Environmental Issue

Event Date: 
Wednesday, July 29, 2015 - 18:15 - 18:30
Institution: 
Australian Institute of Marine Sciences
Title: 

Coral Reefs Go Viral: Unveiling the viruses associated with corals in a changing climate.

Abstract: 

Viruses are the most common biological agents in the global oceans, with numbers typically averaging ten billion per litre. The ability of viruses to infect all organisms indicates they most likely play a central role in marine ecosystems and have important consequences for the entire marine food web. Marine viruses influence many biogeochemical and ecological processes, including energy and nutrient cycling, host distribution and abundance, and horizontal gene transfer events. Research into viruses associated with coral reefs is a newly emerging field. Corals form an obligate symbiotic relationship with the dinoflagellate genus Symbiodinium, upon which the coral relies heavily for nutrition and calcification. Disruption of this symbiosis can lead to loss of the symbiotic algae from their host, resulting in coral bleaching and, if the symbiosis cannot re-establish, death of the coral colony. While a number of factors, including elevated reactive oxygen species production by Symbiodinium have been linked to coral bleaching, viral infection has not been methodically examined as a possible cause. Viruses that potentially target the algal symbiont, Symbiodinium sp., have been reported previously; therefore, we examined whether Symbiodinium in culture is host to a virus that switches to a lytic infection under stress, such as UV exposure or elevated temperature. Analysis of algal cultures, using techniques including flow cytometry and transmission electron microscopy, revealed prevalent viral activity, regardless of experimental conditions. This talk will present recent results and results allow for the development of molecular diagnostic probes for rapid detection of viruses in field samples, and will help monitor and assess the role of viruses in coral bleaching and holobiont functioning.

Event Date: 
Wednesday, February 25, 2015 - 15:00 - 15:30
Institution: 
University of East Anglia
Title: 

Bacterial metabolism of isoprene

Abstract: 

Isoprene (methyl isobutene), is a climate-active volatile organic compound that is released into the atmosphere in similar quantities to that of methane, making it one of the most abundant trace volatiles. Large amounts of isoprene are produced by trees but also substantial amounts are released by microorganisms. The consequences on climate are complex. Isoprene can indirectly act as a global warming gas but in the marine environment it is also thought to promote aerosol formation, thus promoting cooling through increased cloud formation. We have been studying bacteria that grow on isoprene. These aerobic bacteria appear to be widespread in the terrestrial and marine environment. Rhodococcus AD45, our model organism, oxidizes isoprene using a soluble diiron centre monooxygenase which is similar to soluble methane monooxygenase. The physiology, biochemistry and molecular biology of Rhodococcus AD45 will be described, together with genome analysis, transcriptome analysis and regulatory mechanisms of isoprene degradation by bacteria. The ecology of isoprene degraders in both the terrestrial and marine environment will be described, together with DNA-Stable Isotope Probing experiments which have enabled us to identify active isoprene degraders in the environment.

Event Date: 
Wednesday, March 26, 2014 - 19:00 - 20:00
Institution: 
UTS, Australia
Title: 

Feeling Hot Hot Hot: Insights on thermal regulation of microbial carbon fixation and metabolism in a warming ocean

Abstract: 

Ocean warming is expected to affect marine microbial phototrophs directly by influencing their metabolism and capacity for photosynthesis as well as indirectly through altering the supply of resources needed for growth. In turn, changes in phototrophic community composition, biomass and size structure are expected to have cascading impacts on export production, food web dynamics and fisheries yields, as well as the biogeochemical cycling of carbon and other elements. As a result, temperature is a critical parameter in coupled climate-ocean models because it influences not only the magnitude, but also the direction of future ocean productivity.
 
This seminar presents data from several recent oceanographic voyages to suggest that the statistically significant relationships found between temperature and carbon fixation of contemporary ocean microbes is confounded by the availability of co-varying light and nutrient resources, and challenges the notion that satellite-derived sea surface temperature is a suitable proxy for tracking changes in upper ocean biogeochemical function. It will also present laboratory data which demonstrates that thermal selection of photosynthetic microbes (over >100 generations) results in phenotypic trait evolution and shifts in photosynthesis:respiration. Collectively, these data show non-linearity in metabolism of photosynthetic microbes in a warming ocean, pointing to increased variability of responses and potentially less predictability in models.

Event Date: 
Wednesday, October 31, 2012 - 06:00 - 06:15
Institution: 
UTS
Title: 

Sulfur scent for a harmful algae killer

Abstract: 

 
Marine harmful algal blooms (HABs) are dense ephemeral proliferations typically of dinoflagellates, cyanobacteria or diatoms. These HABs can cause illness and death in humans and marine life, or ecosystem alterations affecting food provision and recreational activities. Despite being recognised as a major environmental challenge, little is known about what makes HABs thrive and vanish. For dinoflagellates, which account for 75% of HAB-forming phytoplankton species, bottom-up factors (including: eutrophication, climate change and species dispersal) are common triggers, yet the causes of bloom termination remain obscure.
Parasitoids have been identified as a major cause of termination of coastal harmful algal blooms, but the mechanisms and strategies they have evolved to efficiently infect ephemeral blooms are largely unknown. This study investigated the potential cues for parasite infection by the generalist dinoflagellate parasitoid Parvilucifera sinerae (Perkinsozoa, Alveolata). It showed that P. sinerae was activated from dormancy by Alexandrium minutum cells. Further investigation identified the algal metabolite dimethylsulphide (DMS) as the density-dependent chemical cue for the presence of potential host cells. The presence of DMS allowed the parasitoid to alternate between a sporangium-hosted dormant state and a chemically activated, free-living virulent state. DMS-rich exudates from infection-resistant dinoflagellate species also induced parasitoid activation, which can be interpreted as an example of a co-evolutionary arms race between parasitoid and host. These results further expand the involvement of dimethylated sulphur compounds in marine chemical ecology, where they have been described as foraging cues and chemoattractants for mammals, birds, fish, invertebrates and plankton microbes.

Sydney may have failed to deliver some sunshine on the last day of a slightly extended summer, but this didn’t dampen the spirits of Sydney’s microbiology community who turned out in numbers for the Inaugural JAMS Anniversary half-day meeting at the Australian Museum. This special meeting celebrated the first birthday of JAMS, an ASM special interest group that aims to bring together research microbiologists, post-docs and PhD students working in non-clinical research from all institutes.

Special thanks must go to the sponsors of the meeting: POCD scientific; Becton, Dickinson and Company; Macquarie University; The University of Sydney; The University of NSW; The University of Technology, Sydney, and; The University of Western Sydney. Another special thank you must also go to Federico Lauro (UNSW) and other members of the JAMS steering committee for organising the anniversary meeting and for their continued commitment to JAMS. The steering committee would also like to thank the Australian Museum who kindly provided the venue for our regular meetings and who hosted this special event.

Event Date: 
Wednesday, February 29, 2012 - 16:15 - 16:45
Institution: 
University of Saskatchewan, Canada
Title: 

The World’s Tipping Point: How genes, enzymes, microbes and plants regulate greenhouse gas release from Arctic Soils.

Abstract: 

Arctic soils contain as much carbon as the tropical rainforest. This carbon sequestered in permafrost is in danger of being released to the atmosphere. In this talk, I will discuss what regulates greenhouse gas release from Arctic soils and how, surprisingly, carbon containing greenhouse gases are not the key greenhouse gasses determining how warming Arctic soils influence our global climate. Drawing on the longest running climate change experiment in the Arctic, I will discuss how genes, enzymes, and microbial communities interact with one-another and with soil/plant properties to regulate greenhouse gas release at the field and continental scale. The role and importance of scale in determining biological interactions will be examined and what the implications of such scales are on our climate’s future.

Event Date: 
Wednesday, February 29, 2012 - 18:30 - 19:00
Institution: 
CSIRO Livestock Industries, St. Lucia, Australia
Title: 

Differences downunder: macropodids, methane and metagenomics.

Abstract: 

The agricultural sector accounts for a large amount of Australia’s greenhouse gas emissions, and strategies that reduce the production and (or) release of methane from ruminant livestock has resurfaced as a viable research topic. While there has been a relatively intense focus on better understanding how rumen microbiology, nutrition and (or) animal genetics might be targeted and productively altered to reduce these emissions; less attention has been directed towards the comparative study of those native Australian herbivores thought to produce small amounts of methane during feed digestion. These animals include the Australian macropodids (kangaroos and wallabies), which have evolved to retain a foregut microbiota that effectively converts plant biomass into nutrients for the host animal; and appears to do so with much less methane emitted. Our research group in Brisbane has used metagenomics approaches with a view to characterize the foregut microbiota of the Tammar wallaby (Macropus eugenii). There is a reduced number of methanogenic archaea resident in the macropodid foregut compared to ruminants, but the species present appear to have some unique attributes relative to their counterparts from other environments. We have also used a combination of metagenomic data and cultivation-based methods to identify and isolate several “new” bacteria that support feed digestion and fermentation schemes consistent with a low methane emitting phenotype. The structure-function relationships inherent to these interesting gut microbiomes warrant further investigation.

Event Date: 
Wednesday, February 29, 2012 - 14:30 - 21:00

You are invited to our inaugural anniversary half-day meeting at the Australian Museum, set for February 29th. Please sign-up to this event if you wish to attend or email us if need be.

Registration costs have been reduced to $35 for students and $75 for everyone else, thanks to the generous sponsorships of POCD Scientific, BD, The School of Molecular Bioscience (U. Sydney), The School of Biotechnology and Biomolecular Sciences (UNSW), The School of Medicine (UWS), The Biomolecular Frontiers Research Centre (Macquarie U.), The Environmental Microbiology Initiative (UNSW), The C3 and I3 Institutes (UTS).

There is an expanded schedule with some great speakers from out of town and a poster session for PhD students. As an incentive for students to present their work, the best poster will be awarded with the inaugural EMI Best Poster Award.

If you intend to present your work, please provide a poster title during registration.

The schedule of the meeting is as follows:

2.30 - 3.00pm Poster setup.
3.00 - 3.15pm Welcomes, introductions and acknowledgements.

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