Scale-up and Design Parameters Investigation on Rotating Drum Bioreactors

Scale-up and design parameters have been investigated in 5 liters rotating drum bioreactors. System applies for animal feed production from cassava waste material using solid-state fermentation. The course of fermentation was 96 hours and all parameters related to microbial growth were measured every 12 hours namely glucosamine content, %urea, %protein, % carbohydrate, and %fat. The solid was turned every time before the sampling to remove excess heat and prevent overheating of the system. Bed temperature was on-line measured and found to be the highest at 36-44 C after 12-24 hours fermentation depending on the substrate loading. Moisture content was slightly increased from approximately 49% to 57% during the fermentation course. At 96 hours, the lowest substrate loading of 200g gives the highest glucosamine content, 35 mg/g, and crude protein, 23%. In contrast, the lowest glucosamine content of 10 mg/g, and crude protein of 21% were found when the highest substrate 500 g was loaded. Similar results were also found for %urea, %protein, and %fat analysis.