Scientists have discovered a new type of efficient photosynthesis that allows organisms living in bleak, low-light conditions to create energy and thrive.
The discovery could potentially help future space colonizers survive in outer worlds by harnessing the power of low-light photosynthesis to create an atmosphere conducive to human life.
Photosynthesis That Uses Near-Infrared Light
An international team of researchers headed by biochemists at the Imperial College London learned that a wide range of cyanobacteria, a blue-green algae found in freshwater lakes, can produce the phytochemicals essential for survival through photosynthesis even when subjected to low-light conditions by using near-infrared light instead.
The team detected the same ability in cyanobacteria located in cultures growing at Yellowstone, on rocks at the beach in Australia, or even in a small cupboard inside a lab in London.
What Is Photosynthesis?
Plants use the process of photosynthesis to harness light from the sun and turn it into oxygen and energy. Before this study, scientists believed photosynthesis relied on the existence of a green pigment called chlorophyll-a. Chlorophyll-a plays a central role in the process as it collects visible red light and uses it to produce oxygen and nutrients.
Red light was once thought to be the lowest minimum requirement for photosynthesis to occur. Astrobiologists used what is called the red light limit to assess if a certain planet has the potential to harbor complex life. The new discovery, published in Science, upends all that.
"This is textbook changing stuff," says lead author Bill Rutherford of the Department of Life Sciences at Imperial.
Near-Infrared Photosynthesis
When the researchers exposed cyanobacteria to near-infrared light, the systems using standard photosynthesis shut down, giving way to a new type of photosynthesis that uses a different type of chlorophyll called chlorophyll-f.
Chlorophyll-f is a red pigment that can absorb near-infrared light. The researchers found that what was once relegated to the periphery as an accessory was actually efficient at harvesting near-infrared light and producing energy.
What is more surprising is the process is actually widespread in low-light areas rich in infrared light. In fact, this new type of photosynthesis could very well be happening in one's own backyard.
Useful For Space Exploration
The researchers believe their discovery could redefine humanity's search for new worlds to inhabit and extraterrestrial life forms.
Bacteria that can produce oxygen in harsh conditions could be used to create a livable atmosphere for humans colonizing new planets.
This particular bacteria has been around for 2.5 billion years and has survived the extreme environments of the Mojave Desert, Antarctica, and even the International Space Station.
"Photosynthesis could theoretically be harnessed with these types of organisms to create air for humans to breathe on Mars," says chemist Elmars Krausz of the Australian National University, who is also part of the study.
The researchers believe their findings could also help astronomers look for signs of life in outer space by looking for the signature fluorescence of chlrophyll-f.
