Microorganisms in colder climates darken themselves to capture more heat from the sun and improve their ability to survive, according to a study from scientists at Johns Hopkins Bloomberg School of Public Health.
The scientists, in a study to be published in Current Biology on August 2, examined yeasts collected at different latitudes, and found that dark-pigmented ones were more frequently found away from the Tropics. Dark-pigmented microbes also maintained higher temperatures under a given amount of light, and in cold conditions had a clear growth advantage over their unpigmented counterparts.
Countless pigmented fungi, bacteria and other microbial communities exist at cold latitudes, so it is at least conceivable that their passive solar heating mechanism collectively has an impact on climate.
“Our results suggest that pigmentation is an ancient adaptation mechanism for obtaining heat from solar radiation and could be an important variable in modeling climate change,” says senior author Arturo Casadevall, MD, PhD, the Alfred & Jill Sommer Professor and Chair of Molecular Microbiology and Immunology at Johns Hopkins Bloomberg School of Public Health.