Production of cell-wall degrading enzymes by solid-state fermentation using agroindustrial residues as substrates

This study is focused in the production of cell-wall degrading enzymes (chitinase, beta-1,3-glucanase, endocellulase and exocellulase) by solid state fermentation using the fungus Metarhizium anisopliae IBCB 348. Different substrates (sugarcane bagasse, malt bagasse and white rice) supplemented with corn steep liquor, soybean meal and chitin were evaluated. A Plackett-Burman experimental design was applied to evaluate the effects of initial moisture content (60-80%, v/v), corn steep liquor (0-5%, w/w), soybean meal (0-5%, w/w) and inoculum concentration (10-30%, v/w) on enzymatic production. Sugarcane bagasse was the most suitable substrate for enzyme production, mainly chitinase. Maximum activities were 12.07 +/- 0.50, 11.54 +/- 6.96, 20.87 +/- 0.43 and 22.30 +/- 0.41 U.g(-1) for chitinase, beta 1,3-glucanase, endocellulase and exocellulase, respectively. The process condition used to obtain these activities were moisture content of 40 wt%, 10% (v/w) of inoculum, 28 degrees C during 8 days of fermentation. These results demonstrate the potential of solid state fermentation using Metarhizium anisopliae IBCB 348 in the production of hydrolytic enzymes.