September 2013

Event Date: 
Wednesday, September 25, 2013 - 06:00 - 06:15
Institution: 
UNSW
Title: 

Viral infections of Ecklonia radiata

Abstract: 

 
Ecklonia radiata the dominant habitat-forming seaweed in temperate Australia has experienced high rates of mortality in the last decades. Disappearance of this kelp forest would have serious consequences for the marine ecosystem. The causes of mortality are not yet understood but we hypothesise a combination of environmental stress and viral infection. We could demonstrate that disease symptoms such as discolouration and bleaching are widespread but patchy distributed around Australia, which does not correlate simply with latitudinal variation in water temperatures. Focussing on the Kelp populations along the highly urbanised coast of Sydney we observed a highly site-specific pattern in the frequency of disease symptoms in E. radiata populations. Photosynthetic activity of discoloured thalli was significantly reduced compared to co-occurring, healthy (dark brown) thalli. Moreover, we were able to demonstrate that discoloured tissue from Ecklonia radiata from multiple sites around Sydney were infected with a viral pathogen. Inoculation experiments in the laboratory with the extracted viruses of sick tissue resulted in infection of healthy tissue of Ecklonia radiata. The frequency of putative disease morphotypes, and the relative abundance of viruses in Ecklonia radiata around Sydney appear to be higher at sites that are impacted by untreated wastewater discharge.  

Event Date: 
Wednesday, September 25, 2013 - 06:15 - 06:30
Institution: 
UWS
Title: 

Burkholderia cenocepacia mimicking host and environmental adaptation

Abstract: 

TBA

Event Date: 
Wednesday, September 25, 2013 - 07:00 - 08:00
Institution: 
Helmholtz Centre for Groundwater Ecology, Munich, Germany
Title: 

Limiting factors for anaerobic aromatic hydrocarbon degradation in contaminated aquifers and oil reservoirs

Abstract: 

 
Biography

  • Rainer Meckenstock studied biology at University of Konstanz, Germany 1985-1990. He finished with a thesis in the group of Prof. Winfried Boss on microbial sugar transport systems (molecular microbiology). He did his PhD at the Swiss Federal Institute of Technology (ETH) in Zürich, Switzerland, with a thesis on biochemistry of light-harvesting complexes of phototrophic bacteria (1990-1993) in the Institute of Molecular Biology and Biophysics with Prof. Zuber. During his post-doc at the Swiss Federal Institute of Environmental Science andTechnology (EAWAG) in the group of Dr. van der Meer in Dübendorf, Switzerland, he developed molecular methods to monitor trichlorobenzene-degrading microorganisms and their degradation activities in the environment (PCR, RT/PCR, in situ hybridisation) (1993-1995). He changed to the investigation of anaerobic degradation of aromatic hydrocarbons in the Microbial Ecology Group of Prof. Bernhard Schink, University of Konstanz, Germany, in 1996. Here, he isolated novel anaerobic BTEX and PAH-degrading organisms and studied the degradation pathways. A new method to study microbial activities in the environment with analysis of stable isotope fractionation was developed. Since 2000 he changed to the Center of Applied Geosciences at the University of Tübingen, Germany, and set up a Geomicrobiology group within the Chair of Environmental Mineralogy (Prof. Stefan Haderlein). Research topics were the anaerobic degradation of mono- and polycyclic aromatic hydrocarbons (BTEX, PAH), isotope fractionation as a means to monitor biodegradation in contaminated groundwaters, limitations of natural attentuation, and the reduction of iron minerals as electron acceptor. Since July 2003, he became the director of the Institute of Hydrology at GSF which changed its name to Institute of Groundwater Ecology at the beginning of 2004. In 2007 he was appointed as a full professor for Groundwater Ecology at the Life Science Center (WZW) of the Technical University of Munich.
Event Date: 
Wednesday, October 30, 2013 - 19:00 - 20:00
Institution: 
USyd
Title: 

How microbial community structure is shaped

Abstract: 

 
Microbes profoundly influence biological systems. Owing to their small individual size, but extremely large populations, their influence is typically an emergent property of the microbial community.  As such understanding how microbial community structure is shaped is a generic question relevant to almost all biological systems.
A major focus of my research is the interplay between diet, gut microbiota and health. Our health is the product of interplay between many different factors with arguably three of the most important being adequate nutrition, homeostatic regulation and exclusion of foreign cells. Gut functions influence all these, but occur in the immediate proximity of a huge community of microorganisms – our gut microbiome. The gut microbiome profoundly effects our health via its contribution to and influence on gut functions.
Arguably the most significant aspect of our gut microbiome is that differences in composition matter. The contribution of our microbiome to nutrition, metabolism, gut and immune functions varies from person-to-person. Thus the clinical manifestation of many diseases will be influenced by the individual’s microbiome. Secondly, environmental or lifestyle differences such as diet and hygiene may modulate microbiome composition and thus its influence on health. This gives rise to two basic opportunities for improving healthcare. These are, using the microbiome as a metric to improve diagnosis and targeting the microbiome for therapeutic intervention. We are specifically exploring forces that shape microbial community structure in mouse and human models of with a view to developing diagnostic and intervention strategies across a range of health issues. 

Event Date: 
Wednesday, October 30, 2013 - 18:00 - 18:15
Institution: 
UNSW
Title: 

NO signals for dispersing biofilms in clinical and industrial applications

Abstract: 

A story from science bench to bedside, or at least towards it What started as purely academic studies of the life cycle of bacterial biofilms, addressing the regulation of cell death events during late developmental stages, led to the discovery of a role for nitric oxide (NO) as a key regulator of biofilm dispersal. NO, which is a simple gas and universal biological signal, was found to be produced endogenously in mature biofilms, and trigger a signaling pathway involving the secondary messenger cyclic di-GMP, which in turn activates cellular effectors resulting in dispersal. Add-back of low levels (picomolar to nanomolar range) of NO was able to induce dispersal across various single species and mixed species biofilms. While the biofilm mode of growth confers a high level of resistance to control measures including antibiotics, exposure to NO greatly increases the efficacy of a range of antimicrobial treatments. Therefore the use of low, non-toxic concentrations of NO represents a promising strategy for the management of biofilms in medical and industrial contexts. Several NO-based technologies have been developed to control bacterial biofilms, including: (i) NO-generating compounds with short or long half-lives and safe or inert residues, (ii) novel materials and surface coatings which catalytically produce NO in situ, and (iii) novel compounds for the targeted delivery of NO to infectious biofilms during systemic treatments.

REPORT
Mike Manefield
JAMS this week was a real blast with an excellent presentation by Prof Rainer Meckenstock, director of the Helmholtz Institute for Groundwater Ecology. Rainer's presentation took the fed and watered JAMS audience through a tour de force of anaerobic polyaromatic hydrocarbon degradation from hard core biochemistry to field studies revealing what limits the clean up of hydrocrabons in polluted groundwater resources (the biggest freshwater resource on Earth). Tim Lachnit gave a revealing presentation on disease in seaweed (Ecklonia) driven not by bacteria but by viral infection. Ali Khameneh gave another great short talk on evolutionary responses of Burkholderia cepacia to environmental and host conditions. Ian Paulsen advertised the Synthetic Biology and Bio-engineering Workshop (see attached) - registration closes 1st Oct 2013. The audience was on fire with probing questioning of speakers giving all plenty to think about and pushing the quality of science in our community to further heights.