Nearly a third of the microbes found in East Africa's Kabuno Bay oxidize dissolved iron. Photo by UBC
VANCOUVER, British Columbia, Sept. 9 (UPI) -- In the Democratic Republic of the Congo's Kabuno Bay lives a community of metal-eating microbes. Researchers say the organisms are the relatives of ancient bacteria that helped create Earth's iron ore deposits.
Earth scientists have fashioned a variety of theories for how the planet's oldest iron ore deposits came to be, but a new study by researchers at the University of British Columbia lends credence to the idea that iron-eating microbes played a role.
According to a new paper, published this week in the journal Scientific Reports, 30 percent of the microbes found in Kabuno Bay perform a special kind of photosynthesis -- oxidizing iron, instead of turning H2O or CO2 into oxygen, as algae and the leaves of plants do.
Researchers say the iron-oxidizing microbes offer a glimpse of what the marine environment of early Earth looked like. Prior to 2.3 billion years ago, oxygen was scarce but dissolved iron was plentiful. Scientists have theorized metal-eating bacteria converted the abundant iron into minerals that were then deposited out of the seawater.
Scientists say the microbes they found in East Africa process iron at a rate consistent with such a theory. The research also highlights the role ancient metal-eating microbes played in shaping the natural world.
"The bay is giving us real-world insight into how ancient varieties of photosynthesis may have supported Earth's early life prior to the evolution of the oxygen producing photosynthesis that supports life today," lead study author Sean Crow, a geomicrobiologist at UBC, explained in a press release.
In addition to helping form large ore deposits, the oxidation of rust helped grow the levels of oxygen in the atmosphere, enabling the development of more complex plants and animals.