|Harwood, Caroline - UNIV OF IOWA|
Submitted to: Federation of European Microbiological Societies Microbiology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 5, 1999
Publication Date: N/A
Interpretive Summary: Many bacteria are motile, and they respond to their environment by migrating to an area that has the best conditions for survival and growth. This behavior is called chemotaxis when bacteria swim toward nutrients or away from toxic substances. Bacteria can also swim to an area with the most favorable concentration of oxygen; this behavior is termed aerotaxis. We identified a gene for aerotaxis in the bacterium Pseudomonas putida. This work contributes to our understanding of how bacteria respond to stimuli. These results will help us understand how bacteria live and grow in natural environments, where bacteria play important roles in the turnover of naturally-occurring compounds such as plant material, and in the removal of man-made compounds that may be pollutants.
Technical Abstract: An aerotaxis gene, aer, was cloned from Pseudomonas putida PRS2000. A P. putida aer mutant displayed an altered aerotactic response in a capillary assay. Wild-type P. putida clustered at the air/liquid interface. In contrast, the aer mutant did not cluster at the interface, but instead formed a diffuse band at a distance from the meniscus. Wild-type aer, provided in trans, complemented the aer mutant to an aerotactic response that was stronger than wild-type. The P. putida Aer sequence is similar over its entire length to the aerotaxis (energy taxis) signal transducer protein, Aer, of Escherichia coli. The amino terminus is similar to redox-sensing regulatory proteins, and the carboxy terminus contains the highly conserved domain present in chemotactic transducers.