Bad neighbours, antisocial behaviour, and party animals; the secret life of microbes

In this talk, I'll take a look at three "microbial vignettes". In the first, I'll examine how the presence of co-habiting microbes profoundly affects the biology of a human pathogen, Pseudomonas aeruginosa. This is important, because in diseased human airways - where P. aeruginosa is an unwelcome, but common inhabitant - the pathogen invariably shares the infection site with a variety of other microbes. It turns out that these microbial neighbours interact with one another and that these interactions are perturbed by the loss of a quorum sensing "master regulator" (LasR) in P. aeruginosa. In the second "short", I'll talk about how we are now able to manipulate the rate of evolution of the organism, either by "stepping on the gas pedal" or by "slamming on the brakes". The ability to do this, in an experimentally-controlled manner, is allowing us to access some novel evolutionary trajectories, and to address some truly fundamental biological questions. Finally, I'll take a fresh look at bacterial biofilms and in particular, examine whether the exopolysaccharide "bioglue" that holds these structures together might have additional - possibly more important roles. It turns out that it does, and that the exopolysaccharide matrix acts as a "net" to selectively sequester secreted proteins, potentially conferring novel functionalities on the biofilm.

Brief Speaker Bio. 
After reading for a degree in Biochemistry at the University of Oxford, Martin completed a PhD on bacterial chemotaxis at the Weizmann Institute of Science (Israel), where he was awarded the Wolf Prize for his contributions to the field. Leavuing Israel with a PhD and a [German] wife, he then moved to Toulouse (supported by a long-term EMBO fellowship) where he learned the dark art of x-ray crystallography and solved the structure of a signaling complex involved in bacterial chemotaxis. He then moved back to the UK to take up a post-doctoral position at the University of Cambridge working on quorum sensing in the fascinating plant pathogen, Pectobacterium atrosepticum. There, he developed skills in molecular genetics and demonstrated (for the first time) that quorum sensing molecules bind directly to their cognate LuxR homologs in a range of bacteria. This advance allowed him to secure a Royal Society University Research Fellowship to start his own group - where he learned the hard way that prospective students don't like any project with the word "plant" in, and when offered projects on the plant pathogen versus a mammalian pathogen, always went for the latter. Since around 2000, his team's focus has been on understanding better the link between metabolism and virulence in the opportunistic human pathogen, Pseudomonas aeruginosa. He is now Professor of Microbial Physiology and Metabolism at the University of Cambridge.