Hungry fungus shows potential for green fuel


Washington : A spidery fungus feeding ravenously on military uniforms and tents holds the key to improved biofuel production, according to a study.

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The finding could enable more efficient and cheaper conversion of maize, switch grass and even cellulose-based municipal waste into ethanol. Ethanol from waste products is a more carbon neutral alternative to petrol.

The fungus T. reesei rose to notoriety during World War II when military leaders found it feeding on clothing and tents in the South Pacific and rendering them useless.

Named after Elwyn T. Reese, who isolated the hungry fungus, T. reesei was later identified as a source of industrial enzymes and a role model for the conversion of cellulose and hemicellulose – plant fibres – into simple sugars.

The organism uses enzymes it creates to break down human-indigestible fibres of plants into the simplest form of sugar, known as a monosaccharide. The fungus then digests the sugars as food.

Researchers decoded the genetic sequence of T. reesei in an attempt to discover why the deep green fungus was so good at digesting plant cells, reports Sciencedaily.

“We were aware of T. reesei’s reputation as producer of massive quantities of degrading enzymes, however we were surprised by how few enzyme types it produces, which suggested to us that its protein secretion system is exceptionally efficient,” said Los Alamos bioscientist Diego Martinez, of University of New Mexico and the study’s co-author.

Researchers believe that T. reesei’s genome includes “clusters” of enzyme-producing genes, a strategy that may account for the organism’s efficiency at breaking down cellulose.

Industrially, T. reesei could be employed to secrete enzymes that can be purified and added into an aqueous mixture of cellulose pulp and other materials to produce sugar. The sugar can then be fermented by yeast to produce ethanol.

“The sequencing of the Trichoderma reesei genome is a major step towards using renewable feedstocks for the production of fuels and chemicals,” said Joel Cherry, director of research activities in second-generation biofuels for Novozymes, a collaborating institution in the study.

The paper was published on Monday in Nature Biotechnology.