GEBA project on Medical News Today

Genome scientists from the US and Germany have assembled the first pages of a comprehensive encyclopedia of genomes of all the microbes on Earth. The results, published Dec. 24 in the journal Nature, will help biologists find new genes and fill out the branches of the “Tree of Life.”

“This is a rich sampling of the diversity of microbial genomes,” said Professor Jonathan Eisen of the UC Davis Genome Center and the U.S. Department of Energy Joint Genome Institute, and senior author on the paper. “Better sampling across the tree of life gives you better reference points for predicting the functions of genes.”

There are estimated to be a nonillion — 1 followed by 30 zeroes — prokaryotic microbes on the planet. Unlike eukaryotic organisms such as people, yeast and oak trees, the cells of prokaryotes have no membrane wrapped around their DNA. They are divided into two major groups: Bacteria, including a tiny minority that make people sick, and the Archaea, which include organisms that can survive in extreme environments such as hot springs.

About a thousand prokaryote genomes have been sequenced to date, most of them among the small number that cause disease, or that do interesting things such as producing biofuels.

“That’s like making a map of the world and only mapping three cities,” Eisen said.