Textile waste and microplastic induce activity and development of unique hydrocarbon-degrading marine bacterial communities

Knowledge of biofilm formation on pollutants in the marine realm is expanding, but how communities respond to substrates during colonization remains poorly understood. Here, we assess community assembly in response to three different micropollutants, virgin high-density polyethylene (HDPE) microbeads, polysorbate-20 (Tween), and textile fibers. Raman characterization, high-throughput DNA sequencing data, and respiration measurements reveal a stimulation of activity in the presence of micropollutants, and how this is translated into selection for significantly different communities colonizing the different substrates. Furthermore, respiration rates were higher in the presence of light, resulting in significantly different communities compared to dark incubations. Bacterial taxa, closely related to the well-known hydrocarbonoclastic bacteria Kordiimonas spp. and Alcanivorax spp., were enriched in the presence of textile-waste and virgin HDPE. The findings demonstrate an increased metabolic response by marine hydrocarbon-degrading bacterial taxa in the presence of microplastics and textile waste, highlighting their biodegradation potential. The metabolic stimulation in the presence of light can be partly explained by photochemical dissolution of the textile waste and plastic into smaller bioavailable compounds. Our results suggest that the development and increased activity of these unique microbial communities may potentially play a role in the bioremediation of the relatively long-lived textile and microplastic pollutants in marine habitats.

目前学界对海洋环境中污染物表面生物膜形成机制的认知正逐步深化，但微生物群落在定殖过程中如何响应不同基底的问题仍有待系统解析。本研究针对三种不同微污染物——原生高密度聚乙烯（high-density polyethylene, HDPE）微珠、聚山梨酯-20（Tween）及纺织纤维——开展群落组装响应评估。研究通过拉曼表征、高通量DNA测序数据与呼吸速率测量，揭示了微污染物存在下微生物活性的激活效应，以及该活性如何驱动对不同基底定殖群落的显著筛选作用。此外，光照培养条件下的呼吸速率显著高于暗培养，由此形成的群落结构与暗培养组存在显著差异。与经典解烃细菌Kordiimonas spp.和Alcanivorax spp.亲缘关系密切的细菌类群，在纺织废弃物与原生HDPE存在的环境中显著富集。本研究结果证实，海洋解烃细菌类群在微塑料与纺织废弃物存在时代谢响应显著增强，凸显了其生物降解潜力。光照下的代谢激活现象，可部分归因于纺织废弃物与塑料经光化学溶解后生成了更多小分子生物可利用化合物。研究结果表明，这类独特微生物群落的形成与活性提升，或可在海洋生境中持久性纺织污染物与微塑料污染物的生物修复进程中发挥潜在作用。