Effects of fermenter type, xylanase addition and dual cultures on fungal fermentations of wheat pollard and bran

Pollard and bran were fermented by a selection of filamentous fungi to increase the protein content and availability for use as animal feed. Aspergillus terreus produced a product containing 32·6% crude protein (CP) after 16 days. Under identical environmental conditions, shallow-layer solid-state fermentations achieved higher CP yields than did tumbled or packed-column systems. When crude xylanase was added with A. terreus inoculum, a 5-day reduction in fermentation time was achieved resulting in a maximum CP content of 27%. A. terreus, Chaetomium virescens, Schizophyllum commune or Trichoderma reesei, in dual culture with one another or in combination with Phanerochaete chrysosporium, did not achieve higher final CP yields (after 16 days) than A. terreus alone. P. chrysosporium in combination with T. reesei and with S. commune resulted in the most rapid CP development of 26·1% and 26·4%, respectively, during the first 10 days.