Exploring the role of biofilms in microplastic degradation dynamics

Abstract

Microplastic pollution is a growing menace to modern society. The alarming increase in the concentration of MPs throughout all ecosystems, mainly aquatic, has led to research on microplastic degradation through microorganisms. Microplastics in aqueous environments provide native microbes with a surface for attachment and transportation across ecosystems. Microplastics colonizing microbes are linked to major health threats such as the spread of antibiotic resistance genes, chemical contaminants, heavy metal pollutants, etc. with microplastics acting as a vector. Additionally, biofilm formation is often the first step towards enzymatic degradation of microplastics in natural ecosystems. Though multiple studies have documented the presence of microplastics in aqueous ecosystems, studies related to microplastic biofilm formation, and its effect on the substrate are still at a nascent stage. In this work, the ability of monocultures of native bacterial strains was tested for their ability to colonize and degrade LDPE. Furthermore, the potential of native microbial strains in river water to accumulate on and change the chemical properties of commercial LDPE and PET MPs was also tested through a microcosm experiment and FTIR spectra were generated for the biofilm-treated and PET microplastics to observe any change in the chemical nature. Results from the experiment revealed that the indigenous strain, PBYB was capable of surviving on LDPE microplastics as the sole source of carbon, indicating potential degradation of the plastic polymer.