Rapid and efficient enzymatic degradation of plant biomass into monomeric sugars is currently a major challenge for sustainable production of biochemicals and biofuels. The best studied and most widely used plant8208;degrading enzymes are produced by Trichoderma and Aspergillus species, and they are most effective over a temperature range of 40 - 50Â°C. As a consequence, these moderate temperatures have long reaction times for complete saccharification of plant biomass. It would therefore be desirable to have elevated hydrolysis temperatures using thermostable enzymes. The collection at the CBS Fungal Biodiversity Centre contains several thermophilic fungi, which produce thermostable enzymes up to 708208;80Â°C. A screening of 32 thermophilic species resulted in several candidates with interesting plant8208;degrading enzymes. Particularly the genus Myceliophthora contains isolates with rapid growth on complex polysaccharides. We elucidated the phylogeny of Myceliophthora isolates and distinguished 10 different species, of which four are thermophilic. The isolates with the fastest growth on crude plant material were divided in two species: M. thermophila and M. heterothallica. The new phylogenetic classification of M. heterothallica isolates was further supported by physiological differences between the two species. Also, in contrast to M. thermophila isolates, M. heterothallica has a functional sexual cycle. M. heterothallica isolates were studied in detail for their ability to release sugars from crude plant biomass. Furthermore, crossing experiments between M. heterothallica isolates resulted in offspring with an even higher potential in rapid and efficient enzymatic degradation of plant biomass.
Full conference title:
11 th European Conference on Fungal Genetics
- ECFG 11th (2012)