Physical parameter optimization of feather protein hydrolysate production by Aspergillus terreus UniMAP AA-1 using submerged fermentation

Abstract

The rapid development of poultry industry has correlated with increased production of keratin containing wastes. Keratinous wastes can be easily fermented to produce useful product. A feather protein hydrolysate was produced by keratinolytic fungal Aspergillus terreus UniMAP AA-1 using submerged fermentation and physical parameters were optimized. To improve protein hydrolysate production, statistically based experimental designs were applied to optimize the physical parameters. Fractional factorial design (FFD) experiments showed that initial pH medium and fermentation time were the most significant factors affecting protein hydrolysate production. Further central composite design (CCD) experiments indicated that the optimal initial pH value and fermentation time were 10.0 and 10 days, respectively. Effects of physical parameters on protein hydrolysate production were tested and validated, and optimal results were obtained with initial pH value of 9.0 and 10 days of fermentation time. From the analysis of variance (ANOVA) using quadratic polynomial equation, maximum protein hydrolysate production of 6.30572 mg/mL was obtained. Fungal feather protein hydrolysate has the potential to be utilized as animal feed or as organic fertilizer, thus reducing the environmental crisis of feather waste from the poultry industry.