Ancient bacteria genome reconstructed from Neanderthal tooth gunk

Microbial DNA stored in ancient human and Neanderthal teeth has been used to reconstruct molecules produced by ancient bacteria. This approach could help discover new antibiotics and other useful molecules from microorganisms that may have gone extinct thousands of years ago.

Researchers are typically sent to tropical islands and hydrothermal vents to look for unknown microbes. Pierre Stahlfors and his colleagues at Friedrich Schiller University Jena in Germany went hunting back in time. They looked at microbial DNA preserved in calcified dental plaque from 34 of his ancient humans and 12 of his Neanderthals, including those 102,000 years old.

Ancient DNA was fragmented into millions of short, often fragmented sequences. Assembling these into a sufficiently complete genome is a “multidimensional jigsaw puzzle,” he says, Stallforth.

From nine specimens, the researchers were able to piece together the high-quality genomes of two previously unknown species of green sulfur bacteria in this genus. ChlorobiumThe species may be unknown, researchers say, because living specimens had never been sequenced before or are now extinct.

Chlorobium Since the seeds are not normally part of the oral microbiome, Stallforth speculates that the bacteria may have entered the specimen’s mouth via contaminated drinking water.

Many microbial genomes have been reconstructed, at least in part, from ancient DNA, but researchers have taken these things one step further. From them he inserted a cluster of three genes. Chlorobium Transform the genome into a living bacterium to synthesize molecules that ancient bacteria would have made.

The researchers named the resulting molecule “paleofuran.”Comparing the Genes Used to Make Paleofuran to Modern Genes Chlorobium Stallforth says, suggesting that the molecule may be involved in regulating photosynthesis in bacteria. “I found a simple natural product.”

Paleofuran by itself is unlikely to have useful uses, but Hendrik Poinar of McMaster University in Canada is taking advantage of ancient microbial diversity to develop new molecules that may serve antibiotics and other purposes. It claims to provide a proof of concept that it can be discovered.

“Many microbial diversity may have become extinct, or at least postponed, due to pressure from antimicrobial resistance,” he says. I’m not looking at it today.”

But Claudiu Supuran of the University of Florence, Italy, is skeptical that going back in time is the best way to discover innovative new molecules. “There are so many potential genome mining and engineering strategies for living organisms today.”