Advantages And Disadvsntges Of Fermentors

Question 1

Advantages of batch fermentation

Answer 1

• Flexible, can create different products in successive batches
• Simple equipment
• Identifiable optimum harvest time
• Simple, leave after adding medium and cells
• Operations can be concentrated in single shifts

Question 2

Disadvantages batch fermentation?

Answer 2

• Labour and service intensive
• Downtime for loading and cleaning
• Harvest optimum time may not fit scheduling requirements
• Inadequate/incomplete control of metabolism
• Model-based control
• Product synthesis and biomass synthesis may be incompatible

Question 3

Advantages of fed-batch fermentation?

Answer 3

• All advantages of batch fermentation (apart from single shift operation)
• High cell/product conc. are achievable @ high yields
• Phases optimised for growth and product synthesis can be operated
• Conditions can be matched to phase
• Precursors/inducers can be fed at right time
• Many operational strategies developed for fed batch

Question 4

Disadvantages of fed-batch fermentation?

Answer 4

• still labour intensive
• requires technical skill on hand to obtain desired concs.
• model based control can be problematic, hard to identify state of system

Question 5

Advantages of continuous operation

Answer 5

• steady state
• steady demand on services
• CSTR has simple kinetic basis for model based control strategies (easier to control)
• High productivity, no down time between batches
• Good for single product dedicated operation

Question 6

Disadvantages of continuous operation

Answer 6

• 24hr operation, requires full 3 shift cover
• Up and down stream operations need to match
• culture may be unstable over long periods
• lacks flexibility
• single CSTR unsuitable for secondary metabolite production, multiple CSTRs compromise control