BIOTECHNOLOGY IN FOOD

BIO-ENGINEERED FOOD

Very basically, 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, (friendly) 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. In answer to such concerns, the FDA has issued the following evaluation guidelines by which a bioengineered food will be judged for approval: 1. Has the concentration of a plant's naturally occurring toxicant increased? 2. Has an allergic element not commonly found in the plant been introduced? 3. Have the levels of important nutrients changed? 4. Have accepted, established scientific practices been followed? 5. What are the effects on the environment?

RDNA TECHNOLOGY AND GENETIC ENGINEERING TWO VITAL WINGS OF BIOTECHNOLOGY

Generally, any technique that is used to make or modify the products of living organisms in order to improve plants or animals, or to develop useful microorganism. In modern terms, biotechnology has come to mean the use of cell and tissue culture, cell fusion, molecular biology, and in particular, recombinant deoxyribonucleic acid (DNA) technology to generate unique organisms with new traits or organisms that have the potential to produce specific products. Some examples of products in a number of important disciplines are described below.

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 extrachromosomal 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. See also Antibody.
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.
Genetic engineering has enabled the large-scale production of proteins which have great potential for treatment of heart attacks. Many human gene products, produced with genetic engineering technology, are being investigated for their potential use as commercial drugs. Recombinant technology has been employed to produce vaccines from subunits of viruses that the use of either live or inactivated viruses as immunizing agents is avoided. Cloned genes and specific, defined nucleic acid sequences can be used as a means of diagnosing infectious diseases or in identifying individuals with the potential for genetic disease. The specific nucleic acids used as probes are normally tagged with radioisotopes, and the DNAs of candidate individuals are tested by hybridization to the labeled probe. The technique has been used to detect latent viruses such as herpes, bacteria, mycoplasmas, and plasmodia, and to identify Huntington's disease, cystic fibrosis, and Duchenne muscular dystrophy. It is now also possible to put foreign genes into cells and to target them to specific regions of the recipient genome. This presents the possibility of developing specific therapies for hereditary diseases, exemplified by sickle-cell anemia.
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. Other organisms are being sought to degrade phenols, petroleum products, and other chlorinated compounds. See also Genetic engineering ,molecular biology.

WHAT IS BIOTECHNOLOGY

Biotechnology is a broad term that applies to all practical uses of living organisms—anything from microorganisms used in the fermentation of beer to the most sophisticated application of gene therapy. The term covers applications that are old and new, familiar and strange, sophisticated and simple. Biotechnology combines disciplines like genetic, molecular biology, biochemistry, embryology and cell biology, which are in turn linked to practical disciplines like chemical engineering, information technology.
Defined in this way, the term is almost too broad to be useful. One way of thinking about biotechnology is to consider two categories of activities: those that are traditional and familiar and those that are relatively new. Within each category can be found technologies that are genetic—that involve modifications of traits passed down from one generation to the next—and technologies that are not.
Although there are interesting issues connected with a number of biotechnologies—both old and new—most of UCS's work focuses on genetic engineering, a new genetic biotechnology.

A prime example of traditional genetic biotechnologies is selective breeding of plants and animals. The rudiments of selecting plants and animals with desirable traits and breeding them under controlled conditions probably go back to the dawn of civilization, but the expansion of knowledge about genetics and biology in this century has developed selective breeding into a powerful and sophisticated technology. New molecular approaches like marker-assisted breeding (which enhances traditional breeding through knowledge of which cultivars or breeds carry which trait) promise to enhance these approaches even further.
Traditional breeding technologies have been immensely successful, and indeed are largely responsible for the high yields associated with contemporary agriculture. These technologies should not be considered passé or out of date. For multigene traits like intrinsic yield and drought resistance, they surpass genetic engineering. This is because selective breeding operates on whole organisms—complete sets of coordinated genes—while genetic engineering is restricted to three or four gene transfers with little control over where the new genes are inserted. For the most important agronomic traits, traditional breeding remains the technology of choice.
Other traditional nongenetic biotechnologies include the fermentation of microorganisms to produce wine, beer, and cheese. Industry also uses microorganisms to produce various products such as enzymes for use in laundry detergents. In an effort to find microorganisms that produce large amounts of enzymes, scientists sometimes treat a batch of organisms with radiation or chemicals to randomly produce genetic alternations. The process, called mutagenesis, produces numerous genetic changes in the bacteria, among which might be a few that produce more of the desired product.

Many new biotechnologies do not involve modifications of traits passed on to the next generation. A good example is monoclonal antibodies (highly specific preparations of antibodies that bind to a single site on a protein), which have many diagnostic applications, including home pregnancy testing kits. Many biotechnology companies are engaged in these sophisticated, but noncontroversial, technologies.

By contrast, mammalian cloning is a new biotechnology that does not involve gene modification, but is nevertheless highly controversial. Cloning reproduces adult mammals by transplanting a nucleus from adult cells into an egg from which the nucleus has been removed and allowing the egg to develop in a surrogate manner. The resulting individuals are as similar to the adults from which the nuclei were taken as identical twins are to one another. Although this procedure has profound implications for human reproduction, it does not modify specific traits of an individual, but rather transfers a whole nucleus containing a complete set of genetic information.
The new technology that can affect future generations is genetic engineering, a technology based on the artificial manipulation and transfer of genetic material. This technology can move genes and the traits they dictate across natural boundaries—from one type of plant to another, from one type of animal to another, and even from a plant to an animal or an animal to a plant. Cells modified by these techniques pass the new genes and traits on to their offspring. Genetic engineering can apply to any kind of living organism from microorganisms to humans.
Genetic engineering can be applied to humans to replace or supplement defective genes. Where engineering is intended to cure disease, it is called gene therapy. Potential applications that are not related to disease, such as the modification of traits like height, are sometimes called genetic enhancement. Currently, most genetic engineering of humans is done on nonreproductive or somatic cells, like those from bone marrow. The effects of this somatic cell gene therapy are confined to the treated individual. By contrast, germ line gene therapy would modify reproductive cells, so that the modification could be passed on to future generations.