Transcriptomic analysis of cellulolytic fungus Penicillium decumbens strains in response to different carbon sources

Digital gene expression profiling (DGE) was used to compare the responses of Penicillium decumbens strains to different carbon sources including glucose, cellulose and cellulose-wheat bran. In both wild-type strain 114-2 and cellulase hyperproducing mutant JU-A10-T, transcription of lignocellulolytic enzymes were significantly up-regulated in the presense of cellulose. Relative to 114-2, coordinated up-regulation of lignocellulolytic enzymes and down-regulation of amylases and proteases were observed in JU-A10-T, especially in the cellulose-wheat bran medium. The expression of the principal ß-glucosidase BGLI gene was not elevated in JU-A10-T, like the cellulases and hemicellulases, suggesting a different regulatory mechanism for this enzyme. Functional analysis of genes up-regulated in JU-A10-T relative to 114-2 also showed enrichment of proteins involved in amino acid synthesis, protein synthesis, and post-translational modification, compatible with the higher level of production of secreted proteins in JU-A10-T. Overall design: Examination of differential gene expressions by Penicillium decumbens strains 114-2 and JU-A10-T grown in three different media.