Bioconversion of Waste Organic Matter into a Microbial Biomass Protein

摘要

Food processing industries produce large quantities of wastewater with a high organic content. Itis expensive to treat and dispose of this wastewater and it is a waste of organic resources. Thesewaste streams can be converted from an economic liability to a source of revenue in theproduction of a high quality single cell protein. Several studies have been carried out on theproduction of microbial biomass protein from food processing wastewater using aerobic yeastcultures. The main challenge seems to be prevention of bacterial infection and maintaining theselected cultures in a full-scale continuous flow reactor. The hypothesis behind this research isthat there is a range of operating conditions (e.g., SRT, pH, temperature) at which selectedmicroorganism cultures have a competitive advantage and can be maintained in the system by anatural selection process. The concept was demonstrated with wastewater from the production offurfural, but the proposed methodology can be applied to any organic contaminants andmicroorganisms cultures. The results of this study indicated that furfural production wastewatercan be effectively treated by aerobic yeast cultures to produce high quality microbial biomass. ACOD removal efficiency of 92-95% and complete furfural degradation was achieved in a singlestage process. A new approach for the design of biological processes aimed at the production ofmicrobial biomass protein was proposed. The proposed approach is based on maintaining theselected microorganisms cultures in the system using natural selection processes. A methodologyto define the range of operating conditions that prevent bacterial growth was proposed andverified in continuous flow experiments. Effluent soluble COD was significantly higher than theeffluent biodegradable COD predicted possibly due to formation of SMP associated withsubstrate biodegradation.