Induction of cellulases and hemicellulases from Neurospora crassa under solid-state cultivation for bioconversion of sorghum bagasse into ethanol

The cellulolytic and hemicellulolytic system from the mesophilic fungus Neurospora crassa was produced under solid-state cultivation (SSC) on wheat straw and wheat bran mixtures. Following optimization of nitrogen source, pH and initial moisture of the growth medium, yields as high as 492.8, 1.08, 26.7, 297.8 and 0.132 (in U g−1 of carbon source) were obtained for endoglucanase, exoglucanase, β-glucosidase, xylanase and β-xylosidase, respectively. The potential of the multienzyme system was demonstrated for hydrolysis of sorghum bagasse (SB) into fermentable carbohydrates. N. crassa cells were found able to assimilate the majority of the released sugars and generated limited levels of other metabolic products during simultaneous saccharification and fermentation of this valuable substrate into ethanol.