Press release: Scientists decode genome of the dry rot fungus Serpula lacrymans

Nr. 152/2011 - 21.07.2011

Studies on evolutionary development and wood decomposition yield benefits for renewable energy forms

(pug) An international team of researchers, including Professor Ursula Kües and Dr. Andrzej Majcherczyk from the University of Göttingen, has decoded the genome of the harmful wood rot fungus Serpula lacrymans and compared it with the genomes of other fungi. Serpula lacrymans is a brown rot fungus that attacks dead wood, breaks down its cellulose, and in doing so, can cause immense damage to the wooden structures of buildings. Analyses of the mechanism of wood decomposition may help us to develop methods for producing renewable forms of energy. Additionally, the scientists managed for the first time to establish genetic parallels to the mycorrhizal fungi that live in symbiosis with tree roots and supply trees with nutrients: Both pests and beneficial organisms are only equipped with a reduced genetic makeup for enzymes for decomposing plant cell walls. For example, both have genes for decomposing the polysaccharide pectin, which is found in the outermost layer of the cell walls and glues plant cells together. On July 14, 2011, the findings of the study will be published online in the research journal "Science“.

The dry rot fungus Serpula lacrymans and mycorrhizal fungi and the previously sequenced edible mushroom, Laccaria bicolor, belong to the fungal subphylum Agaricomycotina (Basidiomycetes). The scientists showed that both species evolved from the same ancestors and during their further evolution, lost enzyme groups for decomposing lignin that – like cellulose – is another important component of the cell walls of wood. Dry rot fungi first have to chemically initiate the decomposition of cell walls before they can enzymatically digest the released cellulose fragments. Brown lignin is left over at the end. Therefore, genes specificfor decomposing cellulose fragments and other polysaccharides are multiplied.

Scientists from the Joint Genome Institute of the United States Energy Department as partners in the international research team established the DNA sequence of the dry rot fungus Serpula lacrymans genome. Using these raw data, this international team studied the evolutionary development and the process of wood decomposition. The Göttingen researchers identified protein compositions using ultramodern and sensitive "proteomics” techniques. As expected from the genome sequence data, they demonstrated that primarily a large variety of polysaccharide-decomposing enzymes are produced and secreted during growth on wood.

The analyses may contribute to find more direct approaches to better protect against the destructive dry rot fungus Serpula lacrymans. Moreover, the scientists want to use the knowledge gained on the different wood decomposition strategies of brown rot and the previously analysed lignin-decomposing white rot fungi for the production of renewable energy forms. Researchers in Professor Kües’s research group in Göttingen and around the world are working on the development of cost-effective and environmentally friendly enzymatic methods for the large scale production of biofuels from the renewable raw material.

Original publication:
Daniel C. Eastwood et al.: The plant cell wall decomposing machinery underlies the functional diversity of forest fungi, Science Express 14 July 2011


Contact address:
Professor Ursula Kües
Dr. Andrzej Majcherczyk
Georg-August University Göttingen
Faculty of Forest Sciences and Forest Ecology
Büsgen Institute – Division of Molecular Wood Biotechnology and Technical Mycology
Büsgenweg 2, 37077 Göttingen
Phone (0551) 39-7024, Fax (0551) 39-2705
ukuees@gwdg.de
Website: www.uni-goettingen.de/en/99683.html