JAMS June 2011 meeting report by David Wilkins

How many microbiologists does it take to change a light bulb? None, as it turns out - the dozens of attendees at June's Joint Academic Microbiology Seminars (JAMS) at the Australian Museum waited patiently through a short blackout for drinks, snacks, and three servings of fresh scientific discussion.

Matthew Lee of UNSW's Centre for Marine Bio-Innovation gave the first 15 minute talk, presenting his study of chloroform degradation in contaminated soils. Matt explained that chloroform has long been a bugbear of the bioremediation community, stubbornly resisting degradation by dehalogenating bacteria. Worse, its presence can inhibit the dechlorination of other organochlorines, making the identification of chloroform degraders an important key to remediating heavily polluted sites. Matt and colleagues have identified bacteria from the genus Dehalobacter which fit this role, dehalorespiring chloroform to dichloromethane then fermenting it to formate and acetate. Their cultures are now being used in field trials at contaminated sites.

Adam Jones from San Diego's Scripps Institution of Oceanography took the stage for the second short presentation. The marine cyanobacterium Lyngbya majuscula is big, purple, and bursting with bioactive secondary metabolites, but hard to study due to a slow growth rate and the difficulty of obtaining axenic cultures. Adam and his colleagues at Scripps have improved in vitro analyses of Lyngbya metabolites using mass spectrometry and stable isotope feeding, and used these techniques to identify differential expression of the neurotoxins jamaicamide A and B under light and dark conditions. They have also developed an heterologous expression platform in Streptomyces coeilcolor, paving the way for further studies on this promising source of novel pharmacological and biotechnological compounds.

The meeting broke for pizza and drinks, generously sponsored by the ASM, before USyd medical entomologist Cameron Webb rounded off the evening with a 45 minute talk. He took the audience on a tour of the mosquitoes of Australia and the diseases they carry. The fascinating and entertaining revelations ranged from the distribution of Ross River fever (not just a disease of the far north), to the best way to catch a mosquito (all you need is a billy can and a block of dry ice), to his studies on the effectiveness of insect repellents (nobody in the audience will be using “natural” repellents again). Cameron's talk emphasised how factors such as climate, land use and even human behaviour can have complex and unpredictable effects on the distribution of mosquito-borne diseases.