Production of Acetic Acid and Whey Protein from Cheese Whey in a Hybrid Reactor under Response Surface Optimized Conditions

Abstract

Experimental investigations were carried out in a membrane-integrated hybrid bio-reactor system for direct and continuous production of acetic acid and whey protein from waste cheese whey under response surface optimized conditions. In this novel scheme of fermentative production, using Acetobactor aceti, the major operating parameters such as temperature, concentrations of yeast extract, and glucose were optimized. Under the set of optimum operating conditions (temperature of 300 °C, pH of 6.0, yeast extract concentration of 15 g/L and glucose concentration of 44 g/ L), more than 95% pure acetic acid was produced with a concentration of 84.1 g/L, yield of 97.4% and productivity of 7.2 g/(L· h). Simultaneous production of whey protein powder makes the process more economically viable. Findings indicate that acetic acid could be produced directly and continuously from waste cheese whey with high productivity, yield and purity under response surface optimized conditions, in a simple, flexible, energy-saving and environmentally benign membrane-integrated hybrid reactor system.