School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3FX, U.K.
Materials and Chemical Engineering, School of Engineering, University of Aberdeen, Aberdeen AB24 3FX, U.K.
Environ Sci Technol. 2022 Feb 15;56(4):2300-2311. doi: 10.1021/acs.est.1c05106. Epub 2022 Feb 1.
Acute environmental perturbations are reported to induce deterministic microbial community assembly, while it is hypothesized that chronic perturbations promote development of alternative stable states. Such acute or chronic perturbations strongly impact on the pre-adaptation capacity to the perturbation. To determine the importance of the level of microbial pre-adaptation and the community assembly processes following acute or chronic perturbations in the context of hydrocarbon contamination, a model system of pristine and polluted (hydrocarbon-contaminated) sediments was incubated in the absence or presence (discrete or repeated) of hydrocarbon amendment. The community structure of the pristine sediments changed significantly following acute perturbation, with selection of different phylotypes not initially detectable. Conversely, historically polluted sediments maintained the initial community structure, and the historical legacy effect of chronic pollution likely facilitated community stability. An alternative stable state was also reached in the pristine sediments following chronic perturbation, further demonstrating the existence of a legacy effect. Finally, ecosystem functional resilience was demonstrated through occurrence of hydrocarbon degradation by different communities in the tested sites, but the legacy effect of perturbation also strongly influenced the biotic response. This study therefore demonstrates the importance of perturbation chronicity on microbial community assembly processes and reveals ecosystem functional resilience following environmental perturbation.
据报道，急性环境胁迫会导致确定性微生物群落组装，而慢性胁迫则被假设会促进替代稳定状态的发展。这种急性或慢性胁迫强烈影响对胁迫的预先适应能力。为了确定在烃污染背景下微生物预先适应水平和急性或慢性胁迫后群落组装过程的重要性，我们在不存在或存在（离散或重复）烃添加的情况下，用原始和污染（烃污染）沉积物的模型系统进行了孵育。在急性胁迫后，原始沉积物的群落结构发生了显著变化，最初无法检测到不同的类群的选择。相反，历史上受到污染的沉积物保持了初始的群落结构，而慢性污染的历史遗留效应可能促进了群落的稳定性。在慢性胁迫后，原始沉积物也达到了另一个稳定状态，进一步证明了遗留效应的存在。最后，通过在测试地点的不同群落中发生的烃降解，证明了生态系统功能的恢复力，但胁迫的遗留效应也强烈影响了生物响应。因此，这项研究证明了胁迫慢性对微生物群落组装过程的重要性，并揭示了环境胁迫后的生态系统功能恢复力。
