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Converting wastewater into pharmaceutical-grade agar

About the pitch 

When dissolved in water, agar powder forms a gel that is uniquely suited to growing bacteria and other microbes. This humble gel has enabled lifesaving medical breakthroughs for more than a century, and even now, hospital pathologists use it every day to incubate swabs from infected patients, identify the culprit and test the effectiveness of antibiotics. Likewise, pharmacology labs develop new antibiotics by testing them against bacteria cultured on agar gel.


Without the bacteriological agar needed for this job, we would likely lose the arms race against antibiotic-resistant bacteria – a grim prospect for anyone who gets infected. It therefore makes sense to wonder where agar comes from: the answer is seaweeds, or more precisely, agar weeds! While food-grade agar weeds are farmed, the entire global supply of bacteriological agar is reliant on wild harvesting, and chronic undersupply has driven up prices and impacted vulnerable healthcare systems.


Clearly we need to learn how to farm it, yet the few previous attempts around the world have failed for often predictable reasons. I will explain how I plan to farm native Australian agar weeds by taking advantage of the wastewater stream from abalone farms right here in southern Australia. 


Meet the Speaker


Luke Barrett 

I grew up snorkelling and fishing on the south coast of Western Australia, but I got my big break in ecology when I finished high school and started working on some local conservation projects, including surveys of endangered species and reforestation of marginal farmland in biodiversity hotspots.


After a few great years in that job, I moved on to study zoology and marine biology at the University of Western Australia, and then came to the University of Melbourne in 2014 to start a PhD in marine ecology.


I graduated in 2018 and have been here ever since. I’m now a Research Fellow in Innovative Aquaculture, working across quite a few topics but with a common goal of driving more sustainable use of marine environments. I’m especially interested in the future of sustainable aquaculture (aquatic farming).


Aquaculture is growing faster than other food production sectors, with environmental impacts that depend entirely on the species being farmed and local conditions. By farming the right species in the right place with the right methods, it's possible to avoid the worst environmental costs and perhaps even provide some net environmental benefits. 

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