Comparative Study of the Extracellular Holocellulolytic Activity of <i>Fusarium solani</i> and <i>Aspergillus</i> sp. in Corn Stover

Fungal holocellulases are interesting for their possible applications in the bioconversion of corn crop residues into molecules with technological significance. Holocellulase (xylanases and cellulases) production from <i>Fusarium solani</i> and <i>Aspergillus</i> sp. with corn stover as a carbon source was compared using a Box–Wilson design. The fungal holocellulase production was different in both fungi. For <i>F. solani</i>, the maximum endoxylanase and <i>β</i>-xylosidase activities were 14.15 U/mg and 0.75 U/mg at 84 h of fermentation on 350 g/L corn stover, while <i>Aspergillus</i> sp. was 5.90 U/mg and 0.03 U/mg, respectively, at 156 h and 1000 g/L corn stover. The production of holocellulases in both fungi was reduced with increasing carbon sources. The nitrogen source induced the holocellulases in <i>Aspergillus</i> sp., but not in <i>F. solani</i>. Interestingly, when verifying the optimal culture conditions, the production of endoxylanases by <i>F. solani</i> was higher when compared to the predicted value. With regard to the endoxylanase and <i>β</i>-xylosidase activities of <i>Aspergillus</i> sp., these were close to the predicted values. Based on the optimization model, <i>F. solani</i> and <i>Aspergillus</i> sp. produce an interesting holocellulolytic activity in a growth medium with corn stover as the only carbon source. The fermentation time and the amount of corn stover required to obtain maximum holocellulase production are possible advantages for <i>Fusarium solani</i> and <i>Aspergillus</i> sp., respectively.