An insight into transcriptome of Cyathus bulleri for lignocellulase expression on wheat bran

To identify enzymes that can be effectively used for hydrolysis of lignocellulosic biomass, an attractive carbon source in biorefineries, transcriptome analysis was carried out of wheat bran grown fungus, Cyathus bulleri. A comprehensive set of transcripts, encoding carbohydrate active enzymes, were identified. These belonged to 55, 32, 12, 11 and 7 different families of the enzyme classes of Glycoside Hydrolases (GHs), Glycosyl Transferases (GTs), Auxiliary Activities (AAs), Carbohydrate Esterases (CEs) and Polysaccharide Lyases (PLs) respectively. Higher levels of transcripts were obtained for proteins encoding cellulose and hemicellulose degrading activities (of the GH class) with the highest diversity found in the transcripts encoding the hemicellulases. Several transcripts encoding pectin degrading activity were also identified indicating close association of the pectin with the cellulose/hemicellulose in the cell wall of this fungus. Transcripts encoding ligninases were categorized into Cu radical oxidase, Glucose-Methanol-Choline oxidoreductase (with 37 different transcripts in the AA3 sub-family), Laccase and Manganese peroxidases. Temporal gene expression profile for laccase isoforms was studied to understand their role in lignin degradation. To our knowledge, this is the first analysis of the transcriptome of a member belonging to the family Nidulariaceae.