Department of Functional and Evolutionary Ecology, University of Viennagrid.10420.37, Vienna, Austria.
Research Platform 'Plastics in the Environment and Society,' University of Viennagrid.10420.37, Vienna, Austria.
mSystems. 2022 Apr 26;7(2):e0141521. doi: 10.1128/msystems.01415-21. Epub 2022 Mar 1.
Polyethylene (PE) is one of the most abundant plastics in the ocean. The development of a biofilm on PE in the ocean has been reported, yet whether some of the biofilm-forming organisms can biodegrade this plastic in the environment remains unknown. Via metagenomics analysis, we taxonomically and functionally analyzed three biofilm communities using low-density polyethylene (LDPE) as their sole carbon source for 2 years. Several of the taxa that increased in relative abundance over time were closely related to known degraders of alkane and other hydrocarbons. Alkane degradation has been proposed to be involved in PE degradation, and most of the organisms increasing in relative abundance over time harbored genes encoding proteins essential in alkane degradation, such as the genes and CYP153, encoding an alkane monooxygenase and a cytochrome P450 alkane hydroxylase, respectively. Weight loss of PE sheets when incubated with these communities and chemical and electron microscopic analyses provided evidence for alteration of the PE surface over time. Taken together, these results provide evidence for the utilization of LDPE-associated compounds by the prokaryotic communities. This report identifies a group of genes potentially involved in the degradation of the LDPE polymeric structure and/or associated plastic additives in the ocean and describes a phylogenetically diverse community of plastic biofilm-dwelling microbes with the potential for utilizing LDPE-associated compounds as carbon and energy source. Low-density polyethylene (LDPE) is one of the most used plastics worldwide, and a large portion of it ends up in the ocean. Very little is known about its fate in the ocean and whether it can be biodegraded by microorganisms. By combining 2-year incubations with metagenomics, respiration measurements, and LDPE surface analysis, we identified bacteria and associated genes and metabolic pathways potentially involved in LDPE biodegradation. After 2 years of incubation, two of the microbial communities exhibited very similar taxonomic compositions mediating changes to the LDPE pieces they were incubated with. We provide evidence that there are plastic-biofilm dwelling bacteria in the ocean that might have the potential to degrade LDPE-associated compounds and that alkane degradation pathways might be involved.
聚乙烯（PE）是海洋中最丰富的塑料之一。已经有报道称，PE 上会形成生物膜，但其中一些生物膜形成的生物是否能在环境中生物降解这种塑料尚不清楚。通过宏基因组学分析，我们使用低密度聚乙烯（LDPE）作为唯一碳源对三个生物膜群落进行了分类学和功能分析，为期两年。随着时间的推移，相对丰度增加的一些分类群与已知烷烃和其他碳氢化合物降解菌密切相关。已经提出烷烃降解参与了 PE 的降解，而且随着时间的推移相对丰度增加的大多数生物都携带编码烷烃降解中必需蛋白的基因，例如基因和 CYP153，分别编码烷烃单加氧酶和细胞色素 P450 烷烃羟化酶。用这些群落孵育 PE 片时的重量损失以及化学和电子显微镜分析为随着时间的推移 PE 表面发生变化提供了证据。总之，这些结果为原核生物群落利用 LDPE 相关化合物提供了证据。本报告确定了一组可能参与 LDPE 聚合结构和/或海洋中相关塑料添加剂降解的基因，并描述了一个具有利用 LDPE 相关化合物作为碳和能源源潜力的具有多样塑料生物膜栖息微生物的群落。低密度聚乙烯（LDPE）是全球使用最广泛的塑料之一，其中很大一部分最终进入海洋。人们对它在海洋中的命运以及它是否可以被微生物生物降解知之甚少。通过将 2 年的孵育与宏基因组学、呼吸测量和 LDPE 表面分析相结合，我们确定了可能参与 LDPE 生物降解的细菌和相关基因和代谢途径。孵育 2 年后，两个微生物群落表现出非常相似的分类组成，介导了它们与所孵育的 LDPE 片的变化。我们提供的证据表明，海洋中存在具有潜在降解 LDPE 相关化合物能力的塑料生物膜栖息细菌，并且可能涉及烷烃降解途径。
