On-site hydrolytic enzymes production from fungal co-cultivation of Bermuda grass and corn cob

Solid state fermentation (SSF) is used to produce industrial enzymes. The objective of this study was to use a co-culture of Aspergillus niger GS1 and Trichoderma reesei, grown on a mixture of Bermuda grass and corn cob to obtain fermented forage (FF) rich in hydrolytic enzymes, as a value added ingredient for animal feed. FPase, amylase and xylanase productivities (dry matter, DM) were 8.8, 181.4, and 42.1 U g−1 h−1, respectively (1 U = reducing sugars released min−1), after 12-16 h of SSF with C/N = 60. Cellulose, hemicellulose and lignin decreased 1.6-, 2.7- and 1.9-fold (DM), respectively. In vitro ruminal and true digestibility of DM was improved 2.4- and 1.4-fold. Ruminal digestion of FF reduced 1.32-fold the acetate:propionate ratio, which may reduce the environmental impact of ruminants feeding. On-site hydrolytic enzymes productivity using SSF without enzymes extraction could be of economic potential for digestibility improvement in animal feed.