2.  Those that aim to produce cell mass (biomass)  Those where the product is produced by the cells, eg enzyme or metabolite  Those that modify a compound which is added to the fermentation (biotransformation)

3.  Started with the production of Baker’s yeast for baking industries.  Microbial biomass for protein source.  Bacteria, yeast and fungi (eg spirulina)  Single cell protein (SCP) Single cell protein

4.  Beer, wine, food additives, cheese  Ethanol, acetone, butanol, enzymes  Antibiotics, monoclonal antibodies, vaccines  SCP  Waste treatment

5.  Production of steroids  Conversion of antibiotics

6. Culture typesSpecial Characteristics  Bacteria  Yeast  Fungi  Algae  Animal & plant cells  May be highy aerobic or thermophilic  May be highly aerobic  Can be mycelial, highly viscous cultures  Often require light for growth  Slow growing, delicate

7. UPSTREAM Medium preparation Inoculum Bioreactor DOWNSTREAM Separation BiomassProduct purification

8.  Operated by supplying an essential growth- limiting nutrient at a constant rate with the result that the culture density and growth rate adjust themselves to the supply.

9.  Operated by maintaining a constant cell density by supplying fresh medium as required.  It possesses a photocell system which continuously monitors the cell density and maintains this constant by controlling the medium inlet flowrate.