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.