nutrient. Furthermore, we assume that microbial activity overall increased rock dissolution as soon as the environment becomes nutrient depleted. Our results show that besides compositional effects, other factors such as redox state and residual stress can control microbial alteration of basaltic glasses.