SS2.04 Microbial Stoichiometry and Impacts on Biogeochemistry: From Genes to the Biosphere
Date: Friday, June 14, 2002
Time: 9:00:00 AM
Location: Carson C
 
ForemanCM, Montana State University, Bozeman, USA, cforeman@montana.edu
Wolf, C, F, Montana State University, Bozeman, USA, cwolf@montana.edu
Priscu, J, C, Montana State University, Bozeman, USA, jpriscu@montana.edu
 
EXTRACELLULAR ENZYME ACTIVITIES: STRATEGIES FOR SURVIVAL IN PERMANENTLY ICE-COVERED LAKES IN THE MCMURDO DRY VALLEYS OF ANTARCTICA.
image
The lakes of the McMurdo Dry Valleys, Antarctica, lack metazoans providing a unique environment in which to study microbial processes. These permanently ice-covered lakes exist in the coldest, driest desert in the world and are intensely stratified and distinctly different from one another in their physical, chemical and biological processes. We examined extracellular enzyme activities associated with C, N, and P acquisition to understand the growth constraints imposed by organic carbon and inorganic nutrients. Alkaline phosphatase activity in Lakes Bonney, Hoare and Fryxell differ by one to two orders of magnitude, associated with phosphorous deficiency. Other enzymes show distinct patterns related to carbohydrate and protein availability. The data also suggest that the microbes have multiple kinetic systems affording them an advantage in these lakes.