Anoxygenic Phototrophic and Related Sulfur-Cycling Prokaryotes from Lake Fryxell, McMurdo Dry Valleys, Antarctica

The data are in two forms, organismal and molecular. The former are
the results of enrichment culture experiments for the following groups
of organisms: anoxygenic phototrophic bacteria (purple and green
bacteria); sulfate-reducing bacteria; sulfur-oxidizing
chemolithotrophic bacteria. In some cases enrichment culture
experiments were negative, but in many others, cultures were obtained
and many of these are now pure (axenic) cultures. These organisms are
currently being characterized to define their basic properties. Many
turn out to be new species and some show distinct cold adaptation.
All are capable of growth at low temperatures. The molecular data are
the results of analyses of DNA isolated from permanently frozen
Antarctic lakes. Specific probes have been used that target the
phototrophic and sulfur-oxidizing bacteria described above. The
probes allow for analyses of diversity and metabolic activity of each
group of organisms with depth in the lake. Overal l, the results yield
a picture of the microbial diversity and activities of key bacteria
important to the ecology of permanently frozen lakes in the McMurdo
dry valleys.