Marine bacteria in the wild organize into professions or lifestyle groups that partition many resources rather than competing for them, so that microbes with one lifestyle, such as free-floating cells, flourish in proximity with closely related microbes that may spend life attached to zooplankton or algae.
This new information about microbial groups and the methodology behind it could change the way scientists approach the classification of microbes by making it possible to determine on a large scale, relatively speaking, the genetic basis for ecological niches. Microbes drive almost all chemical reactions in the ocean; its important to identify the specific professions held by different groups.
This is the first method to accurately differentiate the ecological niche or profession among large groups of microbes in the ocean, said Professor Martin Polz, a microbiologist in MITs Department of Civil and Environmental Engineering. He and colleague Professor Eric Alm, a computational biologist, published a paper describing their research in the May 23 issue of Science.
The nature of reproduction in microbes makes it impossible to define populations based on the ability of individuals within a species to share genes, as we do with larger animals. Its only by determining bacterias ecological niche that scientists can classify them into populations. But microbes dont live in natural population groups when cultured in a lab. So scientists must catch bacteria in the wild, then examine them genetically to determine their lifestyle.
Most methods in use either over or underestimate greatly the number of microbial populations in a sample, leading either to a confusing array of populations, or a few large, but extremely diverse groups, said Polz. Erics method takes genetic information and groups the microbes into genetically distinct populations based on their preference for different habitats. Although this sounds like a simple pr
|Contact: Denise Brehm|
Massachusetts Institute of Technology, Department of Civil and Environmental Engineering