4 Fermentation and Biochemical Engineering Handbook offed-batch operation are summarized in Table 3. In the table the fed-batch operation is divided into two basic models, one without feedback control and the other with feedback control. Fed-batch processes have been utilized to avoid substrate inhibition, glucose effect, and catabolite repression, as well as for auxotrophic mutants Table 1. Classification of Aerobic Fermentation Systems (a) Internal mechanical agitation reactors 1. Turbine-stirring installation 2. Stirred vessel with draft tube 3. Stirred vessel with suction tube (b) Extermal circulation reactors 1. Water jet aerator 2. Forced water jet aerator 3. Recycling aerator with fritted dis (c) Bubble column and air-loop reactors 1. Bubble column with fritted disc 2. Bubble column with a draft tube for gyration flow 3. Air lift reactor 4. Pressure cycle reactor 5. Sieve plate cascade system Table 2. Classification of Fermentation Processes 1. Batch process 2. Fed-batch process(semi-batch process) 3. Repeated fed-batch process(cyclic fed-batch process Repeated fed-batch process(semi-continuous process or cyclic 5. Continuous process4 Fermentation and Biochemical Engineering Handbook of fed-batch operation are summarized in Table 3. In the table the fed-batch operation is divided into two basic models, one without feedback control and the other with feedback control. Fed-batch processes have been utilized to avoid substrate inhibition, glucose effect, and catabolite repression, as well as for auxotrophic mutants. Table 1. Classification of Aerobic Fermentation Systems (a) Internal mechanical agitation reactors 1. Turbine-stimng installation 2. Stirred vessel with draft tube 3. Stirred vessel with suction tube (b) External circulation reactors 1. Water jet aerator 2. Forced water jet aerator 3. Recycling aerator with fritted disc (c) Bubble column and air-loop reactors 1. Bubble column with fritted disc 2. Bubble column with a draft tube for gyration flow 3. Air lift reactor 4. Pressure cycle reactor 5. Sieve plate cascade system Table 2. Classification of Fermentation Processes 1. Batch process 2. Fed-batch process (semi-batch process) 3. 4. Repeated fed-batch process (cyclic fed-batch process) Repeated fed-batch process (semi-continuous process or cyclic batch process) 5. Continuous process