LC-MS/MS secretome analysis of Pleurotus ostreatus PC9 (wild type) and two transformants

The white rot fungi Pleurotus ostreatus was studied for its potential as a biological pretreatment agent, i.e- its potential for decomposing lignocellulosic biomass. P. ostreatus PC9 was manipulate to either overexpress or eliminate (by gene replacement) the transcriptional regulator CRE1, known to act as a repressor in the process of carbon catabolite repression. The parental PC9 and the two transformants were grown on microcrystalline cellulose and wheat straw (3 replicates each) and the content of the resulted secretomes was analyzed by LC-MS/MS. An extensive range of carbohydrate active enzymes (CAZymes) were affected by the modification of cre1 expression levels. The three fungi revealed also differentiation towards the carbon source used in the growth media.