Single cell protein can be produced on a number of different substrates, often this is done to reduce the Biological Oxidation Demand of the effluent streams leaving various type of agricultural processing plants.
A wide range of substrates can be used to grow microbial proteins (5)(AGRIS 1998-005657)(Kuhad, 1997). Various materials can be used as a substrate for producing single cell protein (whey, orange peel residue, sweet orange residue, sugarcane bagasse, paper mill waste, rice husks, wheat straw residue, cassava waste, sugar beet pulp, coconut waste, yam waste, banana pulp, mango waste, grape waste, sweet potato, (A)(CAB N215145)(Vaccarino, 1989); (B)(CAB M550935) (Swaminathan, 1989);(G)(CAB M457080)(Bajpai, 1988); (D)(CAB D319281)(Mathur, 1988); (E)(CAB M507533)(Nwabueze, 1987); (F)(CAB M507592)(El-Shawarby, 1987), (H)(CAB M470931)(Khaled, 1985); (I)(CAB N175836)(Pandey, 1988), (J)(CAB N175844)(Aderiye, 1988), (N)(CAB M389417)(Aker, 1987), (U)(CAB N918111)(Kahlon, 1986), (V)(CAB M693710)(Manilal, 1991), (W)(CAB M694368)(Malathi, 1989), (X)(CAB M681401)(Kuzmanova, 1990), (Y)(CAB D455606)(Zayed, 1991), (AA)(CAB M625510)(El-Refai, 1990), (AC)(CAB N274192)(Bugarski, 1988), (AD)(CAB N266858)(Guo, 1989), (AE)(CAB N252423)(Rashad, 1990), (AH)(CAB 940311026)(Rodriguez, 1993), (AK)(CAB 971300120)(Yulinery, 1995).
Methods available for concentrating include, filtration, precipitation, coagulation, centrifugation, and the use of semi-permeable membranes. These de-watering methods require equipment that is quite expensive and would not be suitable for most small-scale operations. Removal of the amount of water necessary to stabilize the material for storage, in most instances, is not currently economical. Single cell protein must be dried to about 10 % moisture, or condensed and acidified to prevent spoilage from occurring, or fed shortly after being produced.