Environmental Microbiology, Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France.
Laboratoire de Microbiologie des Environnements Extrêmes, UMR6197, IFREMER, CNRS, Université de Bretagne Occidentale, Plouzané, France.
Microb Ecol. 2020 Aug;80(2):286-295. doi: 10.1007/s00248-020-01493-x. Epub 2020 Feb 19.
Photosynthetic microbial mats are stable, self-supported communities. Due to their coastal localization, these mats are frequently exposed to hydrocarbon contamination and are able to grow on it. To decipher how this contamination disturbs the functioning of microbial mats, we compared two mats: a contaminated mat exposed to chronic petroleum contamination and a reference mat. The taxonomic and metabolic structures of the mats in spring and fall were determined using metagenomic and metatranscriptomic approaches. Extremely high contamination disturbed the seasonal variations of the mat. ABC transporters, two-component systems, and type IV secretion system-related genes were overabundant in the contaminated mats. Xenobiotic degradation metabolism was minor in the metagenomes of both mats, and only the expression of genes involved in polycyclic aromatic hydrocarbon degradation was higher in the contaminated mat. Interestingly, the expression rates of genes involved in hydrocarbon activation decreased during the 1-year study period, concomitant with the decrease in easily degradable hydrocarbons, suggesting a transient effect of hydrocarbon contamination. Alteromonadales and Oceanospirillales hydrocarbonoclastic bacteria appeared to be key in hydrocarbon remediation in the contaminated mat. Overall, the contaminated microbial mat was able to cope with hydrocarbon contamination and displayed an adaptive functioning that modified seasonal behaviour.
光合微生物席是稳定的、自我支撑的群落。由于它们位于沿海地区，这些席经常受到碳氢化合物污染，并能够在其上生长。为了解释这种污染如何干扰微生物席的功能，我们比较了两个席：一个受到慢性石油污染的污染席和一个参考席。使用宏基因组学和宏转录组学方法确定了春季和秋季席的分类和代谢结构。极高的污染扰乱了席的季节性变化。在污染席中，ABC 转运蛋白、双组分系统和 IV 型分泌系统相关基因过度表达。两种席的宏基因组中，外来生物降解代谢都较少，只有参与多环芳烃降解的基因的表达在污染席中更高。有趣的是，参与烃类激活的基因的表达率在 1 年的研究期间下降，与易降解烃类的减少同时发生，表明烃类污染有短暂的影响。腐生单胞菌目和海洋螺旋菌目烃类降解细菌似乎是污染席中烃类修复的关键。总的来说，污染的微生物席能够应对碳氢化合物污染，并表现出适应功能，改变了季节性行为。
