Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, Barcelona, 08034, Catalunya, Spain.
Centre for Ecology and Evolution in Microbial Model Systems, EEMiS, Linnaeus University, Barlastgatan 11, 39182, Kalmar, Sweden.
Environ Microbiol. 2019 Apr;21(4):1466-1481. doi: 10.1111/1462-2920.14580. Epub 2019 Mar 21.
Thousands of semi-volatile hydrophobic organic pollutants (OPs) reach open oceans through atmospheric deposition, causing a chronic and ubiquitous pollution by anthropogenic dissolved organic carbon (ADOC). Hydrophobic ADOC accumulates in cellular lipids, inducing harmful effects on marine biota, and can be partially prone to microbial degradation. Unfortunately, their possible effects on microorganisms, key drivers of global biogeochemical cycles, remain unknown. We challenged coastal microbial communities from Ny-Ålesund (Arctic) and Livingston Island (Antarctica) with ADOC concentrations within the range of oceanic concentrations in 24 h. ADOC addition elicited clear transcriptional responses in multiple microbial heterotrophic metabolisms in ubiquitous groups such as Flavobacteriia, Gammaproteobacteria and SAR11. Importantly, a suite of cellular adaptations and detoxifying mechanisms, including remodelling of membrane lipids and transporters, was detected. ADOC exposure also changed the composition of microbial communities, through stimulation of rare biosphere taxa. Many of these taxa belong to recognized OPs degraders. This work shows that ADOC at environmentally relevant concentrations substantially influences marine microbial communities. Given that emissions of organic pollutants are growing during the Anthropocene, the results shown here suggest an increasing influence of ADOC on the structure of microbial communities and the biogeochemical cycles regulated by marine microbes.
数千种半挥发性疏水性有机污染物（OPs）通过大气沉积进入开阔海洋，导致人为溶解有机碳（ADOC）的慢性和普遍污染。疏水性 ADOC 积累在细胞脂质中，对海洋生物群产生有害影响，并且部分易于微生物降解。不幸的是，它们对微生物（全球生物地球化学循环的关键驱动因素）可能产生的影响仍然未知。我们用在海洋浓度范围内的 ADOC 浓度在 24 小时内挑战了来自 Ny-Ålesund（北极）和 Livingston 岛（南极洲）的沿海微生物群落。ADOC 的添加在丰度普遍的微生物异养代谢中引发了明显的转录反应，如黄杆菌、γ-变形菌和 SAR11。重要的是，检测到了一系列细胞适应和解毒机制，包括膜脂和转运蛋白的重塑。ADOC 暴露还通过刺激稀有生物圈分类群改变了微生物群落的组成。这些分类群中的许多属于公认的 OPs 降解菌。这项工作表明，在环境相关浓度下的 ADOC 会极大地影响海洋微生物群落。鉴于人为世期间有机污染物的排放正在增加，这里显示的结果表明 ADOC 对微生物群落结构和受海洋微生物调节的生物地球化学循环的影响越来越大。
