Biotechnology - solution or problem?
In biotechnology, a living organism - either a whole organism, a cell, or a part of a cell, such as an enzyme - acts as an intermediary to transform a starting product into a desired end product. In fact, biotechnology is not a recent invention. When we use yeast to make bread, we are using principles of biotechnology - yeast is a living organism. We did not have to wait until 1953 for Watson and Crick to discover the structure of DNA, or the developments in molecular and cell biology of the 1970s, says Albert Sasson, Doctor of Natural Sciences and Special Adviser to the Director-General of UNESCO. Pasteur was a biotechnologist, as was Alexander Fleming, who used a variety of mould (Penicillium notatum) to produce an antibiotic that helps to fight against disease.
Biotechnology and genetic engineering
Genetic engineering is not a biotechnology, but a technique, developed through decades of basic research in cell and molecular biology. Today it is possible to identify a gene, to isolate it, cut it, insert it and transfer it. This is what we understand as genetic manipulation or genetic engineering. Genetic engineering has made it possible to improve our understanding of the living organism and to apply this knowledge to the life and activities of man - for example, in food, agricultural production, forestry, animal rearing, horticulture, public health, vaccines, reproduction, the production of energy and combatting pollution.
Most biotechnologies pose no ethical or social problems and are useful, says Sasson. For example by using micro-propagation you can make thousands of identical plants and can supply agriculture with potatoes, strawberries and so on all year round. What is more, they are virus-free, so production is greater. But there is no genetic engineering involved. All we have done is to exploit a natural property of plants cells - called totipotency - to produce plants that are identical to the one the cell was taken from. There are thousands of millions of these 'test tube plants' or 'vitroplants' produced in the world. The flower market is enormous. Even poor countries have become major producers of vitroplants.
Forestry also makes use of this technique. Since man has been cultivating plants, he has been cross-breeding them to improve them. But seeds take a long time to germinate. Now, using these new techniques, once a plant with valuable qualities, like robustness, speed of growth, juicy fruit, has been found, it can be reproduced by the million. With genetic engineering, we accelerate the conventional process of isolating genes and transferring them. Instead of having a new strain of wheat in ten years we have it in five.
The technique depends on isolating the gene whose function one wants to use. A current - but controversial - application is resistance to disease. More than 30 percent of crop losses at harvest are due to pests. Biotechnology can reduce these post-harvest losses by making seeds more resistant to parasites and by increasing production. Genetic engineering can contribute 10 percent or 20 percent to such increases, says Sasson. The rest comes from irrigation, pesticides, soil conservation. But, he says, biotechnology is not a panacea - we will not abandon conventional techniques.
Genetically modified foods
Using genetic engineering it is possible to insert a gene into a plant, so that it is passed on to subsequent generations. For example, some insect pests are sensitive to a toxin produced by a common soil bacterium. Conventionally, a solution of the toxin is sprayed onto plants, to be ingested by insects eating the leaves. But, if it rains, the spray will be washed onto the soil and have no effect. Similarly, if there is a drought, the spray will dry out and have less of an effect. With genetic engineering it is possible to isolate the bacterium gene that controls synthesis of this toxin and insert it into the plant. When the caterpillar eats the leaf with the bacterium gene, the gene will produce a toxin and kill the larva.
The planting of these kinds of genetically modified organisms (GMO) has met with opposition in some countries. The UK still has a temporary ban on commercial planting of GM crops until risk assessment trials have been carried out. And the Spanish government is asking companies that produce or plant genetically modified crops to contribute to a US$100 million insurance fund to cover environmental accidents1. But, in 1998, farmers in USA had planted 20 million acres (8 million hectares) of farmland with genetically modified maize, potatoes and cotton.
One of the risks is that the GMO will interfere with the environment. Pollen carried on the wind could pollinate wild varieties of the modified plant, producing hybrids with unknown characteristics. But, says Sasson, pollen only travels from 100 metres to one kilometre. So the transgenic variety has to be separated by one kilometre from other varieties. We must take these risks into consideration. Wild varieties of colza exist in parts of Europe, such as France, so we should wait before introducing genetically-modified varieties. But there are no wild varieties of corn in France. We must do a risk-benefit analysis for each case, for each plant and environment. Apart from carrying out tests to guarantee that the food is safe, some countries also insist that genetically modified food products - or those with GM ingredients - should say so on the label.
Genetic engineering in medicine
Insulin, growth hormone and diagnostic tests (e.g. for pregnancy or HIV) are made using genetic engineering techniques. But, perhaps because drugs are subjected to batteries of tests lasting as long as ten years, there is less public concern. Plants - like potatoes or bananas - can be modified to produce a vaccine. And some drugs can come from transgenic animals whose genetic material has been modified to produce a therapeutic protein in their milk. More controversial, though, is the transfer of human genes to animals, such as the pig, so that a kidney or a lung from the animal can be transplanted to human patients without being rejected.
When we come to man, says Sasson, we can no longer talk of biotechnology. We cannot use man as the living milieu to produce something.
Several governments have already acted to impose limits on the use of genetic engineering on humans, particularly where the changes will be passed on to an individual's children. And when UNESCO's International Bioethics Committee drafted a Universal Declaration on the Human Genome and Human Rights, it was adopted by all 186 Member States (11 November 1997) and subsequently by the UN General Assembly (9 December 1998).
1 See Nature vol 397, 25 February 1999 p 636
Biotechnology and development|
The implications of biotechnologies for developing countries are mixed. On the one hand they present solutions to overcoming poor crop yields, while reducing crop losses due to pests and drought. Currently some 30 percent of crops are lost through pests. On the other hand, according to a recent report from the Food and Agriculture Organization (FAO) agriculture committee, if biotechnology is linked to intensive farming, this can lead to loss of biodiversity and soil degradation. Meanwhile, there is a danger of over-dependence on outside expertise and/or products at the expense of local capacity building and development of produce that uses traditional knowledge, skills and natural resources.
The need for some changes in agricultural practice was stressed at the FAO World Food Summit held in Rome in November 1996. The meeting highlighted some distressing statistics about food security:
- an estimated one in five (841 million) people in developing countries are hungry (food-energy deficient);
- some 150 million children are underweight and 50 million are wasted;
- vitamin deficiency affects millions of people (2 billion people are iron deficient).
There is no doubt about some of the positive contributions of biotechnology's 'green revolution' that started in the 1970s. New, dwarf hybrid strains of grain crops like wheat and rice have multiplied yield four to ten times in India, for example, compared to yields in 1947 at the time of independence. At the same time, new, drought-resistant crops are being grown in arid regions such as the Sahel, while genetically modified pest-resistant crops could reduce the need for toxic insecticides. Developing countries can develop strengths in some biotechnologies without the need for high-tech facilities - eg. the manufacture of nitrogen-fixing biological fertilisers1. Kenya is a major exporter of cut flowers.
But the FAO2, has also expressed reservations about the value of biotechnologies for developing countries, unless they are linked to more sustainable, organic farming techniques. Organic farming - which is compatible with some biotechnological innovations, such as biological fertilisers and pest-resistant crops - has usually been considered uneconomical for developing countries. But, says FAO: Organic agriculture can contribute to local food security in several ways. Organic farmers do not incur high initial expenses so less money is borrowed. Synthetic inputs, unaffordable to an increasing number of resource-poor farmers due to decreased subsidies and the need for foreign currency, are not used. Organic soil improvement may be the only economically sound system for resource-poor, small-scale farmers. Labour-intensive organic farming also provides employment in rural areas where human resources are readily available, while encouraging biodiversity and the sustainable restoration of soil as a living milieu.
1 UNESCO, in association with the United Nations Environment Programme (UNEP), the Food and Agricultural Organization (FAO) the International Cell Research Organization (ICRO) and other non-governmental organisations, has set up a world-wide network of specialised research and training institutions called MIRCENs (Microbial Resources Centres) to promote the preparation and use of cheap biological fertilisers
Some applications of biotechnologies1|
Diagnosis and therapy account for 68% of the biotechnology industry in the USA, 43.7% in Canada and about 43% in Europe. For example:
- recombinant drugs, such as human insulin, growth hormone, interferon, erythropoietin).
- recombinant diagnostic kits (eg. to test for HIV, or pregnancy)
- recombinant vaccines (eg. against Hepatitis B and AIDS)
- production of medicines by transgenic plants or animals (in milk or urine)
- genetically modified crops resistant to pests, viruses, drought, etc.
- genetically modified crops that ripen slowly during transport before display
- use of organic material to produce biodegradable plastics, fuel, fertiliser
- in vitro fertilisation of farm animals using selected sperm and eggs
- use of recombinant growth hormone to increase milk and meat production
- genetically modified crops with better nutritional qualities
- fish farming (aquaculture)
- seaweed farming to produce fatty acids, etc.
- production of adhesives from mussels and barnacles
- use of enzymes from thermophile bacteria (usually living in dark, sulphurous, hot environments in the deep sea) for waste removal, or in sequencing DNA
Use of micro-organisms
to produce proteins
- use of bacteria and yeasts to ferment petrol derivatives, whey, wood cellulose, etc.
- pollution fighting using enzymes or microbes (eg. oil spills)
- use of plants to remove contamination by heavy metals
- water treatment
- treatment of air pollution
- production of tree clones from tissue culture
- production of wood pulp for the paper industry
- production of energy from biomass
- biological sensors and switches for electronic processes
- conservation of endangered species using cloning
1 See Colwell, R.R. & Sasson, A. Biotechnology and development. In World Science Report 1996. UNESCO