JAMS March 2012 Report

JAMS attendees started off the night well lubricated thanks to the free beers courtesy of some happy financial planning in our favour. The evening started with Anna Simonin from the University of Sydney discussing Neurospora crassa, a filamentous fungus that forms extensive networks by fusion of the hyphae. Anna presented some amazing live imaging of the heady flow of cytoplasm between the fungal filaments. This clever architecture is thought to influence how nutrients are distributed around the colony. To explore how these streams of nutrient traffic may be contributing to Neurospora’s substrate utilisation, the movement of stable isotope labelled amino acids was tracked within a mutant unable to fuse filaments, a mutant that had lowered fusion ability and the wild type.
Next up was Sophie Mazard from Macquarie University who was investigating who makes (and breaks) the “smell of the ocean”? Dimethyl sulphonioproprionate (DMSP) and the related dimethylsulphide (DMS) are responsible for that salty sea-dog smell and are key compounds in processes as important as cloud formation. Using stable isotope probing and high though-put sequencing, Sophie is pulling out the microbes responsible for the breakdown of DMS and DMSP produced by plants and algae in the intertidal zone of salt marshes. Working out who are the heavy-lifters in the DMS cycle is filling in gaps in our knowledge of DMS/DMSP production and degradation pathways and ultimately how this might link into the global sulphur cycle.
After the usual dearth of fine pizza, we assembled for the keynote speaker of the evening, Jeff Powell from the University of Western Sydney. Jeff introduced some intriguing ways to look at microbial community structure and how we can tease apart their contributions to biogeochemical cycling. Microbial ecologists know that trying to link communities to specific functions can be a complicated business. One approach is to try and correlate differences in community composition to differences in environmental parameters, while the other is to conduct manipulations of the community and watch for functional changes. Both approaches have their advantages and shortcoming in unravelling the relative contributions of microbes to ecosystem functions. To help do so, Jeff is experimenting with multimodel inference and model selection to estimate the how much is really being driven by microbial diversity and how we can make truly predictive models of ecosystems.
Don’t forget to come along to JAMS in April for more free booze and for the first time on a Tuesday night at the Museum.