Genome-wide transcriptomic analysis of a superior biomass-degrading strain of A-fumigatus revealed active lignocellulose-degrading genes

Background: Various saprotrophic microorganisms, especially filamentous fungi, can efficiently degrade lignocellulose that is one of the most abundant natural materials on earth. It consists of complex carbohydrates and aromatic polymers found in the plant cell wall and thus in plant debris. Aspergillus fumigatus Z5 was isolated from compost heaps and showed highly efficient plant biomass-degradation capability. Results: The 29-million base-pair genome of Z5 was sequenced and 9540 protein-coding genes were predicted and annotated. Genome analysis revealed an impressive array of genes encoding cellulases, hemicellulases and pectinases involved in lignocellulosic biomass degradation. Transcriptional responses of A. fumigatus Z5 induced by sucrose, oat spelt xylan, Avicel PH-101 and rice straw were compared. There were 444, 1711 and 1386 significantly differently expressed genes in xylan, cellulose and rice straw, respectively, when compared to sucrose as a control condition. Conclusions: Combined analysis of the genomic and transcriptomic data provides a comprehensive understanding of the responding mechanisms to the most abundant natural polysaccharides in A. fumigatus. This study provides a basis for further analysis of genes shown to be highly induced in the presence of polysaccharide substrates and also the information which could prove useful for biomass degradation and heterologous protein expression.