Prophage

JAMS Meeting Report – April 2012
by Thomas Jeffries
 
There was a good turnout on ANZAC day eve for three interesting talks, pizza and free local beer.
 
Kicking off the evening was John Lee, from the University of Georgia, with his ambitiously titled talk “Bioluminescence: The First 3000 Years”.  After a historical introduction to the long running observation of bioluminescence, via the discovery in 1672 that oxygen was necessary for bacterial luminescence, John told us how it was determined that bioluminescence is an enzyme mediated chemical reaction involving “luciferase” and "luciferine". In the modern age of biochemistry it was determined that ATP is the substrate in this reaction.  Following the elucidation of the structure of firefly luciferase in 1959, modern techniques (i.e. picosecond dynamic fluorescence spectroscopy and NMR) have allowed researchers to uncover the enzymes and processes involved in bioluminescence.  One of the most important of these enzymes Green-fluorescent protein (GFP) was discovered in jellyfish by Shimomura (who evidently has a lab at his house!) and led to his Nobel prize in 2008.  Due to GFP’s widespread use in research, it is regarded as one of the most important proteins in science.
 

Event Date: 
Tuesday, April 24, 2012 - 19:15 - 20:00
Institution: 
Nanyang Technological University, Singapore / UNSW
Title: 

The Great Escape: Biofilm formation and dispersal

Abstract: 

Bacteria form biofilms on almost all surfaces, ranging from ship hulls to cooling towers, to indwelling biomedical devices.  Biofilms also play positive roles, for example, floc and granule formation for the biological remediation of contaminated water.  Therefore, there is strong drive to understand the processes of biofilm formation, to either eliminate biofilm formation in some industrial processes and human health, or to encourage their formation, for processes such as remediation.  To develop innovative, environmentally friendly, biofilm control technologies, it is essential to understand the process of biofilm formation and how bacteria control the process of dispersal. 
Bacteria rapidly respond to changes in nutrient conditions, and we have shown that depletion of nutrients, e.g. carbon limitation or nitrogen, can lead to dispersal of bacterial biofilms.  This process is mediated via an intracellular second messenger cascade, using cAMP and c-di-GMP and may also be linked to other physiological signals such as nitric oxide mediated dispersal. 
We have also shown that biofilm development and dispersal is dependent on a prophage carried by Pseudomonas aeruginosa.  The phage plays an important role in multiple aspects of biofilm development and stability and we are beginning to unravel the mechanisms result in phage conversion which ultimately are linked to biofilm development.

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