BIOTECHNOLOGY IN AGRICULTURAL SECTOR:
Biotechnology in one form or another has flourished since prehistoric times. When the first human beings realized that they could plant their own crops and breed their own animals, they learned to use biotechnology. The discovery that fruit juices fermented into wine or that milk could be converted into cheese or yogurt, or that beer could be made by fermenting solutions of malt and hops began the study of biotechnology. When the first bakers found that they could make a soft, spongy bread rather than a firm, thin cracker, they were acting as fledgling biotechnologists.
The development of agricultural biotechnology offers the opportunity to increase crop production, lower farming costs, improve food quality and safety and enhance environmental quality. This report describes the economic, scientific, and social factors that will influence the future of biotechnology in agriculture. The supply of biotechnology innovations and products will be affected by public policies and by expectations of producer and consumer demand for the products. The demand for biotechnology by farmers and food processors is derived from the expected profitability of using the technology as an input to production. Ultimately, the use of biotechnology in the farm sector will depend on consumer demand for the biotechnology derived agricultural product.
Agricultural biotechnology is a revolutionary tool that is transforming the agricultural sector. It has the potential to spur economic growth, increase productivity in the agricultural sector, reduce hunger and malnutrition, and lessens the environmental impact of agricultural production.
The development of genetically modified foods and other agricultural biotechnology products has generated significant public debate. The potential for creating foods enhanced for health benefits or increasing crop yields was tantalizing, but there was also widespread concern about the technology’s health and environmental risks.
The Pew Initiative on Food and Biotechnology spotlighted policy issues arising from these discussions and served as a credible, honest broker, bringing together people with differing viewpoints to examine the opportunities and challenges of agricultural biotechnology.
Recombinant DNA technology has opened new horizons in the study of gene function and the regulation of gene action. In particular, the ability to insert genes and their controlling nucleic acid sequences into new recipient organisms allows for the manipulation of these genes in order to examine their activity in unique environments, away from the constraints posed in their normal host. Genetic transformation normally is achieved easily with microorganisms; new genetic material may be inserted into them, either into their chromosomes or into extra chromosomal elements, the plasmids. Thus, bacteria and yeast can be created to metabolize specific products or to produce new products. Genetic engineering has allowed for significant advances in the understanding of the structure and mode of action of antibody molecules. Practical use of immunological techniques is pervasive in biotechnology.
Few commercial products have been marketed for use in plant agriculture, but many have been tested. Interest has centered on producing plants that are resistant to specific herbicides. This resistance would allow crops to be sprayed with the particular herbicide, and only the weeds would be killed, not the genetically engineered crop species. Resistances to plant virus diseases have been induced in a number of crop species by transforming plants with portions of the viral genome, in particular the virus's coat protein.
Biotechnology also holds great promise in the production of vaccines for use in maintaining the health of animals. Interferons are also being tested for their use in the management of specific diseases.
Animals may be transformed to carry genes from other species including humans and are being used to produce valuable drugs. For example, goats are being used to produce tissue plasminogen activator, which has been effective in dissolving blood clots.
Plant scientists have been amazed at the ease with which plants can be transformed to enable them to express foreign genes. This field has developed very rapidly since the first transformation of a plant was reported in 1982, and a number of transformation procedures are available.
Modified microorganisms are being developed with abilities to degrade hazardous wastes. Genes have been identified that are involved in the pathway known to degrade polychlorinated biphenyls, and some have been cloned and inserted into selected bacteria to degrade this compound in contaminated soil and water.
Food-related biotechnology is the process by which a specific gene or group of genes with desirable traits are removed from the DNA of one plant or animal cell and spliced into that of another. Such beneficial genes might come from animals, bacteria, fish, insects, plants and even humans. In some instances, genes that create problems (such as the natural softening of a tomato) are simply removed and not replaced. Tomatoes, for example, are generally picked green and gas-ripened later because, during shipping, they would become soft, bruised and unmarketable. A bioengineered tomato, however, can be picked ripe and shipped without softening. The objective of food biotechnology is to develop insect- and disease-resistant, shipping- and shelf-stable foods with improved appearance, texture and flavor. Additionally, biotechnology advocates say that the process will produce plants that are resistant to adverse weather conditions such as drought and frost, thereby increasing food production in previously prohibitive climate and soil conditions. They also envision increasing nutrient levels and decreasing pesticide usage through biotechnology.
On the other hand, critics argue that, because biotechnology is producing new foods not previously consumed by humans, the changes and potential risks relating to such things as toxins, allergens and reduced nutrients are unpredictable. They also worry that, because genetically altered foods are not required to be labeled, people with religious or lifestyle dietary restrictions might unintentionally consume prohibited foods.
Biotechnology is unique amongst the three principal technologies for the twenty-first century information technology, materials science, and biotechnology in being a sustainable technology based on renewable biological resources. Such natural resources include animals, plants, yeasts, and microorganisms and have formed mankind's nascent food and beverage industry for several millennia.
The early years of the ‘new’ biotechnology focused on the technologies required to clone, over express, purify, and administer biopharmaceuticals such as insulin, growth hormone, deficient in haemophilia, and erythropoietin, with some 200 other proteins currently in the pipeline. However, in the future, the most significant breakthroughs in human medicine will result from mapping and understanding the human genome in elucidating the exact sequence of the billions of nucleotides that constitute the estimated 30 000-40 000 genes that are the collective blueprint for human beings and are responsible for some 10 000 genetic disorders. Innovations in sequencing technology have ensured that the project moved ahead of schedule. With less than 5% of all human genes identified at the start of the project, it has become increasingly clear that each new gene discovery proffers new drugs for the diagnosis, treatment, and prevention of human disease. These drugs include therapeutic proteins, diagnostics, gene therapy reagents, and small molecules. A significant proportion of the human genome has been sequenced and many new human disease genes are being characterized. These advances will enable biotechnologists not only to measure disease potential and expand the applications for genomic diagnostics but also to devise fundamental new therapeutic approaches.
Genomics and genetic engineering are also playing a substantial role in the development of agricultural biotechnology. This sector is finally moving out from under the shadow of the biopharmaceutical community and is now competing in terms of publicity and investor attention. This is because $1 billion is considered an attractive market in the biopharmaceutical industry, whilst global agricultural markets can readily top $10 billion and the total end-use value of food, fibre and biomass is estimated to be over $1500 billion. The addressable market on which value can be added and costs cut is at least 6-7 times that of its pharmaceutical counterpart. Two of the factors that have encouraged biotechnologists to enter the genetically engineered food and plant arena are the desire of consumers for better tasting foods and a preference for products grown using fewer pesticides. Calgene was the first company to market a genetically improved tomato which could be ripened on the vine without softening and thereby result in improved taste and texture. Antisense technology was used to inhibit the enzyme polygalacturonase which degrades pectin in the cell wall. Similarly, laurate Canola is the world's first oilseed crop that has been genetically engineered to modify oil composition. Laurate is the key raw material used in the manufacture of soap, detergent, food, oleochemical, and personal care products. Other examples of transgenic agricultural crops include high stearate and myristate oils, low saturate oils, high solids tomatoes and potatoes, sweet minipeppers, modified lignin in paper pulp trees, pesticide-resistant plants, and biodegradeable plastics.
The early goals in the development of transgenic livestock were the increase of the meat and of the production characteristics of food animals. However, long research and development timelines and low projected profit margins, especially in developed nations where food is relatively inexpensive; have shifted priorities to the production of protein pharmaceuticals and nutraceuticals in the milk of transgenic animals. Milk has high natural protein content and is sequestered in a gland where its proteins exert little direct systemic effect. It provides a renewable production system that is capable of complex and specific ‘post-translational processing’: that is, modifications to the protein that occur after it has been synthesized as a polypeptide (such as conjugation with carbohydrate moieties), which can alter the biological or therapeutic properties of the protein. Such changes cannot easily be accomplished in conventional cell culture systems. As a result, the ‘biopharming’ focus has shifted to the production of human blood plasma proteins and other therapeutic proteins, in ruminants such as cows, sheep, and goats which are easy to milk.
The pharmaceutical, agrichemical, and specialty chemical industries are increasingly requiring molecules which have distinct left- or right-handed forms, so-called chiral compounds. Whilst chemical and biological techniques for producing single left- or right-handed forms are developing apace, it is apparent that no single approach is likely to dominate. Suppliers and customers alike must continue to draw upon the entire range of chemical, enzymatic, and whole-organism tools that are available to produce chiral compounds. Unfortunately, only 10% of the 25 000 or so enzymes found in nature have been identified and characterized, and, of these, only 25 are produced in large quantities. Despite some duplication in activity among enzymes, there is a need to characterize more in order to exploit their unique specificity and activity. However, barriers to enzyme scale-up include product inhibition and a general reluctance on the part of chemists to use water-based reagents in systems which are traditionally non-aqueous. Consequently, enzymes should be made more user-friendly both for bench chemists exploring novel synthetic strategies and for all stages in pharmaceutical scale-up. However, the biologists' toolbox for catalysis is expanding.
Biotechnology is also playing a role in ‘clean’ manufacturing. Nevertheless, various types of chemical manufacturing, metal plating, wood preserving, and petroleum refining industries currently generate hazardous wastes, comprising volatile organics, chlorinated and petroleum hydrocarbons, solvents, and heavy metals. Bioremediation with microbial consortia is being investigated as a means of cleaning up hazardous sites.Biotechnology is expected to contribute massively to the global economy, largely through the introduction of recombinant DNA technology to the production of biopharmaceuticals. In the future, biotechnology will concentrate on the complexity and interrelatedness of biology, with such targets as the human genome project; genetic medicine; gene and cell therapy; tissue engineering; vaccines; factors for transcribing DNA into RNA; signal transduction and the control of gene expression; managing ageing at the level of programmed cell death, and genes that control cell division; neurobiotechnology; agri-industrial biotechnology; drug delivery; cell adhesion and communication; and novel diagnostics. Needless to say, and subject to clarification of certain ethical and public acceptance issues, biotechnology is set to make an indelible contribution to human health and welfare well into the foreseeable future.
