Biofuels study gives clue to forest ecosystems

The genome of a dry rot fungus has revealed how it can cause severe damage to buildings. The findings could help in the development of biofuels and may explain how conifer forests evolved.

In 2007 the US Department of Energy’s Joint Genome Institute sequenced Serpula lacrymans in order to see if the way it breaks down cellulose in wood could be harnessed for biofuel production. An international team analysing the genome have found the enzyme mechanisms that could explain the aggressive decay caused by this form of dry rot. These may help develop new pretreaments for biofuel production from agricultural wastes.

A report of the research is published in this week’s Science.

‘Alongside looking at the relevance for biofuels we also compared the genome of this fungus to the genomes of ten forest fungi. What we discovered is that the development by fungi of more sophisticated ways of breaking down wood seems to have gone hand-in-hand with the evolution of conifer forests,’ said Dr Sarah Watkinson of Oxford University’s Department of Plant Sciences, who led the team with Dan Eastwood of the University of Swansea.

Dr Watkinson said: ‘Brown rot fungi like the dry rot fungus leave behind carbon-rich lignin, because they have evolved the ability to extract digestible cellulose and leave the part of the wood they can't use as reddish-brown waste which takes decades to decompose. These fungi give northern conifer forests from the Rockies to Siberia their special carbon-rich, nutrient-poor soils, and this might even be the reason for the reddish brown colour of squirrels and pine martens, camouflaged against the residues from fungal wood decay.’

Conifer forests are a major terrestrial carbon sink with the soil residues of brown dry rot fungi contributing up to 30% of the carbon found in conifer forest soils.

A report of the research, entitled ‘The plant cell wall decomposing machinery underlies the functional diversity of forest fungi’, is published in this week’s Science.

Source: Oxford University