Unique Strategy of Microalgae to Tackle Global Warming

• 21 Oct 2023

A recently study suggests that microalgae, foundational organisms in the oceanic food chain and carbon dioxide capturers, employ an innovative strategy to adapt to global warming.

Key Points

• Harnessing Light-Responsive Proteins: As climate change depletes oceanic nutrient availability, marine microalgae, known as eukaryotic phytoplankton, activate a protein called rhodopsin.
• This protein, related to the human eye's light-sensing protein, assists the microalgae in thriving with the help of sunlight, replacing traditional chlorophyll.
• Role of Microbial Rhodopsins: Microbial rhodopsins are identified as significant light capturers in the ocean, potentially absorbing as much light as chlorophyll-based photosynthesis.
• Their precise role in these organisms remained unclear before this study.
• Impact of Global Warming on Nutrient Scarcity: Global warming, analogous to land drought, reduces surface water nutrients in the ocean.
• As surface waters warm, there's less mixing with nutrient-rich deeper waters, resulting in nutrient scarcity at the surface. This shortage affects primary producers like microalgae.
• Reduced Food Production and Carbon Capture: The scarcity of nutrients leads to algae producing less food and capturing less atmospheric carbon dioxide.
• In these regions, the capacity of algae to generate food and sequester carbon dioxide is significantly reduced, similar to decreased crop yields on land due to iron- and nitrogen-poor fertilizers.
• Harnessing Sunlight and Iron: Microalgae require sunlight for photosynthesis, but they also need ample iron to harness sunlight.
• However, about 35% of the ocean's surface lacks sufficient iron to support algae growth.
• The Southern Ocean, a vast iron-limited ecosystem, is particularly affected.
• Environmental Implications: The findings offer the potential to mitigate the adverse impacts of changing environmental conditions, including ocean warming and reduced crop productivity.
• This mechanism could also be applied to enhance the activity of light-independent microbes for various biotechnological purposes.