Application of genetic engineering

 

Genetic engineering

Today biotechnology products are produced from genetically engineered bacteria, plants and animals.Organisms that have a foreign gene inserted into them are called transgenic organisms or genetically modified organisms.
In our this article we will discuss the importance of genetic engineering with the reference of transgenic bacteria.....
Transgenic Bacteria
The bacteria with foreign DNA is called transgenic bacteria.These GM Bacteria are now used for...
production of enzymes
The commercial production and use of enzymes is already a well established part of the biotechnology industry. Enzymes are used in brewing, food processing, textile manufacture, the leather industry, washing powders, medical applications, and basic scientific research, to name just a few examples. In many cases the enzymes are prepared from natural sources, but in recent years there has been a move towards the use of enzymes produced by rDNA bacteria.
enzymes for food industry
In the food industry, one area that has involved the use of recombinant enzyme is the production of cheese. In cheese manufacture, rennet (also known as rennin, chymase, or chymosin) has been used as part of the process. Chymosin is a protease that is involved in the coagulation of milk.Chymosin is now available as a recombinant-derived preparation from E. coli, Kluyveromyces lactis, and Aspergillus niger. Recombinant chymosin was first developed in 1981, approved in 1988, such other enzymes are now being obtained by these GMO  bacterias.
Enzymes for washing products
An example of recombinant-derived proteins in consumer products is the use of enzymes in washing powder. Proteases and lipases are commonly used to assist cleaning by degradation of protein and lipid-based staining. A recombinant lipase was developed in 1988 by Novo Nordisk A/V (now known as Novozymes). The company is the largest supplier of enzymes for commercial use in cleaning applications. Their recombinant lipase was known as LipolaseTM, which was the first commercial enzyme developed using rDNA technology and the first lipase used in detergents. A further development involved an engineered variant of Lipolase called Lipolase Ultra, which gives enhanced fat removal at low wash temperatures.
Synthesis of pharmaceutical products
A foreign gene is replicated and expressed in these transgenic bacteria and thus a large number of pharmaceutical products are obtained.These products are now available in markets.Some of these products are Insulin, human growth hormone, Tissue plasminogen activactor, haemophilia factor Vlll, Hepatitis B vaccine.
In the past Insulin was extracted from the pancrease glands of cattle, pigs and from other animals.But this insulin was not like the human insulin so it often produce allergic reactions.But today the Insulin is being produced from GM (genetically modified) bacteria.
prior the rDNA technology HGH (human growth hormone) was manufactured by isolating it from pituitary gland tissues taken from human cadavers.In 1979 scientists produced HGH by inserting genes which code for for this hormone into plasmid which was implanted into Escherichia coli.
Glucosamine is used for osteoarthritis and is made by acid hydrolysis of chitin from shellfish waste.Since many patients have shellfish allergies.Metabolic engineering of E.coli have enabled us to to produce glucosamine from this bacterium.
Promoting health in plants
Transgenic bacteria are used to promote health of plants.For examle a bacterium normally forms colonies in the roots of corn plants.Some genes from another bacterium have been inserted into these bacterium.These genes code for an insect toxin.The toxin protects the roots from insects.
Pseudomonas syringae is a bacterial specie with many members.These bacteria contain a protein that initiates the formation of ice-crystals at temperature below freezing.The growing ice crystals can rupture and damage plant cells.Researchers have now created an "ice_minus" strain of P.syringae with the help of genetic engineering.
Biodegradation
  Bacteria can degrade a particular substance.The ability of degradation can be enhanced by genetic engineering.For example these transgenic bacterias are used to clean up beaches after oil spills.
Biofilters
The transgenic bacteria can be used as biofilters in industries.These bacteria filter the airborne chemical pollutants.Thus these pollutants are prevented to enter into the air.They can remove sulfur from coal before burning it.They also help to clean up toxic waste dump. These bacteria are given suicide genes.These genes causes self-destruction of these bacteria, when their job is completed.
 Fuel Industry:
 In recent years, ethanol has found its use as an important chemical feed stock and as a fuel supplement. Ethanol is generally produced by fermenta​tion of some sugar (starch, cellulose) rich products with the help of yeast, Saccharomyces cerevisiae or sometimes with Kluyveromyces fragilis.
At present E. coli and Klebsiella planticola carrying genes from Z. mobilis have been developed which could utilize glucose and xylose as the substrate to give maximum yield of ethanol.
BioHydrometallurgy
 Bio-hydrometallurgy is a new branch of metallurgy that amalgamate metallurgy and biotechno​logy together. Extraction of metals from ores through conventional metallurgy involves smelting ores at high temperature, a process which is very much polluting and energy intensive approach.
However, bio-metallurgy is an approach which is environment friendly and can be used to extract metals from low grade ores in contrast to high grade ores used in conventional metallurgy which are gradu​ally becoming exhausted In bio-metallurgy, different bacterial species are being used for the extraction of metals from ores. For example, Thiobacillus ferrooxidans and related thiobacilli are used for copper extraction. Recently, genetically engineered strains of thiobacilli have been developed to increase the speed of extraction.
 Bio Mineralisation
It has been shown recently that some bacteria which are normal constituents of soil can deposit valuable metals like gold, silver etc. in soil. It is suggested that negatively charged polymer on the outside of the bacteria, attracts the positively charged gold particles in the soil. Thus, the metal particles clump together as grains that eventually form gold nuggets.
The process of gold deposition on the negatively charged polymers can continue even after the death of the bacteria. Naturally occurring bacteria involved in such biomine​ ralisation include Bacillus cereus, podomicrobium-like budding bacteria and Chlorella vul​garis.
It is suggested that genes responsible for mineralization in a variety of microbes can be isolated, cloned and transferred into E. coli, which may then help in metal deposi​tion more efficiently.