Compost heaps could produce biofuel

Louise Gray, Environment Correspondent
Last Updated: 6:01pm BST 09/09/2008

The humble compost heap could hold the key to providing 10 per cent of the UK's transport fuel needs, scientists have said.

The researchers from Guildford screened thousands of different wild types of bacteria, looking for one that could survive high temperatures and that liked feeding off a wide variety of plant based materials.

Compost heap: a bacteria strain was found to produce ethanol when its metabolism was slowed down
Eventually they found a suitable strain and altered its metabolism so instead of producing lactic acid as it broke down compost, it produced the useful renewable fuel ethanol.
The new strain of bacteria can break down straw and agricultural plant waste, domestic hedge clippings, garden trimmings and cardboard, wood chippings and other municipal rubbish into ethanol.
The Society for General Microbiology's Autumn meeting heard the new strain of bacteria allows ethanol to be produced much more efficiently and cheaply than in traditional yeast-based fermentation, which is based on the beer-brewing process and forms the basis for most current commercial bioethanol production.
Some seven million tons of surplus straw is available in the UK every year.

Turning it into ethanol could replace 10 per cent of the gasoline fuel used in the country.
"The bioethanol produced in our process can be blended with existing gasoline to reduce overall greenhouse gas emissions, help tackle global warming, reduce dependence upon foreign oil and help meet national and international targets for renewable energy," said Paul Milner, fermentation development manager of TMO Renewables Ltd, based in Surrey Research Park, Guildford.