Fusarium verticillioides secretome as a source of auxiliary enzymes to enhance saccharification of wheat straw

Fusarium verticillioides secretes enzymes (secretome), some of which might be potentially useful for saccharification of lignocellulosic biomass since supplementation of commercial cellulases from Trichoderma reesei with the F. verticillioides secretome improved the enzymatic release of glucose, xylose and arabinose from wheat straw by 24%, 88% and 68%, respectively. Determination of enzymatic activities revealed a broad range of hemicellulases and pectinases poorly represented in commercial cocktails. Proteomics approaches identified 57 proteins potentially involved in lignocellulose breakdown among a total of 166 secreted proteins. This analysis highlighted the presence of carbohydrate-active enzymes (CAZymes) targeting pectin (from glycoside hydrolase families GH5, GH27, GH28, GH43, GH51, GH54, GH62, GH88 and GH93, polysaccharide lyase family PL4 and carbohydrate esterase family CE8) and hemicelluloses (from glycoside hydrolase families GH3, GH10, GH11, GH30, GH39, GH43 and GH67). These data provide a first step towards the identification of candidates to supplement T. reesei enzyme preparations for lignocellulose hydrolysis.