Mutant fungus doubles biofuel enzyme production

Scientists have mutated variants of a certain fungus to double the production of endoxylanase enzymes, which are used in bioethanol production.

The discovery comes as part of a hunt for more cost effective methods to convert biomass into ethanol, particularly in the form of easier production of enzymes used to fire the conversion process.

These enzymatic catalysts are commonly produced by using fungi, but they can be difficult to handle and the production process is often slow.

To address this problem, researchers have taken a common fungus called Aspergillus niger and through careful exposure to gamma radiation mutated it into a form that produces enzymes more effectively.

The fungus produces the enzyme β-1,4-endoxylanase, which is able to break down hemicellulose, complex carbohydrates found in plant material.

The mutated fungus strain produces this enzyme at a doubled rate when compared to the naturally occurring form, and the enzymes are produced in smaller and more concentrated pellets, which are easier to handle.

Further research is now underway to see how the mutated fungus can be used on an industrial scale.

The mutations were produced by Jin Chuan Wu of the A*STAR Institute of Chemical and Engineering Sciences.

The findings have been published in the Biochemical Engineering Journal, in a paper headed ‘Improved endoxylanase production and colony morphology of Aspergillus niger DSM 26641 by γ-ray induced mutagenesis’.