Exaggerated Interaction between Biofilms-Developed Microplastics (Mps) as Vectors and Contaminants in Aquatic Environment

Abstract

Biofilms-developed microplastics (MPs) may serve as important vectors for contaminants in aquatic environment. Understanding the interaction of biofilms-developed MPs and coexisting contaminants is crucial to comprehending their vector capacity. However, little is known about how adverse effects of contaminants on colonized biofilms formation on MPs’ surface influence their vector capacity. This study investigated the interaction mechanism of biofilms colonized on surface of MPs with coexisting contaminants based on microcosm experiments with the help of biofilms characterization techniques such as SEM, CLSM, FTIR and XPS. The results indicate that the biomass of biofilms on polystyrene (PS) increase with over time, providing the additional plenty of oxygen-containing functional groups, and then promoting Cd accumulation by biofilms-developed PS. Meanwhile, coexisting Cd has the adverse effects, inducing more microorganisms to die and accelerating the senescence and shedding of biofilms colonized on MPs. As a result, the contaminants-vector capacity of biofilms-developed MPs could be mitigated. Thus, the adverse effects of coexisting contaminants to biofilms influences the capacity of MPs as vector in aquatic environment. Neglecting the negative effects of contaminants on biofilms may lead to an overestimation of the contaminants-vector capacity of biofilms-developed MPs. This study provides support for further accurate assessment of the interaction between biofilms-developed MPs as vectors and contaminants in aquatic environment.

Keywords: Biofilms, Microplastics (MPs), Vectors, Contaminants, Microcosmic system