Soil aggregates by design: Manufactured aggregates with defined microbial composition for interrogating microbial activities in soil microhabitats
Soil aggregates by design: Manufactured aggregates with defined microbial composition for interrogating microbial activities in soil microhabitats
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DOI：
10.1016/j.soilbio.2020.107870
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发表时间：
2020-09-01
影响因子：
9.7
通讯作者：
Avery, Simon, V
中科院分区：
文献类型：
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作者：
Harvey, Harry J.;Wildman, Ricky D.;Avery, Simon, V
据报道，土壤团聚体内部和外部之间存在微生物群落结构的差异，但土壤团聚体对土壤中微生物活性的影响，对土壤健康至关重要，已证明难以以受控的方式进行研究。我们已经开发出一种新的方法，在实验室中制造土壤大团聚体的能力，引入选择的微生物的endo或exo-aggregate环境，为实验研究提供了新的途径。X射线计算机断层扫描成像证实，制造的聚集体具有与天然形成的聚集体相似的总体孔隙率、孔径和孔连通性。我们利用这种新的方法来测试的假设，即微生物聚集体内的保护免受环境压力，相比，位于聚集体表面附近的生物体。引入到制造的土壤团聚体的内部或外部的酵母菌的土壤分离株在金属或缺氧应力的生存没有显着差异，但团聚体内的生物体受到保护，免受热应力在一个时间依赖性的方式。结果表明，微生物群落可能会受到保护，从聚集的土壤结构所产生的复杂的多孔结构，特别是环境扰动，并强调这种新的方法，提高我们的理解的土壤物理环境和相关的土壤生物之间的相互作用的价值。
Differences in the structure of microbial communities are reported to exist between the inside and outside of soil aggregates, but the impacts of soil aggregation on microbial activity in soils, essential for soil health, have proven difficult to study in a controlled manner. We have developed a new method to manufacture soil macroaggregates in the laboratory with the ability to introduce microorganisms of choice to the endo- or exo-aggregate environments, offering new avenues for experimental research. X-ray Computed Tomography imaging confirmed the manufactured aggregates had similar overall porosity, pore size and pore connectivity to naturally-formed aggregates. We exploited this new approach to test the hypothesis that microorganisms within aggregates are protected from environmental stresses, in comparison to organisms located near aggregate surfaces. Soil isolates of yeasts introduced to the interior or exterior of manufactured soil aggregates showed no significant difference in the survival of metal- or anoxic-stresses, but organisms within aggregates were protected from heat stress in a time-dependent manner. The results indicate that microbial communities may be protected from particular environmental perturbations by the complex porous architecture that arises from the aggregated soil structure, and underscore the value of this new approach for improving our understanding of the interactions between the soil physical environment and the associated soil biology.