Country Life: Capturing greenhouse gases for farm feed

Bubbling away in a Rotorua lab is a substance that could help feed the world's growing population and lower carbon emissions.

That's the hope of scientists and researchers working on a plan to turn the sticky goo produced by some tough little bugs into a nutritious animal feed.

I donned a lab coat to find out more from Andy Blair of the geothermal consultancy Upflow, Scion's microbial biotech team lead Christophe Collet and the research agency's bioproducts expert Alec Foster.

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The technology, which is projected to generate $500 million annually by 2045, uses bacteria and algae which feed on carbon dioxide and methane, waste gases from geothermal power, to produce a protein-rich biomass.

The microbes, harvested from geothermal sites, are used to living in an extreme environment and their qualities are useful for biotech, Blair explained.

"We're looking for solutions in the world using those bodily adaptions in the way that they function and that led to the idea of turning the protein-rich biomass produced by the greenhouse gas-eating microbes into something useful and nutritious, like stock feed. Turning something that's a problem into something of value."

We stop in the corridor of Scion's Orman Wing to ruminate on the possibilities for the substance produced by the microbes churning around in small bioreactors and feeding on gas piped into the system.

This is a much smaller scale of the next stage in the $5 million project - to build a pilot plant at a geothermal site in Taupō.

The biomass, we decide, looks a bit like pink icing, jelly or marmite depending on whether it's a bacteria or algae and what gas it's eating. So how would it work on farm?

The team are working on the idea of pelleted stock feed but will be listening closely to what the market wants.

A commercial competitively priced stockfeed is five to 10 years away, according to Foster.

"[The microbes] have got a spectrum of amino acids, and those amino acids are essential. We tend to think of it being maybe a bit unusual to be eating bacteria, but, actually, animals do it every day."

He says the process doesn't rely on genetic engineering or gene editing, simply the natural microbes eating the gas.

Part of the project, funded 50-50 by the Ministry for Primary Industries and a central North Island Māori Trust - Tauhara North No. 2 - will be to analyse how different animals respond to the feed, which has already been tested for toxicity and palatability.

Only mice trials have been conducted so far.

"The weights were comparable or better with our feed, so that the mice were happy to eat it, and they bulked up just as they would with normal feed," Foster said.

"The biggest challenge is scaling, making it economical at scale and that's our big, big push."

Part of the impetus for the project was learning that New Zealand imported tons of palm kernel extract (PKE) from palm oil plantations in Asia as supplementary feed for stock, Blair said.

"That was quite horrifying for us to hear that New Zealand, that prides ourselves as a clean, green production country, and doing smart, making ethical decisions, was contributing to such large scale deforestation and other activities, and there's so much carbon loaded in the transport of that to New Zealand."

Plugging into New Zealand's geothermal power stations is only the start and the team's ultimate goal was to deploy the technology overseas, she said.

"It's about offering a decarbonized, meaningful commercial operation that is sustainable and good for planet and people."

"It's really New Zealand positioning itself at the forefront of food and feed," Foster added.

Learn more:

• Find out more about Scion here