THEY sound like unlikely warriors against greenhouse gases, but bacteria found in kangaroos’ stomachs could be just that. Feeding the bugs to sheep and cattle could drastically cut emissions of the potent greenhouse gas methane.
Cud-chewing animals have a lot to answer for. A sheep typically burps out 25 litres of methane a day, while cows can expel a staggering 280 litres in the same period. Together, they account for around 14 per cent of the greenhouse gas emissions from Australia and 50 per cent from New Zealand. Methane is a far more potent greenhouse gas than carbon dioxide.
Like cows and sheep, kangaroos produce hydrogen when they digest grass. But instead of converting it into methane, bacteria in the stomachs of kangaroos produce a substance called acetate which the roos can use as a further energy source.
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Athol Klieve of the Animal Research Institute at Australia’s Department of Primary Industries (DPI) in Queensland believes that if the species of bacteria responsible for the kangaroos’ trick can be identified and collected, they could be fed to cattle and sheep to trim their emissions. “This is highly feasible, because the actual digestive process is the same,” he says. “It’s the microbes that have evolved differently in kangaroos.”
Klieve is now sorting through the multitudes of bacterial species in kangaroos’ stomachs to find the ones that produce acetates. “We’ve isolated 40 of them so far, and 20 are completely new species,” he says. It may take two years to isolate all the necessary bacteria. Klieve and his team will then turn their attention to finding the best way to introduce the bacteria into stomachs of sheep and cattle.
“If we can get a breakthrough here, it’ll be great news for the environment,” says DPI minister Henry Palaszczuk. “It will mean a reduction in the 60 million tonnes of gas emissions that come from our cows and our sheep each year.”