Cultivation of Candida tropicalis in sugar cane hemicellulosic hydrolyzate for microbial protein production

Abstract

Sugar cane bagasse hemicellulosic fraction was hydrolyzed by treatment with 100 mg of sulfuric acid per gram of dry mass at 140 °C for 20 min. The hydrolyzate was used as the substrate to grow Candida tropicalis IZ 1824 in a 1.0-1 bioreactor at 30 °C; aeration at 1.0 and 2.0 vvm; stirring at 400 rpm and initial pH of 6.0. The kinetic parameters, calculated for both cultivations—at 1.0 and 2.0 wm—included: maximum growth rate (μmax) of 0.057 h−1 and 0.137 h−1, yield of 0.30 and 0.31 g/g and productivity (Qx) of 0.196 g/l per h and 0.202 g/l per h, respectively. The protein produced (31.3% of the total biomass) contains essential amino acids for animal feed.