Impacts of Biofilm Formation on the Physicochemical Properties and Toxicity of Microplastics: A Concise Review

Abstract

Microplastics (MPs) are of global concern due to their slow degradation in the environment and the potential of inducing adverse effects on organisms. In aquatic ecosystems, microbes routinely colonize MPs and develop biofilms on their surfaces. Biofilms are assemblages of surface-associated microbial cells that are enclosed in an extracellular polymeric substance. Emerging evidence has suggested that the development of biofilm can alter the physicochemical properties and the pollutant adsorption capability on MPs. In this article, we review the impacts of biofilm formation on MP properties, ecotoxicity, and fate. First, we summarize the environmental factors that modulate biofilm formation, as well as the unique components of biofilm on MP. Next, we review current understanding on the influence of biofilm formation on the physical and chemical properties of MPs and discuss how these changes affect their pollutant adsorption capacity. Finally, we discuss how biofilm formation on MPs affects their ingestion by organisms and nutrient cycling in aquatic environments. Graphical Abstract

Enhancing Biogas Production Amidst Microplastic Contamination in Wastewater Treatment Systems: A Strategic Review

“…In secondary treatment, microbes adhere to MP surfaces, secrete extracellular polymeric substances (EPSs), colonize the surface, and replicate to create biofilms [60]. This process disrupts microbial communities and interferes with biological treatment processes.…”

Recent advances in the relationships between biofilms and microplastics in natural environments

“…Because MPs are small and lightweight, they can act as vectors for microorganisms, facilitating the long-distance transport, especially in aquatic environments, which are susceptible to wind flows and water currents (Sun et al 2021 ; Sooriyakumar et al 2022 ). This introduces microorganisms attached to the MPs surface into new potential habitats, posing environmental and public health risks if biofilms harbor human and animal pathogens and/or invasive species (Frère et al 2018 ; Delacuvellerie et al 2022 ; Sooriyakumar et al 2022 ; Moyal et al 2023 ). Additionally, MPs can serve as active hotspots for horizontal gene transfer (HGT), i.e.…”

“…While HGT can occur naturally, MPs biofilms provide favorable conditions for genetic information transmission, with a high density of bacterial cells in a confined space and an active metabolic activity (Wang et al 2023 ). This can significantly increase the transfer of resistance genes, including those for heavy metals and antibiotics (Sun et al 2021 ; Laganà et al 2019 ; Moyal et al 2023 ). Particularly concerning is antibiotic resistance, attributed to the release of antibiotics into the environment and promotes the development of resistance in bacteria colonizing MPs (Atugoda et al 2020 ).…”

“…This approach also allows the identification of pathogens and study of the presence and/or abundance of genes responsible for antibiotic and heavy metals resistance, and virulence factors within the MPs biofilms. This research offers insights into the dissemination of pathogens and antimicrobial resistance, particularly relevant for public health (Nath et al 2023 ; Moyal et al 2023 ; Li et al 2024 ). Furthermore, since the plastisphere can harbor microorganisms involved in polymer degradation or organic pollutant absorption and/or degradation, the search of these specific functions and the quantification of the expression of related genes can provide interesting information for bioremediation purposes.…”

Tracking the Evolution of Microbial Communities on Microplastics through a Wastewater Treatment Process: Insight into the “Plastisphere”

“…However, this result is controversial, as some studies have indicated a decrease in microbial diversity with biofilm development [38,39], while others reported increased diversity in the presence of PS [40][41][42]. This discrepancy could be attributed to the "umbrella effect" of MPs on the survival and growth of microorganisms in wastewater, but their effects seem to be influenced by the chemical and physical properties of MPs, as well as environmental conditions [43][44][45]. It is plausible that the formation of an extracellular polymeric substance (EPS) plays a crucial role in the formation, stability, and functioning of microcolonies on the PS.…”