Activated carbon stimulates microbial diversity and PAH biodegradation under anaerobic conditions in oil-polluted sediments
Activated carbon stimulates microbial diversity and PAH biodegradation under anaerobic conditions in oil-polluted sediments
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DOI：
10.1016/j.chemosphere.2020.126023
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发表时间：
2020-06-01
期刊：
影响因子：
8.8
通讯作者：
Gunnarsson, Jonas S.
中科院分区：
文献类型：
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作者：
Bonaglia, Stefano;Broman, Elias;Gunnarsson, Jonas S.
微生物的生物降解是缓解自然界碳氢化合物污染的有效手段。微生物在好氧条件下比厌氧条件下更有效地降解，但大部分沉积物的体积通常是缺氧的。通过培养实验研究了萘（一种常见的多环芳烃（PAH））的生物降解潜力，以及在好氧/厌氧条件下存在/不存在活性炭（AC）时微生物群落的多样性。内源微生物的放射呼吸实验表明，在厌氧条件下，添加AC可促进萘的降解（96%）。然而，在好氧条件下，AC对萘的生物降解没有影响。在萘上培养微生物种群的生物增强试验表明，AC进一步促进了萘在缺氧条件下的降解（92%）。16S rRNA基因序列分析表明，AC对沉积物的修正增加了微生物群落多样性，改变了群落结构。在厌氧条件下，经AC处理后，Geobacter、Thiobacillus、sulphicurvum和产甲烷古细菌的相对丰度急剧增加。这些结果可能是由于AC颗粒促进了参与多环芳烃降解途径的微生物之间的直接种间电子转移（DIET）。我们认为微生物介导的重要生态系统功能（如碳氢化合物降解）可以被诱导，并且AC富集策略可以用于促进缺氧油污染沉积物和土壤的生物修复。(C) 2020作者。Elsevier Ltd.出版。
Biodegradation by microorganisms is a useful tool that helps alleviating hydrocarbon pollution in nature. Microbes are more efficient in degradation under aerobic than anaerobic conditions, but the majority of sediment by volume is generally anoxic. Incubation experiments were conducted to study the biodegradation potential of naphthalene-a common polycyclic aromatic hydrocarbon (PAH)-and the diversity of microbial communities in presence/absence of activated carbon (AC) under aerobic/anaerobic conditions. Radio-respirometry experiments with endogenous microorganisms indicated that degradation of naphthalene was strongly stimulated (96%) by the AC addition under anaerobic conditions. In aerobic conditions, however, AC had no effects on naphthalene biodegradation. Bioaugmentation tests with cultured microbial populations grown on naphthalene showed that AC further stimulated (92%) naphthalene degradation in anoxia. Analysis of the 16S rRNA gene sequences implied that sediment amendment with AC increased microbial community diversity and changed community structure. Moreover, the relative abundance of Geobacter, Thiobacillus, Sulfuricurvum, and methanogenic archaea increased sharply after amendment with AC under anaerobic conditions. These results may be explained by the fact that AC particles promoted direct interspecies electron transfer (DIET) between microorganisms involved in PAH degradation pathways. We suggest that important ecosystem functions mediated by microbes-such as hydrocarbon degradation-can be induced and that AC enrichment strategies can be exploited for facilitating bioremediation of anoxic oil-contaminated sediments and soils. (C) 2020 The Authors. Published by Elsevier Ltd.