Solid-state fermentation and bioremediation: development of a continuous process for the production of fungal tannase

A solid-state fermentation (SSF) process for the continuous production of t he enzyme tannase is currently being developed. This paper describes a labo ratory scale prototype reactor that was built with the specific aim in oper ating continuously with solid substrates and without inoculation of the fee d. Mixing, fungal growth and sporulation studies have been conducted as a b asis for successful operation of a truly continuous process. The mixing stu dies at different feed rates revealed a mixing pattern with near perfect mi xed flow and the solids mixing in the reactor have been characterised using a dispersion model. Lower biomass, tannase yield and sporulation rate were obtained in a rotating batch culture at 0.7 rpm compared to static batch c ulture, presumably due to the deleterious effect of shear. The results of t his and future research will be used in order to predict operation variable s in the continuous SSF process. (C) 2001 Elsevier Science B.V All rights r eserved.