AIPMT PMT – Biotechnology – Principles and Processes
• The term biotechnology is derived from a fusion of biology and technology. Biotechnology means any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use.
• Berg is often considered “Father of genetic engineering”. He was awarded Nobel Prize in 1980.
• A definition of biotechnology which covers both traditional views and modern molecular biotechnology has been given by EFB.
• The definition given by the European Federation of Biotechnology (EFB) is as follows: “The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services.”
• Man began employing microorganisms as early as 5,000 BC for making wine, vinegar, curd, leavened bread, etc. Such other processes, which are based on the natural capabilities of microorganisms, etc. are commonly considered as old biotechnology.
• The development of recombinant DNA technology has allowed to modify microorganisms and other organisms to create in them highly valuable, novel and naturally non-existent capabilities. It is also called as genetic engineering.
• Human insulin or humulin is produced from a transgenic E.colistrain after introducing DNA sequences corresponding to chains A and B of human insulin.
• Crop varieties and animal breeds with entirely new and highly useful traits are being/can be created with the help of recombinant DNA technology. These, and many similar examples constitute the new biotechnology.
• The science of recombinant technology took birth when Cohen and Boyer (1972) were able to introduce the piece of antibiotic resistance gene from a DNA into the plasmid of Salmonella typhimurium. This modified plasmid was then inserted into £ coli to get clones of recombinant DNA.
• Recombinant DNA technology involves cutting and pasting of desired DNA into the specified hosts.
Importance and scope of biotechnology
• Biotechnology is rapidly emerging as an area of activity which has the potential to impact all domains of human welfare, ranging from food processing, environmental protection to human health.
• The importance of biotechnology in India was highlighted by the 69th session of the Indian Science Congress held at Mysore in 1982. As a consequence, the government of India constituted a National Biotechnology Board (NBB) to encourage and coordinate research activities in biotechnology.
• In 1986, a separate Department of Biotechnology (DBT) was created within the Ministry of Science and Technology.
• Research centres for biotechnology have been organised at Indian Agricultural Research Institute (IARI), New Delhi; National Dairy Research Institute (NDRI), Karnal; and Indian Veterinary Research Institute (IVRI), Izat Nagar (near Bareilly, U.P.).The IARI centre has been named as National Research Centre on Plant Biotechnology it came into operation in 1993.
• In the past, biotechnology concentrated on the production of food and medicine. It also tried to solve environmental problems. In the nineteenth century, industries linked to the fermentation technology had grown tremendously.
• Large-scale production of proteins and enzymes can be carried out by applying bioprocess technology in fermentation.
• Applying the principles of biology, chemistry, and engineering science, processes are developed to create large quantities of chemicals, antibiotics, proteins and enzymes in an economical manner.
• Bioprocess technology includes media and buffer preparation, upstream and downstream processing.
• Upstream processing provides the microorganisms with the media, substrate, and the correct chemical environment to carry out the required biochemical reactions for obtaining the product.
• Downstream processing is the separation method to harvest the pure product from the fermentation medium. Thus, fermentation technology changed into biotechnology, now known as classical biotechnology.
• Modern biotechnology is mainly based on recombinant DNA (rDNA) and hybridoma technology, in addition to bioprocess technology. rDNA technology is the main tool used, to produce genetically-modified organisms, including plants, animals and microbes.
• If the DNA fragment introduced into a bacterium includes a gene for insulin or any other therapeutic protein or enzyme, then that bacterium would be able to produce that protein or enzyme in large quantities, by applying bioprocess technology.
Principles of Biotechnology
• The two main techniques that gave birth to modern biotechnology are:
• Genetic Engineering: It includes techniques to alter the nature of genetic material of host organisms by introducing foreign or recombinant DNA into these host organisms thereby changing their phenotype.
• Chemical Engineering: It involves maintenance of sterile, microbial contamination free conditions in chemical engineering processes, that allow growth of only the desired microorganism/eukaryotic cell in large quantities, for the manufacture of biotechnological products such as antibiotics, vaccines, enzymes, medicines, hormones, etc.
• Genetic engineering is based on the following important discoveries:
– Occurrence of plasmids in bacteria which replicate, alongwith, and independent of chromosomal DNA.
Isolation of ‘restriction endonuclease’ from the bacterium Haemophilus parainfluenzae, which can break DNA at specific sites. The enzyme was isolated by Arber, Nathan and Hamilton Smith
(awarded with Nobel Prize in 1978).
Conceptual development of the principles of genetic engineering
• A piece of DNA is not able to multiply itself in an organism, and can multiply only when it gets integrated into the genetic material of the recipient organism.
• The alien (foreign) piece of DNA is added to the recipient chromosome, which possesses the ability to replicate.
• A specific DNA sequence present in the chromosomal DNA, called the origin of replication (Ori), is responsible for initiating replication. Thus, an alien DNA linked with the origin of replication, can replicate and multiply itself in the host organism.
• It is also called cloning, i.e., forming multiple identical copies of any template DNA. Thus, genetic engineering is also called recombinant DNA technology or gene cloning.
Steps of genetic engineering or genetic modification:
• Three basic steps in creating genetically modified organism (GMO) or transgenic organism are:
– Identification of DNA with desirable genes.
– Introduction of the identified DNA into the host.
– Maintenance of introduced DNA in the host and transfer of the DNA to its progeny.