Characterization of microbial assemblages on micro-plastics in a river system

Characterization of microbial assemblages on micro-plastics in a river system

Thuto Magome (MSc), Carlos Bezuidenhout, Charlotte Mienie
Commenced 2020

The distribution and quantity of microplastics in the aquatic system is alarming. A growing concern from a microbial point of view is that, microplastics can be colonized by different microbial organisms which may include pathogens. This association may originate from different sources across the river system including effluent from wastewater treatment plants (WWTPs). The aim of the study is to detect and characterize microorganisms colonizing microplastics in a river system particularly those potentially originating from WWTPs. Furthermore, to investigate the formation of biofilm formation on microplastics and to detect the presence and levels of selected antibiotic resistance genes such as AmpC β-lactamase . Sampling will be conducted in the North-West Mooi River sites (upstream , JB Marks Wastewater treatment plant and downstream).

•    Isolation of microplastics in a river system
•    Characterization of microbials on microplastics from environmental microplastic samples
•    To characterize microbial consortia on microplastics in WWTe v/s river water 
•    Quantification of AmpC β-lactamase genes from eDNA extratacted from microplastics

Expected outcomes
Presence of microplastics within the river stream. 
We expect to see a difference in microbial community on microplastics in comparison with the free-floating microbial community. We also expect to see a difference in microplastics quantity in the upstream site (METSI) and downstream the JB Marks WWTP
Benefit to interdisciplinary objectives of the UESM
The study aims at addressing microplastics pollution in aquatic systems, specifically freshwater which is also used for drinking purposes in most rural areas. Aims to provide awareness for monitoring microplastic pollution in freshwater systems

Project status
Not yet completed
View preliminary results here.
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Sampling sites and land cover activity dominance Microplastics isolated from river water Microplastic fibre viewed under a stereomicroscope at 40X magnification versus under the scanning electron microscope at 20 µm. Relative abundance of the top 20 most abundant phyla based on 16S rRNA metabarcoding for taxonomic composition from microplastic (MP) and water (W) samples from each respective site.


Last updated: 11 November 2022