Figure 5. Uptake and release of putatively identified metabolites by individual isolates.

The results show a potential for competition for a small groups of metabolites (only taken up by isolates and not released) as well as potential for cross feeding (metabolites released by at least one isolate and taken up by at least one other isolate). Some metabolites were released by isolates, not taken up by any other isolate but depleted by authentic biocrusts suggesting the presence of other microorganisms in the biocrust able to use these metabolites.