Microplastic-Associated Biofilms and Their Role in the Fate of Microplastics in Aquatic Environment

Chemical pollutants from anthropogenic sources are frequently released into the aquatic environment. The accumulation and transfer of these chemicals is mediated by the assemblages of microbial communities that are attached to the substratum in the aquatic environment called biofilms. Biofilms are known to be involved not only in nutrient supply through sorption on their surfaces but also considered to be more prone to transfer hazardous chemicals in aquatic environment. Nowadays, biofilms and their interaction with microplastics (MPs) are a hot subject among the most concerning environmental issues. MPs being very tiny particles not only affect water bodies solely but also interact with aquatic living communities. MPs-associated biofilms are complex communities of microorganisms that coat and colonize the surfaces of MPs. The coating of biofilms on MPs can induce alterations in their chemical and physical properties. Moreover, they make MPs more buoyant and affect their degradation rate. The biofilm associated with MPs mediates MPs to degrade, which leads to more serious ecological concerns due to fragmentation of MPs into smaller particles. Biofilms enhance the aggregation, sedimentation, suspension, and transportation of MPs over long distances. Understanding the role of MPs-associated biofilms in the fate of MPs is very important for the assessment of their impacts on the environment and development of the mitigation practices. Further research investigations are needed to explore potential ecological complications induced by MPs-associated biofilms in the aquatic environment.