MAINTENANCE OF HEAT AND WATER BALANCES AS A SCALE-UP CRITERION FOR THE PRODUCTION OF ETHANOL BY SCHWANNIOMYCES-CASTELLII IN A SOLID-STATE FERMENTATION SYSTEM

The scale-up of column fermenters by 6 to 410 gravimetric scale factors, from 10 g moist substrate size, has been achieved efficiently by maintaining heat and water balances in the media. The data on the patterns of ethanol production, biomass formation, the concentration of different carbohydrates, dry matter and pH values against time were of equal magnitude in 10- and 60-g size column fermenters. The reactors of 60-, 370- and 4100-g sizes also compared well in respect of O2 consumption, CO2 evolution and the specific growth rates in aerobic and anaerobic fermentation phases. The overall productivities of ethanol were similar in all the four column fermenters. The ability to obtain the same results in all the fermenter sizes, in spite of the increases in the diameter and the height of the columns, indicates the high potential of this simple scale-up criterion which has not been used earlier for scale-up of any fermentation process.