Conventional plastics and bioplastics are known to accumulate in aquatic ecosystems, emerging as new surfaces for biofilm formation and gene exchanges. On the other hand, the fate of non-conventional bioplastics in the marine environment is still unclear. In this study we have measured, by means of crystal violet test and scanning electron microscopy (SEM), the ability of two model bacteria, Vibrio harveyi and Enterococcus faecalis, to form biofilms on low-density polyethylene (PE), polylactic acid (PLA) and starch-based bioplastic (SBB) surfaces. Experiments were conducted in artificial sea water, incubating squares of 3 cm² of the three plastics with the two model microorganisms and sampling overnight, and at 3 and 6 days. The presence of biofilms on plastic surfaces was detected from day one of incubation and SBB was the material with the highest biofilm formation. E. faecalis formed the thickest biofilm after 3 days with PLA and SBB, but did not remain stable, and after 6 days with PE. The maximum biofilm formation of V. harveyi was obtained overnight with SBB and PE, and after 3 days with PLA. Our data indicate that both plastic and bioplastics support the formation of biofilms of model pathogenic bacteria, highlighting potential concerns for human health.

中文翻译：

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粪肠球菌和哈维弧菌在海洋条件下使低密度聚乙烯和可生物降解的塑料成为可能。

已知传统的塑料和生物塑料会在水生生态系统中积累，并逐渐成为生物膜形成和基因交换的新表面。另一方面，海洋环境中非常规生物塑料的命运仍不清楚。在这项研究中，我们通过结晶紫测试和扫描电子显微镜（SEM）测量了两种模式细菌哈维弧菌和粪肠球菌在低密度聚乙烯（PE）和聚乳酸（PLA）上形成生物膜的能力。）和淀粉基生物塑料（SBB）表面。在人工海水中进行实验，孵化面积为3 cm ²用三种模型微生物对三种塑料进行分析，并分别在3天和6天取样过夜。从培养的第一天起就检测到塑料表面上存在生物膜，而SBB是生物膜形成最高的材料。用PLA和SBB处理3天后，粪肠球菌形成了最厚的生物膜，但使用PE处理6天后，粪肠球菌却没有保持稳定。用SBB和PE过夜获得哈维弧菌最大的生物膜形成，而使用PLA则获得3天后最大的生物膜形成。我们的数据表明，塑料和生物塑料都支持模型病原菌生物膜的形成，突出了对人类健康的潜在关注。