Optimization Process in Reactor and Fermentor | BiotechStudies

OPTIMIZATION OF PROCESS IN REACTOR AND FERMENTOR

•  Optimization means maximum production.
• In any type of fermentation process in the reactor that is used to grow cell, it is necessary to monitor and control culture parameter such as :-
• 1). Dissolved oxygen concentration 2). PH 3). Degree of mixing 4). Temperature
• Change in any of these parameters can have a dramatic effect on the yield of cell and stability of the protein product.

1. Maximum oxygen demand= 

• the maxi. oxygen demand in a fermentation
•  Qmax= X Meu max./Yo2
• Here X= cell mass, Meu max. = Maximum specific growth rate, Yo2 = growth yield based on oxygen consumed.
• O2 is sparingly soluble in water. So it must be supplied continuously.
• However introducing air produce bubbles and thus rate of transfer of O2 to cell is insufficient. Thus, fermeter design should monitor these changes in the culture.

1. Maximum pH= 

• most of microorganisms grow between ph range 5.5 to 8.5
• However, culture metabolites are released into growth medium. Thus, ph must be monitored and either acid or base must be added as needed to maintain ph
• After adding fermentation broth should be mixed throughout so that ph is same in entire reaction vessel.

1. Temperature= 

• microorganisms grown at a temperature below optimum grow slowly and have a reduced rate of cellular production. 
• Whereas it grown at a temperature above the optimum growth there may be premature induction of expression of target Protein.
• If it is under control of temperature sensitive repressor or induction of heat shock response will produce protease that lower the yield of protein product.

1. Mixing=

•  mixing of microbial culture is important to assure an adequate supply of nutrients to the cell and prevention of accumulation of toxic metabolic by product in local and poor mix region.
• Effective mixing is easily attained with SS culture but one problem = scale of fermentation is increased.