A bioprocessing mode for simultaneous fungal biomass protein production and wastewater treatment using an external air-lift bioreactor

A pilot plant investigation for bioprocessing has been undertaken to develo p a simple, nonaseptic, low-cost single process for production of fungal bi omass protein (FBP) and wastewater treatment using starch processing wastew ater. It has been confirmed that the newly developed external air-lift bior eactor was very suitable for bioconversion of starch materials and FBP prod uction by the microfungi Aspergillus oryzae and Rhizopus arrhizus. Bioprodu ct yields of 8.5 g dm(-3) of FBP that contained 46-50% protein were obtaine d within a comparatively short retention time. A fungal biomass productivit y in a range of 0.85-0.92 g dm(-3) h(-1) and removals of total suspended so lids and 95% COD were achieved in batch, semi-continuous and continuous pro cesses. The operation modes of the semicontinuous and continuous processes demonstrated a high biological dynamics in fungal biomass productivity and COD reduction. The semi-continuous process appeared to be the most practica l mode. (C) 2001 Society of Chemical Industry.