Leiotrametes sp BRFM 1775 v1.0
Picture from Sacha Grisel, INRA, Biodiversity and Biotechnology of Fungi, Marseilles, France
Picture from Sacha Grisel, INRA, Biodiversity and Biotechnology of Fungi, Marseilles, France

This genome was sequenced as part of the JGI CSP “Survey of the lignocellulolytic capabilities over the order Polyporales” project. Within Agaricomycotina, the order Polyporales is the major group of wood decayers in temperate and tropical forests. As such, Polyporales have a pivotal role in the global carbon cycle. Polyporales include a large number of white-rot filamentous fungi able to totally degrade lignin from wood through the production of extracellular lignin-degrading enzymes including laccases, lignin peroxidases and manganese peroxidases. Lignocellulose is a high potential renewable resource for the production of biofuels and chemicals, including high-value chemicals, from biomass. As a consequence, white-rot filamentous fungi have a high potential for biotechnological processes, particularly for lignocellulosic feedstock biorefinery applications.

Leiotrametes sp. is a tropical species that belongs to the proposed novel genus Leiotrametes Welti & Courtec. gen. nov., nested in the Trametes clade of the core polyporoid group (Welti et al., Fungal Diversity, 2012; Mycobank MB 563399). The ability of this white rot fungus to deconstruct raw biomass has been demonstrated by saccharification assays on wheat straw (Berrin et al., AEM, 2012).

Leiotrametes is common in tropical areas. Both molecular markers and morphological features distinguish Leiotrametes from the core genus Trametes. The main characteristic separating Leiotrametes from Trametes and Pycnoporus genera is the glabrous upper surface, the lack of black line under the pileipellis and the lack of parietal crystals. Another interesting character is the brown resinous substance filling the lumen of the skeletal hyphae in the pileipellis, particularly those concentrated in the narrow grayish concentric zones. The lamellate hymenophore shows variable structure within  Leiotrametes sp. according to the specimen (mainly daedalean, mainly lamellate, or a mixed pattern).

The genome sequencing for Leiotrametes sp. will allow exploration for novel biocatalysts and deepen our understanding on the functional diversity among Polyporales, i.e. enzymatic capabilities linked to plant cell wall modifications.

References

Welti S, Moreau P-A, Favel A, Courtecuisse R, Haon M, Navarro D, Taussac S, Lesage-Meessen L. (2012). Molecular phylogeny of Trametes and related genera, and description of a new genus Leiotrametes. Fungal Diversity. 55, 47-64.

Berrin JG, Navarro D, Couturier M, Olivé C, Grisel S, Haon M, Taussac S, Lechat C, Courtecuisse R, Favel A, Coutinho PM, Lesage-Meessen L. (2012). Exploring the Natural Fungal Biodiversity of Tropical and Temperate Forests toward Improvement of Biomass Conversion. Applied and Environmental Microbiology, 78(18), 6483–6490.