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What is a bioreactor?
It is a vessel or a fermenter for microbial or non-microbial cell culture
What are factors that determine the design of a bioreactor?
- Properties of biological agent
- The nature of raw material or substrate
- The nature of the product
- The way of processing- batch or continuous
- Mixing and gas exchange requirement
- Sterility maintenence
- Methods of validation and process control
- Technoeconomic consideration
What are the different types of bioreactors based on?
- Biological agents used for processing (microbial, non-microbial and enzyme reactors)
- Gas requirements (aerobic and anaerobic)
- Sterility (Non-aseptic and aseptic)
What does each of the following use?
Stirred tank Reactor
- Stirred- agitators and baffle plates
- Pneumatic- airlift
- Hydrodynamic- deep jet fermenter- liquid pump for external circulation
What could culturing and product formation be?
- In batch- closed system
- Continuous (Homogenous and Plug flow)
What is cell recycling?
Used in continous bioreactors where the cell density is reduced due to the removal of fermented product
What the the immobilized cell bioreactor designed to do and what is its application?
- Prevent washout of cells
- Maintain CO2 level
- Prevent build up of biomass
- Application- production of monoclonal antibodies
What are the operating modes of bioreactors?
- Batch- no additions after innoculation
- Fed-Batch- extra nutrients are added as the fermentation progresses
- Continuous- an open system where fresh medium is continuously added
What should a bioreactors control system determine?
Temp, pH, Pressure, Aeration, agitation.
What operations are involved in general bioprocessing?
- Agitation and mixing
- Heat Transfer
- Size reduction and enlargement
What is bioprocessing?
A technique in which microorganisms, living cells, or their components are used as bio-catalyst to produce a desired end product
What are two major causes of cell damage?
- Hydrodynamic force or shear forces
- Energy from bursting bubbles
What are the properties of an organism that is relevant for bioprocessing?
- Nature of strain (pathogenicity, toxin production, strain stability)
- Cell culture shape, size and morphology
- Cell membrane and transport system
- Cell nutrition
- Cell Growth Kinetics
- Correlation between growth and production formation
- Presence of regulatory enzymes
- Activities of intracellular and extracelluar proteases
What are the steps in bioprocessing?
- Preparation stage
- Raw material
- Conversion State
- Downstream processing
- Volume production
- Final Product Processing
What are enzymes?
- Protein Catalysts
- Can be produced by bioprocessing
- Affected by pH and temperature
- Very specific
What are the methods for size enlargement?
- Pressure compactment
- Tumbler and mixer agglomeration
- Spray dryers
What are the disadvantages of bioprocessing over chemical means?
- Easily contaminated
- Requires separation of wanted materials
- Results in Biological waste
- Relatively slow process (many steps)
What are the movement mixers?
- The entire container moves
- Container is stationary with internal device rotating
- A combination of the above two
What are the 2 types of impellers?
- Radial flow- not as efficient
- Axial flow (used for animal cells) lifts cells from the bottom
How do we reduce the size of cells?
- Mills, rollers, crushes
- Tissue cutting, homogenization, and mincing or extrusion
- Microbial tissue breaking
What is the purpose of size enlargement?
- Reduce direct contact
- Render powder free flowing
- Prevent caking or lumping
What are distillation categories based on?
- System compostion- Binary and Multicomponent distillation
- Processing mode- continuous and batch
- Processing Sequence
- -Stripping- removing Ligh from Heavy
- -Rectification- removing Heavy from Light
- Fractionation- removing by Strip/Recti at the same time
- -Complex Fractionation- a combination of all methods
Which has a large surface area to unit volume ratio, a large or small reactor? Which require addition and removal of heat?
- Small has large surface area and requires addition of heat
- Large has small surface area and requires removal of heat
What are some disciplines related to bioprocessing?
- Molecular Biology
What are enzyme properties in bioprocessing?
- Specificity- substrate range
- Stability- effects of pH and temperature range
- Solubility- medium for reaction, hydrophobic vs. hydrophillic
- Structure, charge, and size- for purification and recovery
What are the advantages of bioprocessing over chemical methods?
- Complex organic molecules cant be produced by chemical means
- Bioconversion has a higher yield
- Operate at a lower temperature and pH
- Isomeric compounds are easily excluded
- Very Specific
What is distillation?
It separates chemicals by the difference in how easily they vaporize
What are some cell types used in bioprocessing?
- Bacteria (gram + and -)
What is agitation?
Agitation is a process of mixing suspension of solids in a liquid to prevent chemical, physical and thermal gradients