An international team of researchers has shown how anaerobic microbes in oil deposits around the world — including in unconventional sources such as the oil sands — naturally break down crude oil into methane in the reservoir. (greencarcongress.com)
On the other hand, many anaerobic microbes including methanogens are easily poisoned by oxygen, and the recent discovery of banded sediments with rusted iron on Akilia Island in West Greenland suggests that oxygen - producing, photosynthetic microbes (e.g., cyanobacteria) living on the surface of wet areas to gather sunlight may have developed by the end of this geologic period (3.85 billion years ago) despite continuing bombardment from space. (members.nova.org)
Instead of mitochondria (the cellular engines that convert oxygen to energy, present in all other known animal cells), these creatures contain structures resembling hydrogenosomes, the organelles that anaerobic microbes use to generate energy. (discovermagazine.com)