课题组张国晟同学于《Journal of Hazardous Materials》期刊上发表了题为《Conjugative antibiotic-resistant plasmids promote bacterial colonization of microplastics in water environments》的论文。
微塑料和抗生素抗性污染引起了世界范围的关注。当微塑料与携带抗生素抗性基因（ARGs）的抗生素耐药细菌（ARB）共存时，ARB会在微塑料表面定殖，形成独特的生物膜。生物膜中的ARB和ARGs密度更大，更难去除。然而，对影响微塑料-生物膜形成因素的研究还很有限。在本研究中，发现污水处理厂中出现过的质粒RP4能够促进细菌在微塑料上的不可逆定殖。假设其原因是接合菌毛的产生，接着选择潜在的接合菌毛合成促进剂“纳米氧化铝”和抑制剂“游离亚硝酸”（FNA）来验证这一假设。当RP4存在时，纳米氧化铝促进而FNA抑制细菌定殖。接合菌毛基因表达和ATP分析结果，证实了这一假设，即RP4对细菌在微塑料上定殖的影响机制主要与接合菌毛蛋白合成和细胞内ATP水平相关。本研究报道了质粒RP4、纳米氧化铝和FNA对微塑料-生物膜形成的影响，对其他研究者探索微塑料-生物膜具有一定的参考价值。
Abstract：Both microplastic and bacterial antibiotic resistance have attracted attention worldwide. When microplastics coexist with antibiotic-resistant bacteria (ARB), which carry antibiotic resistance genes (ARGs), ARB colonize the surface of microplastics, and a unique biofilm is formed. The ARB and ARGs in biofilms are denser and more difficult to remove. However, studies on the factors influencing the formation of microplastic biofilms are limited. In this study, plasmid RP4, which appeared in wastewater treatment plants, was found to be able to promote irreversible bacterial colonization of microplastics, and the hypothetical reason was conjugative pili expression. Then, the potential conjugative pili synthesis promoter “nanoalumina” and inhibitor “free nitrous acid” (FNA) were selected to test this hypothesis. Simultaneously, nanoalumina promoted and FNA inhibited bacterial colonization when RP4 existed. Combined with the gene expression and ATP analysis results, this hypothesis was confirmed, and the mechanism of RP4 on bacterial colonization was related mainly to conjugative pili protein synthesis and intracellular ATP. In this study, the effects of plasmid RP4, nanoalumina, and FNA on the formation of microplastic biofilms were reported, which has a certain reference value for other researchers exploring microplastic biofilms.
Key words: Microplastics; Conjugative plasmid; Bacterial colonization; ARB; Conjugative pili
【文章链接】https://www.sciencedirect.com/science/article/pii/S030438942200231X
