The Metagenomic Frontier

There's nothing like an emerging field of science to fire up the imagination -- and given our recent run of bacteria posts, it's only appropriate that it involves microbes. The science is called metagenomics, and a recent National Research Council report says it's "the greatest opportunity -- perhaps since the invention of the microscope -- to revolutionize understanding of the microbial world."

Metagenomics promises to analyze not just a few types of bacteria at a time, studied in isolation from each other, but whole communities. Until now, this hasn't been done; as a result, we know that bacteria are essential for about every living process, from the organismal level on up to the planetary scale, but little about how they interact.

"Metagenomics lets us see into the previously invisible microbial world, opening a frontier of science that was unimaginable until recently," said Jo Handelsman, Howard Hughes Medical Institute Professor, departments of plant pathology and bacteriology, University of Wisconsin, Madison and co-chair of the committee that wrote the report. "Shedding light on thousands of new microorganisms will lead to new biological concepts as well as practical applications for human health, agriculture, and environmental stewardship."

Metagenomics studies begin by extracting DNA from all the microbes living in a particular environmental sample; there could be thousands or even millions of organisms in one sample. The extracted genetic material consists of millions of random fragments of DNA that can be cloned into a form capable of being maintained in laboratory bacteria. These bacteria are used to create a "library" that includes the genomes of all the microbes found in a habitat, the natural environment of the organisms.

Since metagenomics as described here involves only the creation of genome libraries that can help identify bacteria present at a given time and place, it's probably a bit premature to say it will "revolutionize" everything. Knowing what we're looking at isn't the same as knowing how it fits together. But revolutions begin with knowledge, and this is a necessary first step.

New Science of Metagenomics 'Will Transform Modern Microbiology' [National Academies of Science]

Image: Alan Moore