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| Main Authors: | , , , , |
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| Format: | Artículo científico |
| Language: | en |
| Published: |
Journal of hazardous materials
2026
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| Subjects: | |
| Online Access: | https://pubmed.ncbi.nlm.nih.gov/42013693/ |
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Table of Contents:
- High microplastic-microalga ratios facilitate the short-term growth and dissolved organic matter transformation of marine Porphyridium. Li, Huankai Zhang, Feng Miao, Fangfang Yang, Zhu Cai, Zongwei Porphyridium Microalgae Water Pollutants, Chemical Microplastics Photosynthesis Chlorophyll Current assessments of microplastic (MP) toxicity on microalgae often overlook the varying microplastic-to-microalgae (MM) ratios found in marine environments, potentially misinterpreting ecological risks. In the present study, we investigate whether adjusting MM ratios could alleviate photoinhibition and stimulate the short-term growth of marine microalgae Porphyridium cruentum, a species noted for its bounded exopolysaccharides (b-EPs). Contrary to the typical toxicity paradigm, we observed that high MM ratios (70 and 140) significantly improved short-term microalgal growth by up to 45.2% and alleviated photosynthetic pigment degradation relative to the control microalgae. Mechanistically, this growth promotion might be driven by a b-EP-mediated "self-protection" process: The C-O/C-O-C bond facilitated MP adsorption to b-EPs, enhancing b-EPs concentration in the high MM groups and promoting the aggregation and sedimentation of MPs. This process resulted in a 37% decrease in the original dissolved organic matter molecular formulas in the high MM groups, creating a low-oxidative habitat that favored initial survival. Crucially, the microalgae demonstrated remarkable plasticity under these extreme loads; in the MM140 group, cells compensated for MP-induced shading by significantly upregulating B-phycoerythrin (+57%), carotenoids (+42%), and chlorophyll a (+19%) to sustain photosynthesis. However, the short-term growth promotion and MP aggregates induced cell shading and phosphate limitation, suppressing photosynthesis-antenna proteins and downregulating DNA replication and nucleotide excision repair pathways-signaling potential long-term risks. This study provides a novel mechanistic understanding of MP-microalga interactions, proposing that microalgae can utilize b-EPs to mitigate acute MP stress at the expense of long-term integrity, a finding that reshapes our understanding of microalgal resilience in polluted oceans.