塑料垃圾是最常见的海洋垃圾，导致日益严重的全球污染问题，据报道，每年大约有480-1270万吨塑料碎片进入海洋。由于塑料的持久性有害性。据估计，每年有100万只鸟类和1万只海洋动物因摄入塑料或被困在海洋塑料中而死亡，同时其破碎成的微塑料容易在食物链中积累和摄入到达顶级捕食者。填埋、焚烧、回收和生物降解处理塑料垃圾是最主要的几种途径。

Plastic waste is the most common form of waste in the sea, leading to a growing global pollution problem with approximately 4.8 to 12.7 million tons of plastic waste reportedly entering the ocean each year. Due to the persistent harmful nature of plastics, an estimated 1 million birds and 10,000 marine animals die each year from ingesting plastics or becoming trapped in plastics in the sea, while the fragmentation into microplastics tends to accumulate in the food chain and reach top predators in the end. Landfills, incineration, recycling and biodegradable disposal of plastic waste are some of the most prominent pathways.

2021年8月15日，来自中国科学院海洋研究所的研究人员在《Journal of Hazardous Materials》上发表了一篇名为“A marine bacterial community capable of degrading poly(ethylene terephthalate) and polyethylene”的研究论文，文章的中文译文为《一种能降解聚对苯二甲酸乙酯和聚乙烯的海洋细菌群落》。

On August 15, 2021, researchers from the Institute of Oceanography (Chinese Academy of Sciences) published a paper in Journal of Hazardous Materials titled “A marine bacterial community capable of degrading poly(ethylene terephthalate) and biodegradable plastic waste” whose Chinese name was “一种能降解聚对苯二甲酸乙酯和聚乙烯的海洋细菌群落”.

文章中使用了一种大规模筛选的方法，从海湾不同地点采集了约300个塑料碎片污染的海洋沉积物样本，筛选了能够使用含有PET的塑料饮料瓶或商用PE袋作为主要碳源的微生物，发现了一个独特的海洋细菌群落（名CAS6），能够有效定植和降解聚对苯二甲酸乙酯(PET)和聚乙烯(PE)。采用16S rRNA定量测序和培养方法，获得了3株介导塑料降解的细菌。采用多种技术来表征菌群对PET和PE的有效降解，同时通过转录组学的方法来研究其塑料降解过程和重建的细菌群落潜在的降解机制。

The research team used a screening approach on hundreds of plastic waste-associated samples and discovered a marine bacterial community capable of efficiently colonizing and degrading both poly (ethylene terephthalate) (PET) and polyethylene (PE). Using absolute quantitative 16S rRNA sequencing and cultivation methods, the research team obtained corresponding abundance and purified cultures of three bacterial strains that mediated plastic degradation. The research team further performed numerous techniques to characterize the efficient degradation of PET and PE by the reconstituted bacterial community containing these three bacteria. Additionally, the research team we used liquid chromatography-mass spectrometry to further demonstrate the degradation of PET and PE films by the reconstituted bacterial community. The research team conducted transcriptomic methods to investigate the plastic degradation process and potential degradation mechanisms mediated by our reconstituted bacterial community.

作者在研究中对比了单个细菌与CAS6菌落的区别，CAS6菌群比任何单一菌群有更大的塑料降解功能。同时排除了塑料添加剂薄膜的影响，相比于降解PET，CAS6联盟降解PE更加高效。

In the study, the authors compared individual bacteria with CAS6 colonies which had a greater plastic degradation than any single colony. Also excluding the effect of plastic additive films, the CAS6 consortium degraded PE more efficiently compared to degrading PET.

为了探究重组菌群介导的塑料降解过程及其可能的机制，研究在PET或PE膜存在下对该菌群进行了转录组分析。发现在三种细菌(Exiguobacterium sp.，Halomonas sp.，Ochrobactrum sp.)中，与能量生产和细胞生长相关的基因，包括柠檬酸循环和核糖体生物合成基因，都显著上调，其中上调最显著的基因与生物被膜形成(如群体感应、细菌趋化、鞭毛组装和双组分系统)、细菌分泌系统和细胞生长/繁殖(如柠檬酸循环、碳代谢、脂肪酸降解和核糖体生物合成)密切相关。

To explore the plastic degradation process and potential mechanisms mediated by our reconstituted bacterial community, the research team performed a macro transcriptome analysis of this flora in the presence of PET or PE film. The research team found genes associated with energy production and cell growth, including citrate cycle and ribosomal biosynthesis genes, to be significantly upregulated in all three bacterial species (Exiguobacterium sp., Halomonas sp., Ochrobactrum sp.). The most markedly up-regulated genes were closely related to biofilm formation (such as quorum sensing, bacterial chemotaxis, flagellar assembling and two-component system), bacterial secretion system, and cell growth/reproduction (such as citrate cycle, carbon metabolism, fatty acid degradation and ribosomal biosynthesis), regardless of the plastic type and incubation time.

总之，文章中的研究为未来从海洋环境中获得塑料降解剂提供了一个强有力的候选生物群落和思路。

In conclusion, the study provides a strong candidate bacterial community and idea for future plastic degraders from the marine environment.

来源：https://sci-hub.st/10.1016/J.JHAZMAT.2021.125928