Washington: Scientists have mapped metabolism of a bacteria called Nostoc, which fixes nitrogen and releases hydrogen, possibly bringing sustainable fuel from microbes one step closer to reality.

Like all living creatures, bacteria sustain themselves through metabolism, a huge sequence of chemical reactions that transform nutrients into energy and waste.

Fixing nitrogen is an energy intensive process and it wasn't clear how the bacterium produces the energy it needs in order to survive. But the process has been mapped with the help of a new computer system.

Until now, scientists have had difficulties identifying bacteria metabolic pathways. The bacterial metabolism is a huge network of chemical reactions, and even the most sophisticated techniques can only measure a small fraction of its activity.

Guido Sanguinetti, of Sheffield University's department of computer science, who led the study, said: "The research uncovered a previously unknown link between the energy machinery of the Nostoc bacterium and its core nitrogen metabolism."

"Further investigation of this pathway might lead to understanding and improvement of the hydrogen production mechanism of these bacteria. It will certainly be some time before a pool of bacteria powers your car, but this research is yet another small step towards sustainable fuels."

"The next step for us will be further investigation into hydrogen production, as well as constructing more mathematical models capable of integrating various sources of biological data," he added.

The research has been published in Bioinformatics. IANS