Process of foreign gene expression in a bioreactor
What is a Bioreactor?
This is a device that has been made to sustain biologically functioning surroundings. It may also be defined as a vessel in which a chemical process is executed. This process includes organisms and biochemically functioning material extracted from these microorganisms. They can be divided into aerobic and anaerobic. They are usually cylindrical in shape and are of various sizes generally composed of stainless steel. It may also be termed as a vessel that has been made to support the growth of cells or tissues. As far as classifications of bioreactors are concerned, depending on their mode of functioning, these bioreactors can be classified as a batch, fed-batch or continuous.
Types of Bioreactors Processes
There are several bioreactor types and applications, let us see what the bioreactor uses are –
Photobioreactor
This type of bioreactor requires a source of light to carry out the process. You could practically call any such translucent vessel as a photobioreactor. However, this term is more appropriate for enclosed storage space instead of an open system like a pond or a tank. They are used for the growth of organisms like algae, moss plants, cyanobacteria. They need light energy. Other than light, they do not need any kind of sugar or lips.
Sewage Treatment
This requires bioreactors for the cleaning purpose. Most of these systems are designed to utilize chemically inert substances with a large surface area. This helps in the growth of the biological film. Removal of the extra-biological film occurs in setting tanks or systems known as cyclones. Aerators are devices that provide oxygen to the sewage and biota for the sludge to become active. After which it is incorporated in the biological component.
Bioreactors for Specialized Tissues
A bioreactor can be used to ferment ethanol from corncob waste. Many mammals have cells and tissues which require a large surface area or a good support system for it to develop and grow. Higher organisms, which are known as auxotrophic, also need special growth support. This is a serious task when a huge quantity of cells is required to be cultured for therapeutic making reasons.
What are the Types of Bioreactors Found?
There are six kinds of bioreactors present, i.e. -
(1) Continuous Stirred Tank Bioreactors
(2) Bubble Column Bioreactors
(3) Airlift Bioreactors
(4) Fluidized Bed Bioreactors
(5) Packed Bed Bioreactors and
(6) Photo-Bioreactors.
What is Bioreactor Cell Culture?
The vessels designed for this purpose execute a biological function and are used in the culturing of aerobic cells, which in turn is done to perform cellular or enzymatic deactivation.
Interesting Facts about Bioreactors
The bioreactor was invented by Wolf, Schwarz, and Trinh. These three won the NASA "Inventor of the Year" for the interesting creations. The year 1990 saw Anderson and Schwarz licensing patents for the wall bioreactor technology that they created.
Bioreactors help in the survival of cells by sufficient delivery of necessary nutrients throughout the process. Bioreactors also help in tissue structure and organization.
In US dollars, Bioreactors can cost around $10,000 to install, and it works perfectly for around 10 years, after which the woods that have chipped off are required to be replaced.
A bioreactor process undergoes majorly three phases — upstream processing, bioreaction, and downstream processing — to transform the raw material into the finished product.
FAQs on Bioreactor in Foreign Gene Expression and Production
1. What is a bioreactor in the context of obtaining a foreign gene?
A bioreactor is a controlled vessel used to grow genetically modified cells or organisms that contain a foreign gene for large-scale production of a desired product. In genetic engineering, once a foreign gene is inserted into a host cell, the bioreactor provides optimal conditions for growth and gene expression.
- Maintains controlled temperature, pH, and oxygen levels
- Supplies nutrients for cell growth
- Ensures sterile conditions to prevent contamination
- Used for producing recombinant proteins like insulin
2. What is a foreign gene in biotechnology?
A foreign gene is a gene taken from one organism and introduced into another organism using recombinant DNA technology. This gene carries specific genetic information that allows the host to produce a new protein or trait.
- Also called a transgene
- Inserted using vectors like plasmids or viruses
- Common example: human insulin gene inserted into Escherichia coli
3. How is a foreign gene inserted into a host cell?
A foreign gene is inserted into a host cell using recombinant DNA technology and suitable vectors. The process involves cutting, joining, and transferring DNA into the host.
- Isolation of the desired gene using restriction enzymes
- Insertion into a vector like a plasmid using DNA ligase
- Transfer of recombinant vector into host cells (transformation)
- Selection of successfully modified cells
4. Why is a bioreactor used after inserting a foreign gene?
A bioreactor is used after inserting a foreign gene to allow large-scale growth of genetically modified cells and efficient production of the desired recombinant product. Once the gene is expressed, the product must be produced in high quantities.
- Provides optimal environmental conditions
- Increases cell biomass
- Enhances gene expression and protein yield
- Used in industrial production of vaccines, hormones, and enzymes
5. What are the main types of bioreactors used in genetic engineering?
The main types of bioreactors used in genetic engineering are based on their design and mixing mechanisms for culturing recombinant cells. Each type supports efficient foreign gene expression.
- Stirred-tank bioreactor – uses mechanical agitation for uniform mixing
- Airlift bioreactor – circulates air to mix culture medium
- Batch bioreactor – nutrients supplied at the beginning only
- Continuous bioreactor – fresh medium added and product removed continuously
6. What is the role of plasmids in obtaining a foreign gene?
A plasmid acts as a vector that carries the foreign gene into a host cell during genetic engineering. It is a small, circular DNA molecule found in bacteria that replicates independently.
- Contains an origin of replication
- Has selectable marker genes like antibiotic resistance
- Allows insertion of foreign DNA at specific restriction sites
- Widely used in cloning and recombinant protein production
7. How does a stirred-tank bioreactor work?
A stirred-tank bioreactor works by mechanically agitating the culture medium to ensure uniform mixing and oxygen distribution for recombinant cells. It is the most commonly used bioreactor in biotechnology.
- Contains impellers for mixing
- Maintains controlled temperature and pH
- Supplies sterile air or oxygen
- Used for large-scale production of recombinant proteins
8. What conditions are maintained inside a bioreactor for foreign gene expression?
A bioreactor maintains optimal physical and chemical conditions to ensure efficient foreign gene expression and cell growth. These conditions directly affect recombinant protein yield.
- Controlled temperature
- Stable pH
- Adequate dissolved oxygen
- Sterile nutrient supply
- Proper agitation and mixing
9. What is the difference between a bioreactor and a fermenter?
A bioreactor is a broad term for any vessel used to grow cells or tissues under controlled conditions, while a fermenter specifically refers to a bioreactor used for microbial fermentation. In biotechnology, the terms are sometimes used interchangeably, but fermenters mainly involve microbial processes.
- Bioreactor: used for microbes, animal cells, or plant cells
- Fermenter: mainly used for bacteria and yeast
- Both maintain controlled growth conditions
10. What is an example of obtaining a foreign gene product using a bioreactor?
A classic example of obtaining a foreign gene product using a bioreactor is the production of human insulin using genetically modified Escherichia coli. The human insulin gene is inserted into a bacterial plasmid and expressed in large quantities.
- Human insulin gene isolated and cloned into plasmid
- Recombinant plasmid introduced into E. coli
- Modified bacteria grown in a stirred-tank bioreactor
- Insulin purified from the culture for medical use
