Australasian Science: Australia's authority on science since 1938

How to Feed and Fuel the World

By Stephen Luntz

Dr Kirsten Heimann is using her intimate knowledge of algae to develop them as viable biofuels and animal feeds.

When first invited to work on microalgae, Dr Kirsten Heimann of James Cook University responded “under no circumstances”. Her change of mind has led to a research project that could be a game-changer in the battle against both global warming and global hunger.

Heimann is feeding microalgae a combination of wastewater and carbon dioxide, and turning the resulting growth into a mix of animal feed and biofuel, with some human food on the side. By the end of this year a 1 ha prototype will be operating using flue gas from the Tarong power station near Kingaroy in Queensland.

The idea of using algae to produce biofuel is not new. The oil shock of the early 1970s promoted considerable investment in mimicking the natural process of oil formation. However, Heimann says: “The interest then was purely about oil, and when oil prices went down the money was pulled out. Now we are living in a carbon-constrained world and may have reached peak oil, or will reach it by 2030.

“The world population is rising and so is energy demand. We need to find ways to address this.” Unlike other sources of biofuel, algae don’t compete with food crops or biodiversity for land. Heimann’s species can be grown in tanks on non-arable land around power stations.

Despite their potential, algae have floundered as a biofuel because the processes were too expensive. The first “bottleneck” Heimann had to overcome was finding the right strain of algae. “After 20 years of research I know these organisms inside-out, and I know what they like,” she says.

Heimann insisted on using only local Queensland strains to eliminate contamination concerns, and eschewed genetic modification. Different strains produce different products, with some rich in omega-3 fatty acids and protein that may prove useful as a cheap, healthy human food. Queensland Premier Anna Bligh described one marine strain as tasting like “green Vegemite” while Heimann says freshwater varieties are “bland like tofu, so you need to spice them up”.

Strains better suited to other sites produce more biofuel, as well as food products appreciated by cows.

Drastically cheaper cultivation systems removed another bottleneck, while a third came when she borrowed methods from wastewater technologies to concentrate the products at the end.

Other research teams bubbled carbon dioxide through their tanks, allowing plenty to escape. Heimann dissolves the gas in water and regulates delivery to match the algae’s consumption. The only carbon dioxide that should escape a sufficiently large treatment plant is CO2 produced at night, since the algae need light to grow. Heimann says overnight storage of the gas would be difficult, but hopes it may become possible to provide light around the clock to keep the microalgae growing.

Such a significant project uses up much of her time, but Heimann is also studying ciguatera, the product of a far less friendly form of microalgae. Ciguatera poisoning is so painful Heimann says people have described “wanting to rip their own eyes out”. Not only can the pain last 6 months after eating fish that have bioaccumulated a critical dose, but relapses can be triggered by eating unpoisoned sea food or even unrelated foods such as peanuts.

The poison is resistant to cooking or freezing, and no test exists. The responsible algae thrive in warmer conditions and where macroalgae replace coral reefs, conditions whose abundance is growing. Many Queensland cases are already misdiagnosed.

A cell biologist by background, Heimann still conducts research on animal cells, seeking antibacterial and anticancer drugs.

“I was always interested in nature,” Heimann says. “As soon as I could walk my parents couldn’t find me because I was playing in ponds, observing nature. I was fascinated because nature was so unforgiving. Most organisms if they make a mistake don’t get a chance to learn. I wanted to know why that was, how organisms interact and what happens when they don’t follow the game plan. My mother was not impressed because I used her crystal ball as a salamander-capturing device.”

This interest led to a Bachelor’s degree in her native Germany and a PhD from Cologne. A scholarship that had to be taken outside Europe led to postdoctoral positions at Melbourne and Monash universities, and she spent time in Louisiana before securing a position as a lecturer at James Cook University.

So why did she initially resist the species that would become her passion? “We had a terrible lecturer who made them sound so boring I said I could never work on something so uninteresting.” However, one of her doctoral supervisors (for a thesis studying calcium uptake in spinach) persuaded her to take a look at his lab. Heimann realised: “This is state-of-the-art cell biology. They allow you to ask really interesting questions.”