September 2015

Event Date: 
Thursday, October 8, 2015 - 15:00 - 19:00

 

JAMS will be presenting a seminar series at the Westmead Millennium Institute, held 3-7pm Thrusday October 8th.

Registration is free, please RVSP.
Afternoon tea and dinner with drinks will be provided.

Seminar Speakers:

Dr Cameron Webb – Plenary

Mosquito‐borne disease in Australia: emerging threats and novel solutions

Prof Shari Forbes

Profiling breath samples for detection of volatile bacterial ‘fingerprints’ in lung infections

Dr Carola Venturini

Gut microbial ecology: the side‐effects of antibiotic treatment

Dr Gurjeet Kohli

Hunt for toxin biosynthesis genes in dinoflagellates

Dr Matthew O’Sullivan

Managing healthcare workers with suspected Ebola in Sierra Leone

Connie Ha

The guts of lifestyle disease management: targeting host‐microbiome interactions for optimal intervention

Event Date: 
Wednesday, September 30, 2015 - 19:00 - 19:45
Institution: 
University of Southern California
Title: 

Microbial evolutionary surprises in the future ocean:  Long-term adaptation of marine nitrogen-fixing cyanobacteria to high CO2

Abstract: 

The globally-distributed marine cyanobacterium Trichodesmium plays a key role in ocean biogeochemical cycles, as it is a major source of newly fixed atmospheric nitrogen to marine food webs.  Trichodesmium N2 fixation rates have been shown to increase under expected future high carbon dioxide (CO2) levels in short-term studies due to physiological plasticity, but its long-term adaptive responses to ongoing anthropogenic CO2 increases are unknown. My lab has been carrying out a nearly decade-long experimental evolution study with Trichodesmium growing under selection by projected future elevated CO2 levels.  Unexpectedly, selection under high CO2 results in large increases in nitrogen fixation and growth rates that appear to be irreversible, even after adapted cell lines are moved back to lower present day CO2 levels for hundreds of generations. This represents an unprecedented microbial evolutionary response, as reproductive fitness increases acquired in the selection environment are maintained even after returning to the ancestral environment. These constitutive rate increases are accompanied by irreversible shifts in diel nitrogen fixation patterns, up-regulation of cellular energetic pathways, elevated expression of non-coding intergenic DNA, and increased activity of a potentially regulatory DNA methyltransferase enzyme. Ongoing work in my lab is examining the consequences of multiple nutrient limitation interactions (iron and phosphorus) for the physiology, biochemistry and genetics of Trichodesmium adapted to growing in a more nutrient-limited, acidified future ocean environment.  
 

Event Date: 
Wednesday, September 30, 2015 - 18:00 - 18:15
Institution: 
Macquarie University
Title: 

Aquifer microbial community assembly: do neutral processes dominate?

Abstract: 

Community assembly processes can be condensed into four categories: dispersal, selection, drift and speciation. We tested aquifer communities (of Archaea, Bacteria, Fungi, and Eukarya generally) for evidence that dispersal limitation and environmental selection play a role in determining community biodiversity and composition. We found only weak evidence for these processes at a regional scale of up to 250 km and spanning several significant dispersal barriers. I discuss the possibility that neutral (i.e. non-deterministic, non-selective) processes dominate in groundwater ecosystems, and the spatial scaling of these processes.

 

Event Date: 
Wednesday, September 30, 2015 - 18:15 - 18:30
Institution: 
UTS
Title: 

Divergence in temperature stress management between coastal and East Australian current (EAC) phytoplankton populations.

Abstract: 

In June 2015, 27 scientists took part in a 3 week ocean voyage aboard the brand new Australian research vessel, the RV Investigator. The main objective of the expedition was to study sub-mesoscale processes - billows and eddies - along the productive shelf influenced by the East Australian Current. Dr Olivier Laczka is presenting the results obtained for one of the multiple projects conducted during this voyage. Microbial communities from the EAC and a coastal site (north of Smokey Cape) were incubated along a temperature gradient (spanning 32 to 15.5 °C) to examine their capacity to deal with departures from in situ temperature (~22 °C). Intracellular stress within picoeukaryote populations was examined using a fluorescent stain targeting Reactive Oxygen Species (ROS). Stained samples were examined with a flow cytometer (excitation wavelength 488 nm). The goal of this study was to assess whether EAC microbial communities are more thermally tolerant than coastal microbial communities and determine whether general oxidative stress patterns could be used as a signature of water mass origins.