Hot Spring Bacteria Can Live Off Invisible Light Alone

Researcher studying cyanobacteria in hot springs have discovered that the potentially harmful algae can live in near-darkness, absorbing far-red light and converting it into energy while releasing oxygen. This is a major step forward towards better understanding the harmful algae blooms (HABs) that are occurring in Lake Erie and other lakes worldwide.

"We have shown that some cyanobacteria, also called blue-green algae, can grow in far-red wavelengths of light, a range not seen well by most humans," Donald A. Bryant, an experts of molecular biology at Penn State, said in a recent statement.

"Most cyanobacteria can't 'see' this light either," he added. "But we have found a new subgroup that can absorb and use it, and we have discovered some of the surprising ways they manipulate their genes in order to grow using only these wavelengths."

A study detailing this discovery was published in the Express edition of the journal Science.

According to the study, the cyanobacterial strain named Leptolyngbya completely changes how it conducts photosynthesis in order to use far-red light, which has wavelengths longer than 700 nanometers - longer than the range of light that most people can see.

Bryant says they achieve this by turning on a large number of genes to modify cellular metabolism and simultaneously turning off a large number of other genes . He and his team have named this process Far-Red Light Photoacclimation (FaRLiP).

This is big news, and HABs caused by cyanobacteria and similar algae have been making headlines, contaminating drinking water in Ohio and creating killer red-tide blooms in the Gulf of Mexico. When they aren't gathered en masse and causing problems, these bacteria are also seen as important carbon sinks, reducing the overall threat to Earth's ozone.

"It is important to understand how this photosynthetic process works in global-scale environments where cyanobacteria may be photosynthesizing with far-red light, in order to more fully understand the global impact of photosynthesis in oxygen production, carbon fixation, and other events that drive geochemical processes on our planet," Bryant said.