When most people think of bacteria, chances are they’re thinking of disease. But certain bacteria can be helpful as La Trobe University’s Dr Ashley Franks has discovered. Some bacteria are so useful they can be employed to solve a whole range of environmental issues, like creating more fertile land for farmers by eliminating pollution and waste and thereby improving the health of plants. There are even electric bacteria that have super powers. Electric bacteria are possessed with the ability to eat and breathe electricity, producing small-scale ‘batteries’ that could assist remote communities without renewable energy sources. Dr Franks’ research also shines a light on the role bacteria play in keeping the human body fit and healthy.
Welcome, then, to the electrifying world of helpful bacteria. Your guide: Dr Ashley Franks.
Ashley, is it really true there are bacteria that can eat and breathe electricity?
Everything we run on, anything we do, is basically electrons and electricity. When people eat food and then breathe oxygen, it’s all about transferring electrons from that food through chemical reactions. These bacteria take a short cut. Rather than eating the food and bringing it back into themselves, they can take the electrons directly; rather than breathing oxygen, they can give electrons out directly. It’s like breathing by touching a wall instead.
Bacteria in the environment have probably already worked out how to do most things that we’re still trying to do ourselves. They know the right environmental drivers – how to feed each other electricity, how to fix nitrogen and get sunlight, how to produce organics to make fuels. If we understand these processes, then we can apply them and use them on a worldwide scale.
How do you collect the bacteria in order to put it to work?
If you put an electrode in the ground, you can collect electrons and give the bacteria something to breathe. But as well as doing that you can feed the bacteria electrons; it’s all about which way the energy’s going. For them to eat it, they need to be touching it. So if your food is a contaminant spill, the bacteria can eat it but normally they don’t have enough to breathe, so you can put the electrode in and they munch it all up.
One per cent of bacteria are dangerous. Worrying about that kind of bacteria is like taking a flamethrower to your back garden in case you’ve got weeds. Everybody thinks of the bad stuff but they always forget the good stuff out there.
It’s like a secret world. How did you discover it?
I’ve always been interested in old processes. These electron transfers probably developed before the Earth had oxygen; this is the way bacteria used to breathe without oxygen. I was always interested in that, but then you realise you can control that, you can speed it up, you can change it. And then you think about the applications.
Can you harness the energy of electric bacteria as an alternate fuel source?
They will produce electricity, but only a small amount continuously over a long time. If you can capture sunlight somewhere without power, then you feed that to the bacteria and get them to make something like butanol and then send that back to where you need it. It may only be able to charge a battery over a day to give an hour of light, but if that’s an hour of light you don’t usually have then it’s worth it.
Apparently, it’s difficult to harness the power of bacteria due to energy loss. Can you redesign them?
We have a synthetic biology project to reduce the bacterial DNA down into a computer program. If you understand the processes, you’ll be able to build bacteria to do what you want.
Bacteria have evolved to put energy into their survival, but we can actually change that so that rather than grow, they put out energy in a different way. Normally, if we want the bacteria to output some form of product or chemical, it’s not a favourable equation as the energy doesn’t match up. But we can use electricity to add energy or take energy away, adding the balance as required.
I always tell my students we’re basically a tube of bacteria. Basically, we have a mouth and it comes out the other end. Bacteria can control our mood, and they force us to go and find food – to feel hungry, happy and sad. They can pass things through your gut and our brains communicate with them. They are very much a part of us.
How can bacteria help the human body?
People with autism spectrum disorder often have chronic gut problems. We’re studying mice that have a signaling pathway in the brain, which causes differences in the bacteria in the gastrointestinal tract. Those bacteria can then influence behaviour. We’re trying to work out these mechanisms, because if you have imbalances in your gastrointestinal tract, it can be associated with depression or anxiety – a whole range of different things.
You’ve won awards and worked at institutions worldwide. What draws you to La Trobe?
One thing I really like about La Trobe is its focus on the environment. Other Australian universities have lost that, but we’ve still got agriculture, plant and soil sciences, ecology, evolution. There’s a lot of us at La Trobe with very different skill sets, and we work on common problems. The other thing I like about La Trobe is that it supports science Research Focus Areas.
It’s a university that really supports people to do good research.
Dr Ashley Franks is Reader/Associate Professor in the College of Science, Health and Engineering at La Trobe University.
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