Condensed Matter & Surface Sciences

COLLOQUIUM

Hanna Salman

University of Pittsburgh

"Population Effects on Bacterial Thermotaxis"

We have developed new methods to explore the response of E. coli to temperature changes. A strong correlation between the population density and the response to a temperature gradient is observed. Bacteria that are grown below a critical concentration, in batch-mode cultures, swim towards warm regions when subjected to a temperature gradient. Above that concentration, they swim towards colder regions. Our findings indicate that a secreted intercellular signal, glycine, mediates this switch through methylation of Tsr receptors. At high bacterial concentration, the switch is reinforced by an inversion of the Tar/Tsr expression ratio.

Thursday, May 8, 2008

4:10 p.m. -- Walter Lecture Hall 245