Optimization of bioprotein production from palm pressed fiber by Aspergillus terreus UniMAP AA-1 for fish feed application

Abstract

Optimization of three parameters, temperature (25 ˚C - 35 ˚C), substrate concentration (40 % - 60 %) and inoculum size (5 % (w/v) – 15 % (w/v)) were investigated and optimized by Response Surface Methodology (RSM): Central Composite Design (CCD) for optimal condition of bioprotein production by Aspergillus terreus UniMAP AA-1. A second order polynomial equation was fitted and the optimum condition was established. The result showed that the temperature was a critical factor followed by inoculum size in terms of its effect on bioprotein production. The optimum condition for Aspergillus terreus UniMAP AA-1 to produce bioprotein about 0.78 mg/mL by solid state fermentation using palm pressed fiber (PPF) are at 32 ˚C temperature, 40% substrate concentration and 8 % (w/v) inoculum size. The predicted optimal parameters were tested in the laboratory and the percentage errors are below than 0.5 % recorded.