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The University of Tennessee, Knoxville

Microbial Dark Matter: Life on Earth Just Got a Lot More Complicated

Karen G. Lloyd, Assistant ProfessorArts & Sciences - Microbiology

For hundreds of years, microbiologists have been growing as many different kinds of microbes as possible in petri dishes. Given this huge effort, it was assumed that most of the major branches of the tree of life had been discovered. However, now we have the technology to read the DNA sequences of every microbe in a drop of water or mud, on the back of our hands, or in a wastewater treatment plant. And, it turns out that we microbiologists have missed many of the large, deeply-rooted branches on the tree of life. These strange microbial cells are likely to be very different from any microbes we’ve ever known. I’ll show my lab’s newest estimates of how abundant they are in different environments, as well as one theory about why some of them have eluded all those efforts to grow them, and what they might be doing to help/hurt the Arctic.​

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