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.

中文翻译：

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元组学提供了关于碳氢化合物污染对微生物垫功能的影响的见解。

光合微生物垫是稳定的，自给自足的社区。由于其沿海地区的局限性，这些垫子经常暴露于碳氢化合物的污染之下并能够在其上生长。为了解释这种污染如何影响微生物垫的功能，我们比较了两个垫：一个受到慢性石油污染的污染垫和一个参考垫。使用宏基因组学和元转录组学方法确定了春季和秋季垫子的分类学和代谢结构。极高的污染扰乱了垫子的季节性变化。ABC转运蛋白，两组分系统和IV型分泌系统相关基因在被污染的垫子中过多。在两个垫子的基因组中，异源生物降解代谢均较小，并且只有被污染的垫子中参与多环芳烃降解的基因表达更高。有趣的是，在1年的研究期内，参与碳氢化合物活化的基因的表达率下降了，同时易降解的碳氢化合物也随之下降，这表明碳氢化合物污染具有短暂的影响。交链藻和海洋螺旋藻的破碳菌似乎是污染垫中碳氢化合物修复的关键。总体而言，被污染的微生物垫能够应对碳氢化合物的污染，并具有适应性功能，可以改变季节性行为。伴随着易降解碳氢化合物的减少，这提示了碳氢化合物污染的短暂影响。交链藻和海洋螺旋藻的破碳菌似乎是污染垫中碳氢化合物修复的关键。总体而言，被污染的微生物垫能够应对碳氢化合物的污染，并具有适应性功能，可以改变季节性行为。伴随着易降解碳氢化合物的减少，这提示了碳氢化合物污染的短暂影响。交链藻和海洋螺旋藻的破碳菌似乎是污染垫中碳氢化合物修复的关键。总体而言，被污染的微生物垫能够应对碳氢化合物的污染，并具有适应性功能，可以改变季节性行为。