Antarctic microbes scavenge their metabolic fuel from the air around them
On a planet where live evolved around access to water, living in a desert is a challenge. Plants and animals that call these arid locations home often require impressive adaptations, like thorns and thick skin, to make the most of the resources available. As impressive as any of those adaptations are, scientists recently discovered that microbes may be the true masters of inhospitable biomes, making their homes in the coldest, darkest desert on Earth— the Antarctic. The various bacteria living in the icy terrain not only contend with a lack of water, but very low levels of carbon in the soil and a lack of photosynthesis-powering sunlight for half the year. With all these common sources of nutrients missing, it almost seemed liked the microbes were magically pulling their sustenance out of thin air.
As it turns out, the microbes were doing exactly that. The most reliable source of carbon and energy in the Antarctic is apparently the air itself. The microbes have evolved mechanisms to harvest what they need from hydrogen and carbon monoxide circulating in the atmosphere. It’s obviously not the most robust way to spur growth, but it seems to be the primary source of nutrition and energy for the microbes growing in locations where no plant could even hope to live.
Applications beyond Antarctic bacteria
The surprising diet these bacteria live off of raises two new lines of inquiry. While scavenging the air itself doesn’t appear to be the most energy-rich way to live, understanding how the bacteria accomplish this task may open up new technologies that don’t require traditional power sources.
It also lowers the bar for what life needs to sustain itself, particularly on other planets. Our search for extraterrestrial life generally focuses on ingredients that are found across wide portions of the Earth. There’s been some understanding of the extreme environments microbes can live in, such as along hydrothermal vents, but surviving on wafting carbon monoxide certainly expands our notion of what qualifies as ‘habitable.’
Source: Living on thin air—microbe mystery solved, Phys.org
