화학공학소재연구정보센터
Journal of Chemical Technology and Biotechnology, Vol.59, No.4, 387-393, 1994
Continuous Ethanol-Production from Carob Pod Extract by Immobilized Saccharomyces-Cerevisiae in a Packed-Bed Reactor
The continuous production of ethanol from carob pod extract by immobilized Saccharomyces cerevisiae in a packed-bed reactor has been investigated. At a substrate concentration of 150 g dm-3, maximum ethanol productivity of 16 g dm-3 h-1 was obtained at D = 0.4 h-1 with 62.3% of theoretical yield and 83.6% sugars’ utilization. At a dilution rate of 0.1 h-1, optimal ethanol productivity was achieved in the pH range 3.5-5.5, temperature range 30-35-degrees-C and initial sugar concentration of 200 g dm-3. Maximum ethanol productivity of 24.5 g dm-3 h-1 was obtained at D = 0.5 h-1 with 58.8% of theoretical yield and 85% sugars’ utilization when non-sterilized carob pod extract containing 200 g dm-3 total sugars was used as feed material. The bioreactor system was operated at a constant dilution rate of 0.5 h-1 for 30 days without loss of the original immobilized yeast activity. In this case, the average ethanol productivity, ethanol yield (% of theoretical) and sugars’ utilization were 25 g dm-3 h-1, 58.8% and 85.5%, respectively.