Instead of sequencing the genome of one organism, why not sequence a drop of sea water, a gram of farm soil or even a sunken whale skeleton? Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg and their US collaborators have done just that, and the result is a new appreciation for the rich diversity of life that exists in the most unlikely places (Science, April 22, 2005).
Bacteria make up the greatest mass of life on earth by far and play a crucial role in the lives of all other organisms. But scientists have only touched the tip of the iceberg when it comes to identifying bacteria 99% of species cannot be grown by standard techniques in the laboratory. The emerging field of "metagenomics" is rapidly giving researchers a view of how diverse microbial life really is. Instead of analyzing the genome of a specific organism, scientists sequence the DNA from environmental samples such as the ocean or soil. For the first time, this gives them a clear picture of the diversity of life in these habitats.
"These studies were simply not possible before," says Peer Bork, the EMBL scientist responsible for the data analysis in the project. "And future applications for this type of technology are endless, from giving farmers insight into their soil to fighting bacterial contamination in hospitals to characterizing microbes in a patient's mouth."
In the current study, Bork worked with EMBL scientist Christian von Mering and US collaborators to analyze two very different samples: whale skeletons from the bottom of the ocean floor and soil from a farm in the USA. Sunken whale skeletons are a lipid-rich nutrient source that can foster the growth of a flourishing ecosystem that contains specialized bacteria, whereas soil is an example of a complex microbial environment that can contain more than 3000 distinct spec
Contact: Trista Dawson
European Molecular Biology Laboratory