Abstract：
Plastic pollution of the soil is a global issue of increasing concern, with far-reaching impact on the environment and human health. To fully understand the medium- and long-term impact of plastic dispersal in the environment, it is necessary to define its interaction with the residing microbial communities and the biochemical routes of its degradation and metabolization. However, despite recent attention on this problem, research has largely focussed on microbial functional potential, failing to clearly identify collective adaptation strategies of these communities. Our study combines genome-centric metagenomics and metatranscriptomics to characterise soil microbial communities adapting to high polyethylene and polyethylene terephthalate concentration. The microbiota were sampled from a landfill subject to decades-old plastic contamination and enriched through prolonged cultivation using these microplastics as the only carbon source. This approach aimed to select the microorganisms that best adapt to these specific substrates. As a result, we obtained simplified communities where multiple plastic metabolization pathways are widespread across abundant and rare microbial taxa. Major differences were found in terms of expression, which on average was higher in planktonic microbes than those firmly adhered to plastic, indicating complementary metabolic roles in potential microplastic assimilation. Moreover, metatranscriptomic patterns indicate a high transcriptional level of numerous genes in emerging taxa characterised by a marked accumulation of genomic variants, supporting the hypothesis that plastic metabolization requires an extensive rewiring in energy metabolism and thus provides a strong selective pressure. Altogether, our results provide an improved characterisation of the impact of microplastics derived from common plastics types on terrestrial microbial communities and suggest biotic responses investing contaminated sites as well as potential biotechnological targets for cooperative plastic upcycling.
摘要：
土壤的塑料污染是一个日益受到关注的全球性问题，对环境和人类健康有着深远的影响。为了充分了解塑料在环境中扩散的中长期影响，有必要定义其与居住微生物群落的相互作用以及其降解和代谢的生化途径。然而,尽管最近关注这个问题，研究主要集中在微生物功能潜力上，未能清楚地确定这些社区的集体适应战略。我们的研究结合了以基因组为中心的宏基因组学和超转录组学，以表征适应高聚乙烯和聚对苯二甲酸乙二醇酯浓度的土壤微生物群落。微生物群是从垃圾填埋场采样的，这些垃圾填埋场受到数十年的塑料污染，并通过使用这些微塑料作为唯一的碳源进行长期培养来富集。这种方法旨在选择最适合这些特定底物的微生物。因此,我们获得了简化的群落，其中多种塑料代谢途径广泛分布在丰富和稀有的微生物分类群中。在表达方面发现了主要差异，平均而言，浮游微生物的含量高于牢固地粘附在塑料上的微生物，表明在潜在的微塑料同化中的互补代谢作用。此外，metaranscriptomentpatternsindicateahightranscriptionlevelofnumbersofnumbersinemergingtaxacharacterizedbyamarkedaccumulationofgenemicvariants,支持以下假设：塑料代谢需要在能量代谢中进行广泛的重新布线，因此提供了强大的选择压力。总之,我们的研究结果提供了来自普通塑料类型的微塑料对陆地微生物群落的影响的改进表征，并提出了投资污染场所的生物反应以及合作塑料再循环的潜在生物技术目标。
