Biofuels turn to fungus

One of the avenues being explored to bring down the cost of the production of 2^nd-generation bioethanol is improving the performance of the filamentous fungus Trichoderma reesei strains by genetic engineering.

Frédéric Monot Applied Chemistry and Physical Chemistry Division frederic.monot@ifpen.fr	Antoine Margeot Applied Chemistry and Physical Chemistry Division antoine.margeot@ifpen.fr

The production of 2^nd-generation bioethanol requires the action of enzymes, generally derived from the filamentous fungus Trichoderma reesei. These enzymes are obtained by cultivating the fungus in a fermenter. However, the cost of this process is still too high. One of the avenues being explored to bring down the cost is improving the performance of Trichoderma reesei strains by genetic engineering.

The challenge for molecular genetic engineers is to identify which of the several thousand genes need to be modified to improve the strain. To do this, they use genomics and systems biology techniques, enabling collection of all the cellular information: DNA sequence, expression of genes in a given culture condition, etc. In this way, they aim to create a predictive model of micro-organism behavior.

Working closely with the Ecole Normale Supérieure in Paris and several laboratories in Europe and the USA, IFPEN researchers have deciphered the genome of a complete lineage of Trichoderma reesei strains. For the first time, they have obtained an exhaustive list of the mutations that affect these strains. This work is currently being supple-mented by genetic expression studies (or transcriptome) on Trichoderma reesei. This information will form the basis for an operational model helping to guide genetic engineering choices in order to obtain more efficient strains.
These advances will thus help bring down the cost of producing 2^nd-generation biofuel.

Example of T. reesei strain lines. Comparative study of their genome leads to identification of the key genes involved in cellulase production.

Publications

• S. Le Crom, W. Schackwitz, L. Pennacchio, JK. Magnusone, DE. Culley, JR. Collett, J. Martin, IS. Druzhinina, H. Mathis, F. Monot, B. Seiboth, B. Cherry, M. Rey, R. Berka, CP. Kubicek, SE. Baker, and A. Margeot, Proc. Nat. Sci. USA, Volume 106, n°38, pp 16151–16156. DOI: 0.1073/pnas.0905848106

>> See also IFPEN Publications database