We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Not so dangerous? PET microplastics toxicity on freshwater microalgae and cyanobacteria
AI summary Read the abstract
Researchers tested whether PET microplastics are toxic to freshwater algae and cyanobacteria and found that the effects were relatively mild compared to other plastic types. While PET particles did cause some changes in growth and photosynthesis at high concentrations, the organisms largely tolerated the exposure. The study suggests that not all microplastics are equally harmful, and PET may pose lower risks to aquatic primary producers.
Microalgae and cyanobacteria are among the most important primary producers and are responsible for the production of 50-80% of the oxygen on Earth. They can be significantly affected by plastic pollution, as the vast majority of plastic waste ends up in rivers and then the oceans. This research focuses on green microalgae Chlorella vulgaris (C. vulgaris), Chlamydomonas reinhardtii (C. reinhardtii), filamentous cyanobacterium Limnospira (Arthrospira) maxima (L.(A.) maxima) and how they are affected by environmentally relevant PET-MPs (polyethylene-terephtalate microplastics). Manufactured PET-MPs have asymmetric shape, size between 3 and 7 μm and were used in concentrations ranging from 5 mg/L to 80 mg/L. The highest inhibitory rate of growth was found in C. reinhardtii (-24%). Concentration-dependent changes in chlorophyll a composition were found in C. vulgaris and C. reinhardtii, not in L. (A.) maxima. Furthermore, cell damage was detected in all three organisms by CRYO-SEM (shriveling, cell wall disruption), but the cyanobacterium was the least damaged. A PET-fingerprint was detected on the surface of all tested organisms using FTIR, indicating the adherence of PET-MPs. The highest rate of PET-MPs adsorption was detected in L. (A.) maxima. Specifically, characteristic spectra were observed at ∼721, 850, 1100, 1275, 1342, and 1715 cm which are specific for functional groups of PET-MPs. Nitrogen and carbon content significantly increased in L. (A.) maxima under exposure to 80 mg/L due to the PET-MPs adherence and mechanical stress. In all three tested organisms, weak exposure-related ROS generation was detected. In general, cyanobacteria seem to be more resistant to the effects of MPs. However, organisms in the aquatic environment are exposed to MPs over a longer time scale, so it is important to use the present findings for further longer-term experiments on environmentally relevant organisms.
More Papers Like This
Molecular mechanisms by which polyethylene terephthalate (PET) microplastic and PET leachate promote the growth of benthic cyanobacteria
AI summary Read the abstract
Researchers found that PET microplastics and the chemicals they release into water promoted the growth of toxic bottom-dwelling algae by 39-63%, which in turn increased harmful toxin levels in the water. This is concerning for human health because these toxins threaten drinking water safety, and microplastics accumulating at the bottom of lakes and rivers are making the problem worse.
Effects of polyethylene terephthalate microplastics on cell growth, intracellular products and oxidative stress of Scenedesmus sp.
AI summary Read the abstract
Researchers exposed freshwater microalgae to PET microplastics, a common plastic found in beverage bottles and textiles. Higher concentrations of PET particles significantly reduced algal growth and disrupted the cells' internal production of lipids, carbohydrates, and proteins. The study suggests that PET microplastic pollution in wastewater could harm the tiny organisms that form the foundation of aquatic food webs.
Interaction between polyethylene terephthalate (PET) microplastic and microalgae (Scenedesmus spp.): Effect on the growth, chlorophyll content, and hetero-aggregation
AI summary Read the abstract
Researchers exposed two types of freshwater microalgae to PET microplastics at various concentrations, finding that higher levels significantly stunted growth, reduced chlorophyll, and caused the algae to cluster around the plastic particles. This "hetero-aggregation" behavior suggests microplastics can physically trap microalgae, potentially disrupting aquatic food webs that depend on algae as a foundation.
Contrasting the effects of microplastic types, concentrations and nutrient enrichment on freshwater communities and ecosystem functioning
AI summary Read the abstract
Researchers tested two types of microplastics, conventional polyethylene and biodegradable polylactic acid, in outdoor freshwater mesocosms and found that neither type significantly affected community composition or ecosystem functions like algae growth and leaf decomposition. Even at concentrations known to cause harm in lab settings, the microplastics had minimal impact when tested in more realistic ecological conditions. The study suggests that real-world microplastic effects on freshwater communities may differ from laboratory predictions.
Comparative growth and cellular responses of toxigenic Microcystis exposed to different types of microplastics at various doses
AI summary Read the abstract
Researchers exposed toxigenic Microcystis cyanobacteria to polyethylene and polyvinyl chloride microplastics at various concentrations to study dose- and time-dependent effects. They found that low microplastic doses initially stimulated growth, while higher doses increasingly inhibited it, with PVC showing stronger effects than polyethylene. The study suggests that microplastic pollution in freshwaters could influence the behavior of harmful algal blooms depending on the type and concentration of plastic present.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.