Bandini Francesca, Hchaichi Ilef, Zitouni Nesrin, Missawi Oumayma, Cocconcelli Pier Sandro, Puglisi Edoardo, Banni Mohamed
Dipartimento di Scienze e Tecnologie Alimentari per la sostenibilità della filiera agro-alimentare, Facoltà di Scienze Agrarie Alimentari ed Ambientali, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy.
Laboratory of Biochemistry and Environmental Toxicology, ISA Chott-Mariem, Sousse University, Sousse, Tunisia.
J Hazard Mater. 2021 Jun 5;411:125079. doi: 10.1016/j.jhazmat.2021.125079. Epub 2021 Jan 8.
Plastic wastes accumulation in marine environments is becoming a crucial issue; while the toxicity to biota is quite well explored, a gap of knowledge still exists on the role that plastics play in shaping bacterial community structures in marine conditions and their possible transmission to humans. The present study intended first to profile bacterial community structure in floating plastic particles (FP) biofilms and seawater from four Tunisian coastal areas using high-throughput sequencing (HTS) of 16S rDNA. Subsequently, mussels (Mytilus galloprovincialis) as filter feeding organisms were exposed to the FP to broaden the knowledge on the potential role played by environmental plastic particles in shaping bacterial community structures and on their possibility to act as vehicles of bacteria through the food web. The mussels' microbiota was microbiologically analyzed through HTS, and the Histidine Rich Glycoprotein (HRG) gene expression level was investigated as the main immune response. Our results clearly showed a great variation in the composition of bacterial communities of FP and seawater from different geographical areas. Moreover, the gills of mussels exposed to sterilized seawater and native FP from each site exhibited a wider bacterial biodiversity. The gene expression level of HRG was found to be significantly higher in animals exposed to native FP when compared to sterilized FP. Our results should be carefully considered in view of the Trojan horse effects of FP toward bacteria and its potential toxicity.
海洋环境中的塑料垃圾积累正成为一个关键问题；虽然对生物群的毒性已得到充分研究，但对于塑料在塑造海洋环境中细菌群落结构以及它们可能向人类传播方面所起的作用，仍存在知识空白。本研究首先旨在通过对16S rDNA进行高通量测序（HTS），分析来自突尼斯四个沿海地区的漂浮塑料颗粒（FP）生物膜和海水中的细菌群落结构。随后，将作为滤食性生物的贻贝（Mytilus galloprovincialis）暴露于FP中，以进一步了解环境塑料颗粒在塑造细菌群落结构方面的潜在作用，以及它们作为细菌通过食物网传播载体的可能性。通过HTS对贻贝的微生物群进行了微生物学分析，并研究了富含组氨酸糖蛋白（HRG）基因的表达水平作为主要免疫反应。我们的结果清楚地表明，来自不同地理区域的FP和海水中细菌群落的组成存在很大差异。此外，暴露于来自每个地点的灭菌海水和天然FP的贻贝鳃表现出更广泛的细菌生物多样性。与灭菌FP相比，发现暴露于天然FP的动物中HRG的基因表达水平显著更高。鉴于FP对细菌的特洛伊木马效应及其潜在毒性，我们的结果应予以谨慎考虑。
