Monday, 3 June, 2002, 15:25 GMT 16:25 UK

Kangaroos offer clue to global warming

Kangaroos stomachs contain different bacteria

By Richard Black
BBC science correspondent

Scientists in Australia are investigating whether kangaroos could help combat global warming.

Australia's sheep and cattle produce huge amounts of methane, an important greenhouse gas - but kangaroos do not.

Researchers believe it might be possible to use bacteria found in the stomachs of kangaroos to reduce methane output from cows and sheep.

Methane emissions from farm animals account for about 15% of Australia's greenhouse gas production.

Yet kangaroos, feeding on the same sorts of grass, produce no methane at all.

Mystery bacteria

It is all down to the bacteria in their stomachs which help process the food they eat.

Farm animals make 15% of Australia's greenhouse gases

The stomach is basically a big fermentation tank, with lots of hydrogen in the frothy mix; sheep and cattle bacteria turn that hydrogen into methane, whereas kangaroo bacteria do something else with it.

Precisely what that something else is is still something of a mystery, but researchers in Queensland have isolated about 40 types of bacteria from kangaroo stomachs and are finding out how they work.

Then they can try putting them inside cattle and sheep, to replace the methane-producing bacteria.

As well as being more climate-friendly, the kangaroo bacteria could be good news for farmers too by raising yields of wool, milk and meat.

Kangaroo bacteria have evolved over millions of years to process Australian grasses, and so should be more efficient at it than sheep and cattle bacteria, which arrived from Europe during the last two centuries.