The following points highlight the seven main applications of biotechnology in industry and healthcare. The applications are: 1. Improvement in Fermentation Products 2. Microbial Production of Synthetic Fuels 3. Microbial Mining or Bioleaching 4. Microbial Biomass and Single Cell Protein Production 5. Production of Enzymes and Human Proteins and Others.
Applications of Biotechnology in Industry and Healthcare:
- Improvement in Fermentation Products
- Microbial Production of Synthetic Fuels
- Microbial Mining or Bioleaching
- Microbial Biomass and Single Cell Protein Production
- Production of Enzymes and Human Proteins
- Production of Secondary Metabolites from Cultured Plant Cell
- Molecular Farming for Healthcare Products
Application # 1. Improvement in Fermentation Products:
This achievement can be done in different ways – by selection of improved strain, by transgene application into the microorganism, by using cheaper raw material, by manipulation of medium constituent as well as by simulation of the reactor (adjustment of different cultural conditions like pH, temp., etc.).
Products of microbial fermentation include primary metabolites, secondary metabolites, enzymes, proteins, capsular polysaccharides and cellular biomass (single cell protein).
Application # 2. Microbial Production of Synthetic Fuels:
Important fuels can be produced by using many microbes which include ethanol, methane, hydrogen and hydrocarbons. Zymomonas mobilis produces ethanol twice as rapidly as yeasts from carbohydrates. Methane which is used in various industrial purposes can be produced by Clostridia, Bacteriodes, Sclenomonas, Butyrovibrio, etc. from the waste.
Application # 3. Microbial Mining or Bioleaching:
The process of bioleaching recovers metals from ores which are not suitable for direct smelting because of their low content. The application of bioleaching process is of particular interest in case of uranium ore. Thiobacillus ferroxidans is the commonest organism which is involved in case of copper and uranium ore processing.
Application # 4. Microbial Biomass and Single Cell Protein Production:
Microbial product of commercial significance is the microbial biomass (the microbial cells themselves), e.g., commercially produced yeast cells, bacteria (Methylophilus methylotrophus), flavoring cheese from fungal biomass (Penicillium roquefortii).
Single cell proteins are the dried cells of microorganisms such as algae, certain bacteria, yeasts, moulds and some higher fungi. The protein percentages for various single cell proteins are high.
Application # 5. Production of Enzymes and Human Proteins:
Bulk of the enzymes is obtained from microbial source by fermentation process. Now several plant enzymes are being used like ‘papain’ from Carica papaya, ‘bromelain’ from Ananas cosmosus, ‘ficin’ from Ficus glabrata. These enzymes are used in meat tenderizing, as protein hydro lysates in beer industry, in clinical application, etc.
Recombinant DNA technology can be used for the improved production of enzymes and proteins. There are many human proteins which have long been believed or known to have therapeutic potential and their increased production has been achieved by using recombinant DNA technology (Fig. 18.25).
The gene coding for insulin with two polypeptides has been synthesized. Each synthetic gene was linked to a plasmid near the end of the β-galactosidase gene of E. coli. After the gene expression and the translation of mRNA into protein, the two polypeptides were cleaved from the enzyme and linked to form the complete insulin molecule.
Different workers also synthesized complementary DNA from RNA of rat pancreas with the help of reverse transcriptase which was inserted into pBR 322 plasmid in the middle of the gene for penicillinase. The plasmid also contained the structural genes for pro-insulin. The hybrid protein synthesized in the bacterial cell was penicillinase + pro-insulin from which insulin could be separated by trypsin.
Production of interferon took a vital position when human leucocyte interferon was engineered by yeast cells. A DNA sequence coding for human leucocyte interferon was attached to the yeast, alcohol dehydrogenase gene in a plasmid and introduced into ceils of Saccharomyces cerevisae.
The first human peptide hormone synthesized in a bacterial cell was somatostatin, which is one of a group of hormones secreted by hypothalamus, controls the release of several hormones from the pituitary.
The synthetic gene has been inserted into the plasmid, expression vector was constructed from the plasmid pBR 322, to which was added the control region and most of the β-galactosidase gene from the bacterial lac operon; and the gene was inserted next to β-galactosidase.
After the plasmid was introduced into the cells of the bacterium E. coli, the hormone was synthesized as a short peptide tail at the end of the enzyme (Fig. 18.26).
With the advent of techniques of recombinant DNA and gene cloning, several other human hormones are being produced on a commercial scale by isolating specific DNA sequences coding for those proteins/hormones. This is likely to enable clinical application and improve economic provision for their utility in several deficiencies.
Application # 6. Production of Secondary Metabolites from Cultured Plant Cell:
In recent years it has been shown that spectrum of compounds can be produced in culture which is beyond the ability of whole plants. By using different precursors several novel compounds of biomedical importance can be obtained.
Pharmaceutical compounds like shikonin is being produced as secondary products with the use of two-stage bioreactor by stimulating the growth phase with the application of different growth regulators.
Serpentine can be obtained from Catharanthus, pseudoephedrine from Ephedra. Plant cells also can be used to accomplish certain changes in the structure and composition of some industrially important chemicals. This conversion by means of a biological system is termed as biotransformation, e.g., digoxin, a cardiovascular drug, produced from digitoxin obtained from Digitalis lanata.
Application # 7. Molecular Farming for Healthcare Products:
Transgenic plants Pan be used as ‘factories’ for production of speciality chemicals and pharmaceuticals like sugars, fatty acids, wax materials as well as antibodies, edible vaccines. The progress is so far reaching that human antibody production through plant seeds has been achieved.
The method involves the introduction of heavy and light chains of immunoglobin genes into microbial vectors. In the next step, these are introduced into the leaf cells of two plants and cultured in vitro for regeneration of the plants.
The plants – one containing heavy and the other with light chain, are then hybridized. The hybrid brings light and heavy chains together, to form the complete immunoglobin (IgA + IgB) in the seeds. This hybrid plant can be utilized for large scale production of seeds containing antibody proteins.
Even antibodies presumed to be effective against cancer have been secured in tobacco seeds. The method is thus a synthesis of recombinant DNA, in vitro technique and conventional hybridization.
Hepatitis B surface antigen is produced in tobacco, rabies virus glycoprotein is produced in tomato, cholera toxin (S-subunit is being produced in potato and tobacco. Transgenic plants are being used as a source of antibodies which provide passive immunization.
One of the recent discoveries in the area of plant biotechnology, is the development of oral vaccine utilizing plant systems. The principle involves, the development of transgenic plants, containing subunits of toxic virus sequences or enterotoxin genes of bacteria like E. coli or Vibrio cholera.
The oral administration of potato or tobacco transgenic tissues led to the development of immunoglobin G and A antibodies. As such, oral administration of plant tissues for production of antibodies in the system is, in effect, a vaccination – the application of vaccine being oral. Such recombinant vaccines, may prove to be a cheaper substitute for expensive vaccination, both in terms of production and administration.