11-04-2014, 04:30 PM
Bioreactor
What is a Bioreactor?
An apparatus for growing organisms (yeast, bacteria, or animal cells) under controlled conditions.
Used in industrial processes to produce pharmaceuticals, vaccines, or antibodies
Also used to convert raw materials into useful byproducts such as in the bioconversion of corn into ethanol.
Bioreactors supply a homogeneous (same throughout) environment by constantly stirring the contents.
Bioreactors give the cells a controlled environment by ensuring the same temperature, pH, and oxygen levels.
Bioreactor - Vessel
The bioreactor vessel is a container which holds the media and the cells
Vessels can be made of glass, stainless steel, or a durable plastic.
The durable plastic vessels are disposable (single-use).
All the additional parts of a bioreactor connect to the vessel.
The top of the vessel is called a head plate. On glass reactors, most additional parts are located on the head plate.
Bioreactor - Agitator
An agitator is required to mix the contents in the vessel to ensure a homogeneous environment.
Agitators consist of a shaft and impellers.
Mixing of the bioreactor is crucial in order to supply nutrients and oxygen to the culture and to maintain a constant pH and temperature.
Bioreactor - Sparger
The sparger is an apparatus used to introduce gasses into the vessel.
Spargers are located at the bottom of the vessel and consist of a tube with tiny holes for the gas to escape through into the culture.
The gas coming out of the sparger helps to aerate and mix the contents in the vessel, as well as supply oxygen to the cells.
Bioreactor – Cooling Jacket
Cells give off heat when growing and dividing.
To maintain a constant temperature in the reactor, the vessel is covered by a cooling jacket.
Coolant (cold water or glycol) flows through the cooling jacket to regulate the temperature.
The temperature is controlled by the flow rate of the coolant.
Bioreactor – Load Cell
A load cell is a scale that measures the weight of the bioreactor.
The bioreactor sits on a series of load cells that compress when weight is added to the vessel.
The weight of the bioreactor can be correlated to the volume of liquid in the vessel by using the density of the cell culture medium.
Weight = Density x Volume