The Extensive Diversity of the Prokaryotes even in Extreme Environments
Rainey, F.A.
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, U.S.A.
The description of certain environments as "extreme" results from the perception of environmental conditions that are considered normal to be those that are capable of supporting life. Extreme environments contain conditions at the limits either side of the physiological normal. Environments exhibiting extremes of pH, temperature and salinity or combinations of these fall into the extreme environment category. The isolation and detection of prokaryotes in such environments has established the presence of life in extreme environments. Water activity or the lack of it is one physical parameter that has not been studied in detail with respect to the survival of microorganisms in extreme environments. The earth's dry or arid lands represent natural environments with low water activity and as such can be considered extreme environments. Many of these hyper-arid regions are devoid of higher eukaryotic life forms but yet harbor extensive prokaryotic diversity. Many of these!
environments represent relic environments of ancient lakes or oceans. These hyper-arid environments represent the closest analog to Martian environmental conditions. Study of the prokaryotic diversity both cultured and uncultured [1] gives us an insight into the microbial components of these environments. Many of the bacteria isolated from these hyper-arid environments not only survive desiccation but are resistant to ionizing radiation and could constitute a resource of model microorganisms for future investigations of survival under extreme extraterrestrial conditions.
[1.] Rainey, F. A., E. I. Friedmann, and E. Stackebrandt (1997) Prokaryotic diversity assessment of a dry desert soil using culturing and non-culturing approaches. Abstract, 97th General Meeting of the American Society for Microbiology, Miami Beach, May 4-8.
| LOCATION |
DATE |
TIME |
| Lecture Hall I |
Tuesday, April 7 |
06:00 pm |