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Molecular Probe Optimization to Determine Cell Mortality in a Photosynthetic Organism Microcystis aeruginosa Using Flow Cytometry
Published on: January 29, 2016
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How does Microcystis aeruginosa respond to elevated temperature?
Yongqi Guo1, Han Meng1, Sichuan Zhao2
1School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China.
The Science of the Total Environment
|May 21, 2023
Summary
Elevated temperatures promote the growth and toxicity of Microcystis aeruginosa, a key freshwater cyanobacterium. Global warming may intensify harmful algal blooms by accelerating its life cycle and increasing toxin production.
Area of Science:
- Environmental Microbiology
- Aquatic Ecology
- Phycology
Background:
- Cyanobacteria, particularly Microcystis aeruginosa, are prevalent in freshwater ecosystems.
- Water temperature significantly influences the life cycle and proliferation of M. aeruginosa.
- Understanding M. aeruginosa's response to temperature is crucial for managing harmful algal blooms.
Purpose of the Study:
- To investigate the physiological and metabolic responses of M. aeruginosa across a simulated annual temperature cycle (4-35°C).
- To determine the optimal temperature ranges for M. aeruginosa growth, extracellular polymeric substance (TEPS) production, and microcystin (MC) secretion.
- To assess the impact of elevated temperatures on key metabolic enzymes and genes involved in M. aeruginosa's life cycle.
Main Methods:
- Culturing M. aeruginosa under controlled temperature conditions simulating overwintering, recruitment, and rapid growth phases.
- Measuring cell density, total extracellular polymeric substance (TEPS) concentration, and actual quantum yield of photosystem II (Fv'/Fm').
- Analyzing the expression of photosynthetic enzymes (RuBisCO, FBA) and the mcyB gene under varying temperatures.
Main Results:
- M. aeruginosa growth recovery observed at 4-8°C post-overwintering, with recruitment at 16°C.
- TEPS concentration and microcystin (MC) secretion peaked at 15-25°C.
- Optimal growth temperature for M. aeruginosa was determined to be 20-25°C, with rapid cell density increase from 26-35°C.
- Key photosynthetic enzymes and the mcyB gene were found to be temperature-sensitive.
Conclusions:
- Temperature is a critical driver for the annual cycle of M. aeruginosa, influencing its growth, TEPS production, and MC toxicity.
- Projected global warming scenarios suggest earlier M. aeruginosa recruitment, extended growth periods, and increased bloom intensity.
- Findings highlight the need for proactive water resource management strategies to mitigate the impacts of climate change on cyanobacterial blooms.
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