Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses

This study explores the combined toxicity of microplastics (MPs) and chromium (Cr6 +) on the freshwater green algae Scenedesmus obliquus. As emerging contaminants in aquatic ecosystems, MPs have been shown to intensify the toxicity of Cr6+, leading to a more significant impact on algal growth and bi...

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Main Authors: Luoxin Li, Jiani Yu, Yonghua Ma, Hui Tan, Fengxia Tan, Yi Chai, Hui Zhang
Format: Article
Language:English
Published: Elsevier 2025-02-01
Series:Ecotoxicology and Environmental Safety
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Online Access:http://www.sciencedirect.com/science/article/pii/S0147651325001496
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author Luoxin Li
Jiani Yu
Yonghua Ma
Hui Tan
Fengxia Tan
Yi Chai
Hui Zhang
author_facet Luoxin Li
Jiani Yu
Yonghua Ma
Hui Tan
Fengxia Tan
Yi Chai
Hui Zhang
author_sort Luoxin Li
collection DOAJ
description This study explores the combined toxicity of microplastics (MPs) and chromium (Cr6 +) on the freshwater green algae Scenedesmus obliquus. As emerging contaminants in aquatic ecosystems, MPs have been shown to intensify the toxicity of Cr6+, leading to a more significant impact on algal growth and biochemical responses than either stressor alone. A 30-day experimental simulation revealed that co-exposure to Cr6+ and 5 µm diameter polystyrene MPs resulted in significantly enhanced toxicity compared to individual exposures, characterized by a notable decrease in algal growth, diminished photosynthetic pigments, and protein content, alongside oxidative system damage. 100 nm MPs exhibited a distinct toxicity profile, with more pronounced effects when not combined with Cr6+, suggesting size-dependent interactions with algal cells. Transcriptomic analysis illuminated the complex regulatory mechanisms, indicating that toxicity primarily modulates metabolic pathways essential for photosynthesis, oxidative phosphorylation, the TCA cycle, and ribosome function in Scenedesmus obliquus. This study not only delineates the distinct toxicity effects of single and combined exposure systems but also emphasizes the need for a deeper understanding of the role of MPs in environmental pollution and their potential to modulate the toxicity of heavy metals in aquatic ecosystems.
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institution Kabale University
issn 0147-6513
language English
publishDate 2025-02-01
publisher Elsevier
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series Ecotoxicology and Environmental Safety
spelling doaj-art-7460dc6e4ced4a4b82046fb03e9670b52025-02-05T04:31:02ZengElsevierEcotoxicology and Environmental Safety0147-65132025-02-01291117813Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responsesLuoxin Li0Jiani Yu1Yonghua Ma2Hui Tan3Fengxia Tan4Yi Chai5Hui Zhang6Key Lab of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, CAFS, Wuhan 4302232, ChinaCollege of Animal Science and Technology, Yangtze University, Jingzhou 434025, ChinaCollege of Animal Science and Technology, Yangtze University, Jingzhou 434025, ChinaCollege of Animal Science and Technology, Yangtze University, Jingzhou 434025, ChinaCollege of Animal Science and Technology, Yangtze University, Jingzhou 434025, ChinaCollege of Agriculture, Yangtze University, Jingzhou 434025, China; Corresponding authors.Key Lab of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, CAFS, Wuhan 4302232, China; Corresponding authors.This study explores the combined toxicity of microplastics (MPs) and chromium (Cr6 +) on the freshwater green algae Scenedesmus obliquus. As emerging contaminants in aquatic ecosystems, MPs have been shown to intensify the toxicity of Cr6+, leading to a more significant impact on algal growth and biochemical responses than either stressor alone. A 30-day experimental simulation revealed that co-exposure to Cr6+ and 5 µm diameter polystyrene MPs resulted in significantly enhanced toxicity compared to individual exposures, characterized by a notable decrease in algal growth, diminished photosynthetic pigments, and protein content, alongside oxidative system damage. 100 nm MPs exhibited a distinct toxicity profile, with more pronounced effects when not combined with Cr6+, suggesting size-dependent interactions with algal cells. Transcriptomic analysis illuminated the complex regulatory mechanisms, indicating that toxicity primarily modulates metabolic pathways essential for photosynthesis, oxidative phosphorylation, the TCA cycle, and ribosome function in Scenedesmus obliquus. This study not only delineates the distinct toxicity effects of single and combined exposure systems but also emphasizes the need for a deeper understanding of the role of MPs in environmental pollution and their potential to modulate the toxicity of heavy metals in aquatic ecosystems.http://www.sciencedirect.com/science/article/pii/S0147651325001496MicroplasticsChromiumCombined exposureScenedesmus obliquusTranscriptomic analysis
spellingShingle Luoxin Li
Jiani Yu
Yonghua Ma
Hui Tan
Fengxia Tan
Yi Chai
Hui Zhang
Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
Ecotoxicology and Environmental Safety
Microplastics
Chromium
Combined exposure
Scenedesmus obliquus
Transcriptomic analysis
title Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
title_full Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
title_fullStr Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
title_full_unstemmed Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
title_short Microplastic-enhanced chromium toxicity in Scenedesmus obliquus: Synergistic effects on algal growth and biochemical responses
title_sort microplastic enhanced chromium toxicity in scenedesmus obliquus synergistic effects on algal growth and biochemical responses
topic Microplastics
Chromium
Combined exposure
Scenedesmus obliquus
Transcriptomic analysis
url http://www.sciencedirect.com/science/article/pii/S0147651325001496
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