TY - JOUR

T1 - Calcium carbonate deposits and microbial assemblages on microplastics in oligotrophic freshwaters

AU - Kniggendorf, Ann Kathrin

AU - Nogueira, Regina

AU - Lorey, Corinna

AU - Roth, Bernhard

N1 - Funding Information: A.-K.K. received funding by the German Bundesministerium für Bildung und Forschung ( BMBF , Federal Ministry of Education and Research ) within the collaborative project OPTIMUS (13N13811) and by the Deutsche Forschungsgemeinschaft ( DFG , German Research Foundation )—Project ID 397827619. R.N. received funding by the Deutsche Forschungsgemeinschaft ( DFG , German Research Foundation )—Project ID 397827619. B.R. was funded by the Deutsche Forschungsgemeinschaft ( DFG , German Research Foundation ) under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453 ).

PY - 2021/3

Y1 - 2021/3

N2 - Microplastics are solid polymer particles with a wide variety of surface properties, found in most waterbodies, and known as carriers of distinct microbial communities affecting the fate of the particles in the environment. Little is known about the formation of mineral deposits on microplastics and how these deposits connect to microbial assemblages and affect the physicochemical properties of the particles. In addition, most of the available research on this topic is based on large microplastics with sizes between 100 μm and up to 5 mm, rather than the small microplastics often found in drinking water sources. To narrow this gap in our understanding of environmental effects on small microplastics, two types of small microplastics made of two distinct polymers, poly(methyl methacrylate) (PMMA) and poly(tetrafluoroethylene) (PTFE) with sizes ranging from 15 to 150 μm, were incubated for six months in unprocessed and processed drinking water with increasing ionic concentration to allow for the formation of mineral deposits and microbial assemblages. Spatially resolved analysis with fluorescent in situ hybridization and confocal Raman microscopic imaging revealed deposits of calcium carbonates and scattered microbial assemblages on all microplastics, with structure, extend, and microbial association with the carbonates depending on the respective microplastic. Notably, PTFE floatation was overcome after three months in unprocessed drinking water but remained unchanged in processed drinking water, whereas PMMA appeared unaffected, indicating that the fate of microplastics in the environment may depend on polymer type and the encountered aquatic conditions forming mineral and microbial attachments to the particle surface.

AB - Microplastics are solid polymer particles with a wide variety of surface properties, found in most waterbodies, and known as carriers of distinct microbial communities affecting the fate of the particles in the environment. Little is known about the formation of mineral deposits on microplastics and how these deposits connect to microbial assemblages and affect the physicochemical properties of the particles. In addition, most of the available research on this topic is based on large microplastics with sizes between 100 μm and up to 5 mm, rather than the small microplastics often found in drinking water sources. To narrow this gap in our understanding of environmental effects on small microplastics, two types of small microplastics made of two distinct polymers, poly(methyl methacrylate) (PMMA) and poly(tetrafluoroethylene) (PTFE) with sizes ranging from 15 to 150 μm, were incubated for six months in unprocessed and processed drinking water with increasing ionic concentration to allow for the formation of mineral deposits and microbial assemblages. Spatially resolved analysis with fluorescent in situ hybridization and confocal Raman microscopic imaging revealed deposits of calcium carbonates and scattered microbial assemblages on all microplastics, with structure, extend, and microbial association with the carbonates depending on the respective microplastic. Notably, PTFE floatation was overcome after three months in unprocessed drinking water but remained unchanged in processed drinking water, whereas PMMA appeared unaffected, indicating that the fate of microplastics in the environment may depend on polymer type and the encountered aquatic conditions forming mineral and microbial attachments to the particle surface.

KW - Biofilms

KW - Carbonates

KW - Fluorescence in situ hybridization

KW - Freshwater

KW - Microplastics

KW - Raman microscopy

UR - http://www.scopus.com/inward/record.url?scp=85096512354&partnerID=8YFLogxK

U2 - 10.1016/j.chemosphere.2020.128942

DO - 10.1016/j.chemosphere.2020.128942

M3 - Article

AN - SCOPUS:85096512354

VL - 266

JO - Chemosphere

JF - Chemosphere

SN - 0045-6535

M1 - 128942

ER -