Tuesday, November 14, 2006 - 2:45 PM
202-13

Live Reports from the Soil Grain -- the Promise and Challenge of Microbiosensors.

Zoe Cardon, Patrick Herron, Catalina Arango Pinedo, Zane Haider, and Daniel Gage. Univ of Connecticut, Dept of Ecology and Evolutionary Biology, 75 North Eagleville Road, U-3043, Storrs, CT 06269

Genetically engineered bioreporter bacteria (microbiosensors) are particularly promising in their ability to provide continuous, in situ temporal and spatial information about resource availability, conditions, and microbial responses at the scale of individual microbes in soil.  Microbiosensors link expression of known genes with production of a report (e.g. a protein, or light) that can be assayed.  Challenges emerge in interpretation of the report because it is not the end product of a single process, but rather it represents the net result of promoter activity, protein folding and degradation rates, and bacterial growth rates.  Further, bioreporters are living cells, so the biology of the host organisms (e.g. substrate preferences) can influence the responses of the reporter.  Interpretation of reports must therefore be conservative.  Even with this limitation, the information gained at microbial scales never before assayed is powerful.  As examples, microbiosensors reporting gradients in conditions and microbial responses (e.g. water potentials and microbial growth rates) around roots at mm spatial scales, in situ, will be presented.