e Courierw   m1       m                 ^H .            v    H            v^   "* ^i                             culture
A time to live...                                  Jumping for joy                  Sierra Leone is a country on the west ...
Editorial                                                                                             March 1987          ...
by Jacques C. Senez            The new                                        biotechnologies                            P...
Drawing shows in highly simplified form                                                                                   ...
obtained either from the male gametes, or           in regenerating somatic hybrid cells of sev¬                 Nitrogen ...
cent and its effect, which lasts for two years,                  visiae) and certain anaerobic bacteria, suchis equivalent...
Powerful protoplasts     Techniques for the cloning of plants are     now so refined that a single cell removed     from t...
33^                                                                        yj.                                            ...
ylotropha or Methyiococcus capsulatus) in             tein-rich microbial biomass and residual              is too low for...
by Bernard Dixon                                                                                         The gene         ...
has already greatly enhanced our specificity     pieces of DNA in this way, genetic engi¬         teria and gives the plan...
mation about the DNA sequences codingfor them. This knowledge may well lead tomethods of altering those sequences orintrod...
The use of genetic engineering in food                                                                                    ...
Tomatomation     Japans high-tech food factories                                                                          ...
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
Green revolution
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Green revolution
Green revolution
Green revolution
Green revolution
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Green revolution

  1. 1. e Courierw m1 m ^H . v H v^ "* ^i culture
  2. 2. A time to live... Jumping for joy Sierra Leone is a country on the west coast of Africa with a population of some 3,600,000. It takes its name ("Lion mountain") from that given by the Portuguese explorer Pedro da Sintra around 1460 to the peninsula which is the site of Freetown, the countrys capital. In 1787 a settlement for freed slaves was established on land where Freetown now stands. In 1961 Sierra Leone achieved independence, and ten years later became a republic. Some 65 per cent of the work force is occupied in agriculture, with rice as the main food crop. Sierra Leone is the worlds sixth largest producer of diamonds. Above, body bent back and almost obscuring the ball, a boy throws himself into a game of soccer in a Freetown street.52 Sierra Leone
  3. 3. Editorial March 1987 40th yearIn the 1960s and 1970s, the development of high-yield cereal varieties 4combined with the use of pesticides , irrigation and fertilizer brought a The new biotechnologiesGreen Revolution to some but not all parts of the Third World. This Promise and performance by Jacques C. Senezissue of the Unesco Courier, which is largely devoted to the application ofnew scientific techniques to agriculture, enquires into the extent to whichthe Green Revolution is likely to be followed by a "Biotechnological The Green RevolutionRevolution" which may help developing countries to solve some of their 13food production problems. Although the term biotechnology to denote the use of the biochemical The gene revolution by Bernard Dixonand genetic capacities of living organisms for practical purposes is fairly 17new, man has been engaged in "biotechnological" activities since veryearly times. Fermentation and the improvement of useful plant and Tomatomationanimal varieties by cross-breeding are but two examples. The new Japans high-tech food factories by Koichibara Hiroshibiotechnology, however, differs from these time-honoured practices in 20that it uses genetic engineering and techniques of fusing cells of differentorganisms to surmount previously impassable barriers between species. Hybrids for the year 2000Genetic engineering (or gene-splicing) , which involves the direct transfer by Raissa G. Butenko and Zlata B. Shaminaof genes "those tiny command posts of heredity that tell living cells 22whether they will become bacteria, toads or men" into the cells of Grains of hopedifferent species has been described as the "most powerful and awesome by Edward C. Wolfskill acquired by man since the splitting of the atom . " 24 In the first part of this issue we look closely at some of these new The rediscovery of traditionalbiotechnologies: how they work; how they are currently being used in agriculturedifferent parts of the world and to what effect; the latest trends in this 26field where changes occur quickly and possibilities are vast. While ourcontributors focus mainly on the direct applications of biotechnologies to Rusitec the cow Food for ruminationagriculture in the developing world, they also note present and potentialuses in energy production, human and animal medicine and the 27management of certain environmental problems. Rhizobium, the farmers Mr. Fixit The second part of the issue asks broader questions. How can the new A Unesco programme to promote biotechnology for developmentbiotechnologies be best harnessed to development in different social , by Edgar J. DaSilva, J. Freiré, A. Hillalieconomic and cultural contexts? Will they be a panacea or, contrariwise, and S.O. Keyaare they likely to aggravate existing disparities between developing 29countries and those of the technologically advanced world? The new A challenge for the developing worldbiotechnologies and especially those applied to plants, put great by Albert Sassonpossibilities into the hands of those who control them. How should this 34power best be exercised? How should access to the fruits of researchbased on plant genetic resources originating in the developing world be Glossaryequitably organized? 2 Unesco, which is engaged in worldwide efforts to strengthen rural A time to live...development through training in the biological and agrobiological SIERRA LEONE: Jumping for joysciences, in applied microbiology and in biotechnology (see article page27) , is closely interested in the above issues as part of its basiccommitment to promote the use of science and technology for the benefitof all humanity. The complex nature of the problems and some possibleapproaches and solutions are traced by Dr. Albert Sasson in the articlewhich forms the conclusion of this issue.Editor-in-chief: Edouard Glissant Cover: Photo © Periscoop, Paris Italian Turkish Macedonian A selection in Braille isThe Courier English French Hindi Urdu Serbo-Croat Finnish Swedish published quarterly in English,A window open on the world French, Spanish and Korean Spanish Tamil Catalan Slovene BasquePublished monthly in 32 languages Russian Hebrew Malaysian Chinese Thaiby Unesco German Persian Korean BulgarianThe United Nations Educational, Arabic Dutch Swahili GreekScientific and Cultural Organization ISSN 004 1-52787, Place dc Fontenoy, 75700 Paris. Japanese Portuguese Croato-Serb Sinhala N"3-1987-CPD-87-l-443 A
  4. 4. by Jacques C. Senez The new biotechnologies Promise and performanceSINCE the beginnings of civilization, hopes, some of which, such as the produc¬ sugar is another example of a social and man has been a biotechnologist, tak¬ tion of human insulin by bacteria recom- economic backlash due to biotechnology. ing advantage of the activities of bined in vitro, have already become reality. Due largely to the production of iso-glucosemicro-organisms of whose very existence he Today, these methods are on the verge of in the United States, this sugar price col¬was unaware, to produce foodstuffs and fer¬ finding new applications of considerable lapse has spelled ruin to a number of tropi¬mented drinks. Over the centuries, the economic and social importance in the field cal countries whose economies are based onpractices by which he did this gradually of agriculture. It would be wrong, however, sugar-cane.developed, in a makeshift, empirical fash¬ to think that the prospects for biotechnol¬ Fortunately, not all biotechnologyion, to attain a high degree of perfection. ogy are limited to the field of genetic engi¬ applications entail problems such as these.Yet biotechnology proper, in the sense of neering. Recent advances in fundamental However, there is a danger that some ofthe scientific use of biological principles for knowledge and techniques in the physiol¬ them will further increase rather thanpractical purposes, only emerged at the end ogy of cells, biochemistry, enzyme catalysis diminish Third World dependence on theof the last century with the birth of micro¬ and bioengineering are just as promising. richest and most scientifically advancedbiology and its early application to indus¬ It is generally thought that there is a great countries (see article page 29).trial fermentation processes. future for biotechnology in the developing Bearing this in mind, the developing Since the Second World War, biology has countries, particularly in its applications to countries must concentrate their efforts onmade prodigious progress. In just a few agriculture. These hopes are well founded, programmes which are both of direct inter¬years the basic mechanisms of life and but it should not be forgotten that progress est to them and which can be implementedheredity at the molecular level have been involves potential dangers against which all immediately within the limitations of theirunveiled, thus opening up limitless hori¬ possible preventive measures should be financial and economic resources. Manyzons. Some of these prospects, in particular taken. such opportunities are open to them in agri¬that of the development of genetic engi¬ The first major achievement of agri¬ culture in which two avenues in particularneering (see article page 13) with its con¬ cultural biotechnology was the "Green beckon: that of primary production, wherenotations of man the creator, captured the Revolution", whose ambitious objectives there are possibilities in the field of plantimagination and fired the enthusiasm of the have been largely achieved (see box page improvement and nitrogen fixation, andgeneral public. 7). Thanks to the Green Revolution India, that of bioconversion of agricultural prod¬ The transfer of genetic material between Bangladesh and several other Third World ucts and wastes into energy and foodorganisms as widely different as bacteria, countries have achieved self-sufficiency in resources.plants, animals and man gave rise to great food. This was a true success, but it brought in its train a number of unforeseen social New techniques consequences. The farming of high-yield for better plants cereals requires considerable investment in fertilizers, pesticides and irrigation which Plant improvement by the traditional many small farmers were unable to make. methods of selection and cross-breeding is As a result many of them had their fields as old as agriculture itself. Thanks to recent taken over by the large landowners and advances in knowledge of the genetics and were forced to move to the cities and swell physiology of plants these methods have the ranks of the sub-proletariat. been refined and will long continue to pro¬ The recent collapse in the world price of duce very important results. During the past thirty years, for example, the yield of maize has increased from 12 to 62 quintals per hectare, while that of wheat has grown Egyptian bakers and brewers of 3,500 on average by one quintal per hectare per years ago are shown at work in this scene year. Similar progress has been made with from a Theban tomb. "Biotechnological" processes such as microbial fermenta¬ rice, the second most important of the great tions have been used for thousands of cereals in worldwide use. Today, the Inter¬ years to produce beverages and foods national Rice Research Institute (IRRI), such as beer and cheese. < set up in the Philippines in 1962, has a col¬ © Drawing taken from A History of Technology lection of 60,000 varieties of rice (see the © Oxford University Press Unesco Courier, December 1984).
  5. 5. Drawing shows in highly simplified form one of the techniques used in modem biotechnology for experimentation under controlled conditions with plant cells, tis¬ sues and organs and for vegetative (i.e. non-sexual) propagation of plants in ster¬ ile laboratory conditions. The sterilized plant material which is cultured in the nut¬ rient medium may be a meristem (see drawing at bottom of page), or some other piece of plant tissue (see photo story pages 8-9), or a protoplast, a plant cell whose outer walls have been removedplant culture of colony of regeneration mini- greenhouse (see page 10). From this organ, tissue, or meristem or cells of plantlets cells protoplast, a proliferating clump of dis¬ multiplication organized tissue called a callus can be in sterile obtained. From this it is possible to re¬ conditions generate whole intact plants, and to pro¬ duce many genetically identical copies, known as clones, in a relatively short time. A one-cubic-centimetre culture may con¬ In addition to improving yield, the main culture of the meristem or other plant tain one million cells each carrying thepurpose of selection is to obtain new vari¬ tissues. Meristem is the name given to a potential of becoming an entire new plant.eties which are resistant to parasites and to grouping of embryonic cells situated at the By selecting cells with certain properties, the process of breeding new varieties ofbacterial and viral diseases. In recent years tip of the plant stem (see drawing below). disease-resistant, stress-tolerant crops,a number of new techniques have made Cultivated in aseptic conditions on a solid, trees or flowers can be greatlytheir appearance, some of which are nutritive culture medium, these cells accelerated.already in use while others are still at the proliferate producing a callus which can belaboratory stage. One of their main aims is divided and reproduced many times.to reduce considerably the time needed for Treated with plant hormones (auxins,a new variety to be put on the market and cytokins and gibberelins), the calluses diffe¬ months, 2,000 million identical tubers,brought into large-scale cultivation. Using rentiate into plantlets having all the prop¬ spread over an area of 40 hectares, wereclassic methods the lead time required to erties of the original plant. obtained from a single potato tuber derivedachieve this is of the order of ten years, By this means, in a period of eight from a meristem, that is a rate of propaga¬whereas, given the capacity for adaptation tion 100,000 times greater than that of sex¬of the phytopathogenic agents (the bacte¬ ual reproduction. A further advantage isria, viruses, etc., that cause plant disease), that plants obtained from meristems arethe useful life of a new variety is estimated The apical meristem is a tiny mass of cells free of pathogenic contaminants, in particu¬ where growth takes place at the tip of ato be a mere five years. lar of viruses, which means that it is possible plant stem. It plays a particularly important Another advantage of certain recently role in plant propagation because it re¬ to regenerate stock threatened with extinc¬evolved techniques is that they make it pos¬ mains healthy even when the rest of the tion due to diseases that cannot be treatedsible to cross-breed species that are too far plant is infected with a virus. In vitro cul¬ in any other way.apart for normal sexual reproduction, thus ture of the meristem of a diseased speci¬ Tropical agriculture has much to gain men makes it possible to generate a new,opening the way for the creation of entirely from micro-propagation. For example, a healthy plant, and allows the rapid produc¬new plant varieties. single oil palm regenerated from a fragment tion of virus-free planting materials. Be¬ The first major successes were achieved low, sectional drawing of a plant bud of leaf tissue could, within a year, supplyby means of vegetative hybridization of shows the apical meristem at centre, pro¬ 500,000 identical, filariosis-resistant plantscereal seedlings. This method, which con¬ tected by enfolding leaf shoots. Meristem producing up to 6 tonnes of oil per hectaresists of cross-breeding between plants by culture calls for particular care in the per year, that is six to thirty times more than choice of culture conditions and nutritivethe elimination of self-fertilization, is com¬ the principal oil-producing plants (sun¬ media.paratively easy in the case of allogamous flower, soya, peanut). This same techniquecereals, such as maize, in which the male is now being applied to the propagation of leaf shootsorgans are separated from the female new varieties of coconut palms.organs and can thus be manually eliminated Another technique which holds greatbefore fertilization has taken place. It is promise for the future is the in vitro produc¬more difficult with autogamous plants, such tion of haploid plants (plants whose cellsas wheat, tomatoes, soya and lupin, in contain a single set of chromosomes). Tra¬which the male and the female organs are ditional methods of selection are madecontained in close proximity within the more time-consuming and complicatedflower. Today, this difficulty has been over¬ because of the diploid nature of vegetativecome by the discovery of chemical com¬ plants, that is to say, because the cells ofpounds which render the pollen sterile. which they consist contain a double set of Many varieties of hybrid cereals and chromosomes, one coming from each pa¬other plants are now on the market. Gener¬ rent. As a result, some so-called "recessive"ally speaking, fields should be sown with characteristics carried by a chromosomefirst generation hybrid seed. Hybrid seed may be masked by a dominant homologoususually tends to degenerate and must be chromosome and its presence may onlyrenewed annually. At all events, the world be revealed, through the operation ofmarket for hybrid seed is growing rapidly Mendelian segregation, after severaland, according to a recent estimate, will generations.attain a value of $20,000 million by the year This, of course, slows down the work of2000. the person undertaking the selection. The Other techniques now being developed recent emergence of a technique somewhatare more distant in prospect yet just as similar to micro-propagation has made itpromising. One of these is in vitro vegetative possible to overcome this difficulty. Thispropagation, or micro-propagation, by the technique enables a complete plant to be
  6. 6. obtained either from the male gametes, or in regenerating somatic hybrid cells of sev¬ Nitrogen fixationreproductive cells (androgenesis), or from eral plants of agricultural interest such asthe female gametes (gynogenesis). Like the rapeseed, chicory and potato. On the other Through its World Network of Micro¬gametes from which they are derived, these hand, attempts to do the same with sun¬ biological Resources Centres (MIRCENs),plants are haploid. Since they have only one flower, cereals and legumes have so far one of whose priority programmes isset of chromosomes, their genetic charac¬ failed. Nevertheless, there is hope that devoted to the question of nitrogen fixa¬teristics, whether recessive or dominant, present difficulties will soon be overcome, tion, Unesco is contributing actively toare immediately evident to the person mak¬ at least in obtaining hybrids of varieties of another field of biotechnology that is rich ining the selection. Haploid plants are usually the same species. promise (see article page 27).infertile, but by treating them with col¬ The great advantage of somatic hybrid¬ The nif genes, which are coded for thechicine, which induces a doubling of the ization is that it makes it possible to transfer fixation of nitrogen, have now been identi¬chromosomes, a fertile plant is obtained not only the genetic characteristics borne by fied and their structure is on the point ofwith two sets of identical chromosomes and the chromosomes of the nucleus, but also being fully mapped out. Furthermore, thesewith phenotypically stable characteristics. those of the specialized parts of the cell genes have been transmitted to non-Another technique used in gynogenesis is to contained in the cytoplasm (the "liquid" nitrogen-fixing organisms such as Proteusfertilize the ovule with irradiated pollen. portion of a cell surrounding the nucleus) vulgaris, Agrobacterium tumefaciens and In China, new varieties of rice obtained such as mitochondria and chloroplasts. Escherichia coli. In principle there is noby androgenesis are being cultivated on sev¬ These latter are the key to processes and reason why they should not also be trans¬eral millions of hectares of land. Laboratory properties of great importance such as ferred to higher plants and importantexperiments in gynogenesis are also now photosynthesis, the assimilation of carbon results in this direction can be expectedbeing undertaken on barley, rice, wheat, dioxide, male sterility and resistance to soon. However, the creation of nitrogen-maize, sugar-beet and other species. herbicides, diseases and drought. fixing cereals is a distant prospect still in the Somatic hybridization has paved the way realm of science fiction. High hopes are also being placed in soma¬tic hybridization, a technique which consists for the newly emerging discipline of plant With regard to plants other than theof fusing two cells whose cell walls have genetic engineering which is concerned with legumes, attention is now concentrated onpreviously been removed by enzymatic the implantation of specific genes", whether nitrogen fixation by bacteria and fungitreatment. Using this technique scientists of vegetal or other origin, into the genetic which invade their roots either on the roothave succeeded in fusing plant cells not only make-up of a plant (see article page 13). surface or by entering their tissue wherewith other plant cells but also with animal Using these new techniques the nutritional they form nitrogen-fixing nodules. Theseand even human cells. In most cases, value of the haricot bean, for example, has studies have not yet reached the molecularhowever, the chromosomes of one of the been improved by the transfer of a gene biology or the genetic engineering stage,fused cells are quickly eliminated and it has from the Brazil nut. but they hold out much promise for tropicalonly been possible to obtain complete, In Europe, Japan and the United States forestry, sand dune stabilization and thestable hybrid cells from the fusion of cells of America, a number of large multina¬ fight against desertification.from very closely related species. Further¬ tional companies are showing keen interest Finally, mention should be made of stud¬more, even when stable stock has been in these new techniques of plant improve¬ ies being made in the Philippines and Sene¬obtained, it has proved difficult to regener¬ ment with a view to competing for the world gal on the use of the water fern Azolla pin-ate a complete plant from such fused cells. market. Nevertheless, this branch of bio¬ nata as a biological fertilizer in rice fieldsThe first success achieved was the regenera¬ technology also offers great opportunities (seethe Unesco Courier, December 1984).tion of the pomato, a cross between a potato for the developing countries. These new In symbiotic association with the blue-greenand a tomato. However, the plant is sterile techniques, which they have already algaAnabaena this water fern has the abilityand remains no more than a laboratory acquired or can rapidly master, will enable to fix atmospheric nitrogen. Ploughed intocuriosity. them to adapt their agricultural production the soil between harvests, this "green fertil¬ More recently scientists have succeeded to meet local conditions and requirements. izer" can increase the crop by over 50 perr The Green Revolution RESEARCH into the selection of new even better adapted and which gave a better end of the 1970s. In the Punjab, farm re¬ high-yield cereal varieties began after yield. In addition to wheat and rice, this venues doubled in 1972, six years after the the Second World War. Wheat and research also concerned millet and sorghum, introduction of new cereal varieties.rice varieties were selected In Mexico and the triticale, maize and several leguminous plant In some regions of Asia where waterPhilippines respectively, then during the species. resources permitted, the shortening of the1960s the new strains were used in other In just over a decade, more than half the growing period of new rice varieties allowedparts of the world, and it was later established surface of corn-growing land and one-third of two or three crops to be harvested per year.that they had contributed to a significant that of rlceland in developing countries had The prime beneficiaries of the "Greenincrease in agricultural yields. been sown with high-yield cereal varieties. Revolution" were the wealthier farmers of In the mid-1960s, following the introduction When the latter are irrigated, and receive ade¬ some developing countries. The countries ofof these high-yield varieties Into several coun¬ quate supplies of fertilizer and weed-killer, the Africa south of the Sahara were scarcelytries of Asia and Latin America, the expres¬ yield is two or three times higher than that of affected; only Kenya and Zimbabwe in¬sion "Green Revolution" was coined to traditional varieties. creased the area of land on which new vari¬describe the various efforts made to increase The new varieties of wheat were introduced eties of maize were grown. The wheat and riceagricultural production in the developing to India in 1966 and Indian wheat production varieties were not introduced at the samecountries by means of these new varieties, had doubled by 1970-1971, when it reached pace as in Asia where the development ofespecially wheat and rice. The cultivation of 23.4 million tonnes. As a result of local efforts irrigation, adequate fertilizer supplies, and thethese crops required the use of pesticides and to improve varieties and a more widespread marketing system of farm produce played anIrrigation in addition to fertilization and sound use of selected seeds, output reached 33 mil¬ important role in the success of the "Greenagricultural practices. Cross-breeding be¬ lion tonnes in 1978-1980. From being the Revolution."tween these varieties and hardy local breeds worlds second largest cereal importer in Source: Oue//es biotechnologies pour les pays en développe¬made it possible to obtain cultivars that were 1966, India had become self-sufficient by the ment? by A. Sasson, Biofutur/Unesco, Paris. 1986
  7. 7. cent and its effect, which lasts for two years, visiae) and certain anaerobic bacteria, suchis equivalent to the use of 60 kilograms of as Zymomonas mobilis, convert the sugarsnitrogen fertilizer per hectare. into ethanol with an average yield of 47 per cent, by weight. Several suitable raw mat¬ The cloning erials are available in considerable quan¬ Energy from waste tities at a low price. However, from the of the oil palmBiotechnologys contribution in the field of economic point of view there is one impor¬new energy sources is today arousing great tant drawback: the ethanol has an inhibitinginterest for two reasons: the foreseeable The oil palm (Elaeis guineensisj is culti¬ effect on the micro-organisms that produce vated as a source of oil in the humid tropic¬exhaustion of our supplies of fossil energy it and the maximum concentration in the al zones of Africa, the Americas and(oil and coal), and the world energy crisis reactors cannot exceed 8 to 10 per cent. As a South-east Asia, where oil palm planta¬which, since 1973, has weighed heavily on tions cover several million hectares. result, the distillation of bio-ethanol and itsthe economies of all countries, but par¬ Selection cycles to produce higher-yield¬ complete dehydration, which is essential to ing varieties through sexual reproductionticularly on those of the countries of the its use as a fuel, are costly operations con¬ were very long, and their results were onlyThird World. stituting about 60 per cent of the cost perceptible after 15 or 20 years. In the One achievement, which has already price. 1970s, attempts were thus made to perfectbeen developed on a large scale in a number In Brazil, ethanol fuel is produced from in vitro propagation of the oil palm usingof countries, is the production of biogas sugar-cane on a large scale. At present pro¬ Photo © IRHO-CIRAD/ORSTOM, Parisfrom cellulose and animal and human duction is running at 8.4 million tonneswastes. This is based on the anaerobic which in energy terms is equivalent to 5.6digestion of cellulose and nitrogenous million tonnes of super-grade petrol. Inorganic matter by mixed populations of agricultural terms the yield is 4.7 tonnes permicrobes consisting of bacteria that break hectare of sugar-cane per year.down cellulose into organic acids and other At present, the cost price of bio-ethanolbacteria that convert these organic acids exceeds that of petrol by $380 per tonne. Ininto methane. Brazil, however, the economic motivation Experience acquired in India indicates for producing bio-ethanol is to improve thethat the manure from ten cows would balance of payments by reducing imports ofprovide a daily yield of 1.8 cubic metres of petrol and to provide an outlet for the sugarbiogas, which is the equivalent of 1.3 litres industry which has been badly hit by the fallof petrol, enough to cook the food for four in the price of sugar on the world market.people or operate a hundred candlepower Bio-ethanol is arousing great interestlamp for fourteen hours. What is more, the elsewhere for similar reasons. In the Unitedresidue constitutes an excellent fertilizer of States, "Biohol", an automobile fuel con¬a quality far superior to the original taining 10 per cent ethanol produced frommanure. maize, has been on the market for several A million of these cheap and simple bio- years. In Western Europe it is planned togas digesters are in service in India and produce 3.4 million tonnes of bio-ethanolmore than seven million are in use in China. annually. The aim of this project is to makeProduction of biogas on farms can be use of European surpluses of wheat andexpected to spread soon to other agri¬ sugar-beet. There is also an ecologicalcultural areas in which other forms of motivation. Added to automobile petrol inenergy are not available. From the ecologi¬ a proportion of 5 per cent, ethanol cancal viewpoint, biogas has the great advan¬ replace the tetraethyl lead anti-knock addi¬tage that it can replace firewood, thus tive now used in petrol, but shortly to becontributing to the struggle against banned because of its toxic effects.deforestation and desertification. Biogas production is also increasing in Bridging the protein gapthe industrialized countries as well as inlarge towns and heavily populated rural Generally speaking, proteins, or the lack of tissue culture, and since 1981 oil palmareas in general. The main economic gain them , constitute the major nutritional prob¬ plantlets have been produced on a semi-here is that the treatment of waste water lem facing the developing countries. Statis¬ industrial scale at the La Mé research sta¬and the handling of agro-industrial wastes tics published by the Food and Agriculture tion in the Ivory Coast (1) using a cloningand the animal waste from intensive stock- Organization of the United Nations technique developed by British and French researchers in the 1970s. Photosrearing can be turned to advantage by the (FAO), show that average total protein show some of the stages in the cloningproduction of methane. Already several consumption per head of population in the process. Fragments of very young leavesurban water treatment plants in Europe developing countries is only half that of the are carefully removed from the tip of a treemeet all their energy requirements by the rich countries. The difference is even more (2) and placed in a nutrient medium whereproduction of biogas. marked with regard to protein of animal calluses develop (3). After going through a origin, average consumption of which in the second and then a third culture medium the calluses evolve into "embryoids" (4) Green gasoline developing countries is 13 grams per comparable to the embryos obtained by day a mere 22 per cent of that in rich coun¬ sexual reproduction. They multiply spon¬The production of liquid fuels, in particular tries and this falls to 4 grams per day in taneously, and this multiplication is fos¬ethanol, is another major contribution of the poorest regions of Africa and Asia. tered in a fourth culture medium. A fifthbiotechnology in the field of new energy In the developing countries a great vari¬ culture makes it possible for the embryossources. A large number of agricultural raw ety of agricultural products and wastes lend to develop into young leaved plantlets (5). The shoots are transferred to a sixthmaterials can be used for the production of themselves to the production of single-cell medium in which roots are induced (6),ethanol by fermentation, including the edible protein. These include, in particular, while in a seventh medium entire youngsucrose in sugar-cane, sugar-beet and ligno-cellulosic matter which is available in plants are obtained for planting in soil (7).molasses, the starch from cereals, manioc large quantities at a low price. According It takes about 3 months to obtain a 12 cmand potatoes, and the inulin from Jerusalem to the United Nations Environment shoot from an embryoid.artichokes. Programme (UNEP), the world crop of Brewers yeast (Saccharomyces cere- cereals produces annually 1,700 million L8
  8. 8. Powerful protoplasts Techniques for the cloning of plants are now so refined that a single cell removed from the body of a plant can be cultured in the laboratory and then induced to re¬ generate a complete individual plant. Drawings at left and below are a schematic representation of the cloning process used by Prof. James F. Shepard and his colleagues at Kansas State University to regenerate a complete potato plant from protoplasts (living cells stripped of their outer wall) prepared from leaf cells. Small terminal leaves are first removed from a young potato plant (1). The leaves are placed in a solution containing a combina¬ tion of enzymes capable of dissolving the cell wall to produce protoplasts (2). The solution also causes the protoplasts to withdraw from the cell wall and to become spherical, thereby protecting the proto¬ plasm during the disintegration of the walls (3). The protoplasts are next grown in a culture medium (4) where they divide and begin to synthesize new cell walls (5). After 2 weeks of culture in these con¬ ditions, each protoplast gives rise to a clump of undifferentiated cells or micro- calluses (6). These microcalluses develop into full-size calluses in another culture medium (7) and their cells begin to dif¬ ferentiate, forming a primordial shoot (8). The shoot develops into a small plant with roots in a third culture medium and is then tonnes of straw, to which can be added planted in soil (9). Under appropriate con¬ some 127 million tonnes of bagasse from ditions protoplasts from 2 different plants sugar-cane and pulp from sugar-beet. At can be fused to form a cell possessing present, the main obstacle to their use for genes of plants which cannot be crossed using classic methods. The fused proto¬ the production of proteins is the lack of plasts of some species can be grown into sufficiently active microbial strains for this plants in a process known as somatic specific purpose. Recently achieved labora¬ hybridization. tory results suggest that this problem will soon be overcome. Cuba is, at present, the only developing country producing single-cell edible protein from agricultural raw material. Eighty thousand tonnes of forage yeasts for use as animal feed are produced annually from sugar-cane molasses. The Cuban example will probably soon be followed in other countries, such as India, where molasses is also available at a low price.10
  9. 9. 33^ yj. © For a long time now Western Europe has Born in Europe some thirty years ago, this Protein enrichment by fermentation is a branch of biotechnology that could helpbeen producing single-cell edible protein branch of biotechnology has developed to some developing countries increase theirfrom various agro-industrial wastes such as the point where there are factories with a protein resources. Microbial fermentationlacto-serum (80,000 tonnes per year) and production capacity of 100,000 tonnes per of such crops as manioc, which containthe sulphite liquors used in paper-making year. much starch and relatively little protein,(25,000 tonnes per year). As with biogas, The oil treatment processes make use of yields a product with a substantially high¬the main economic incentive for this pro¬ yeast micro-organisms (Candida lipolytica er protein content. The banana is a fruit toduction is the elimination of the cost of which this process could be applied, and and Candida tropicalis) which are derived several banana-producing countries arehandling potentially polluting wastes. It is from diesel oil or from paraffin, previously investigating the possibility of using into be expected that the same will happen extracted from crude oil, and having a yield this way the high proportion of fruit re¬soon in the developing countries where of 100 per cent by weight. In the case of jected for export and usually wasted.increasing industrialization is making pro¬ methanol, chemically derived from natural Above, harvesting bananas in Martinique.tection of the environment an ever more gas, the biomass produced is that of bacteriaurgent necessity. such as Methylophilus methylotropha whose One of microbiologys most promising yield on this substrate is of the order of 50contributions to the problem of edible pro¬ per cent, by weight. The methanol treat¬teins is their production on an industrial ment processes make use of specific meth¬scale from oil, methanol and natural gas. ane-eating bacteria (Pseudomonas meth- 8After J.F. Shepard in Scientific American, New York, 1982 11
  10. 10. ylotropha or Methyiococcus capsulatus) in tein-rich microbial biomass and residual is too low for it to be used as animal feed, isconjunction with other species whose task is agricultural raw material whose nutritional a complete write-off. For a number of Cen¬to prevent the inhibition of the bacteria by value is thus enriched. This relatively sim¬ tral American countries which export sev¬intermediate accumulation of methanol. ple technology has the advantage that it can eral million tonnes of bananas annually, the Very large-scale experiments with the be used both on a large industrial scale and prospect of recuperating wastage on thisproducts thus obtained from oil and meth¬ in small, inexpensive production units scale by use of the fermentation process isanol have demonstrated conclusively their located in rural communities. This means clearly of the greatest interest and thishigh nutritional value and complete that high-quality edible protein can be pro¬ possibility is being actively investigated ininnocuousness. Up till now, these edible duced from a wide range of agricultural raw Mexico, Guatemala and the West Indies.proteins have been marketed exclusively as materials that are too costly or available Finally, the third major contribution thatanimal feed, but preliminary studies have locally only in quantities too small for use biotechnology has to offer to the solution ofshown that there is nothing to prevent their with standard single-cell edible protein pro¬ the world problem of edible protein is thebeing used directly as food for humans. duction methods. industrial production of amino acids as a Following the first oil crisis of 1973, pro¬ In all the tropical regions, manioc (also complement to plant proteins. Many suchduction of single-cell edible protein from oil known as cassava) is the chief agricultural proteins, in fact, are only of limited nutri¬and from methanol slowed down in West¬ raw material potentially available for pro¬ tional value because of their lack of certainern Europe due to the increased cost of the tein enrichment. Cultivated throughout essential amino acids which man and otherraw material. In Eastern Europe and in the Africa, in Asia and Latin America, the mono-gastric animals (including pigs,USSR, however, it has developed consider¬ world production of manioc is of the order young ruminants and poultry) are unable toably and now amounts to some 3 million of 100 million tonnes. Very rich in starch, synthesize and therefore must find in theirtonnes per year. but containing practically no protein, man¬ food. This is the case in particular of lysine, This branch of biotechnology is of ioc is used above all as a supplementary which is the amino acid in which cereals areobvious interest to those developing coun¬ energy food. Furthermore, although under most notably deficient and lack of which istries that are producers of oil and natural good conditions it can yield 50 tonnes per the main cause of malnutrition in the Thirdgas, since these raw materials are available hectare and over, it is normally only culti¬ World. Almost all the amino acids used as ato them in large quantities at prices well vated on small patches of land using rudi¬ complement to plant proteins are obtainedbelow the world market price. The Organi¬ mentary methods with low productivity. by fermentation using hyper-productivezation of Arab Petroleum Exporting Coun¬ At present, the only country in which bacterial strains selected genetically.tries, for example, proposes as a first step to manioc cultivation has been developed Apart from methionine, which isproduce 100,000 tonnes of single-cell edible rationally is Thailand, which exports 7.5 basically intended for use in animal feed,protein a year, either from oil or from meth¬ million tonnes of manioc root to the Euro¬ lysine is the only amino acid produced inanol, and it estimates the potential market pean Community each year. large quantities (40,000 tonnes per year). Itin the Middle East and in the Maghreb at Starting with dried manioc with an initial has been estimated that the world deficit inmore than a million tonnes. It should be content of 90 per cent starch and less than 1 lysine, most marked in Africa and the Farpointed out that this amount of protein per cent protein, fermentation with an East, is 136,000 tonnes for human food andcould be obtained from 0.1 per cent of their amylolytic mould (Aspergillus hennebergii) three times that figure for animaltotal oil production. yields a product containing 20 per cent well- foodstuffs. As things stand at present, the Protein enrichment of foodstuffs by fer¬ balanced proteins and 20 to 25 per cent cost price of lysine is still too high to ensurementation is another promising prospect. residual sugars. In this way manioc can satisfaction of Third World needs and toApplication of modern biotechnological provide nearly 2 tonnes of protein per hec¬ compete with soya in animal feed. The sit¬methods to this practice, which is tradi¬ tare, that is, three times more than can be uation is the same for other amino acids, intional in Africa and the Far East, seems set obtained from the cultivation of soya or particular threonine and tryptophan,fair to provide the developing countries other leguminous plants. which, after lysine, are the chief elementswith a substantial increase in their protein The banana too is a raw material with a lacking in plant proteins. However, it isresources for human and animal consump¬ bright future. In the collection centres of reasonable to assume that, thanks totion. exporting countries, 20 to 30 per cent of the genetic engineering, substantial progress The end product of this fermentation pro¬ fruit gathered is rejected. This rejected will soon be made.cess is a directly consumable mixture of pro fruit, whose protein content at 1.1 per cent JACQUES C. SENEZ, French biologist and uni¬ versity teacher, is a former Secretary-General of the Unesco-sponsored International Cell Re¬ search Organization (ICRO) and a consultant member of the Protein Advisory Group of the United Nations. A past Secretary-General of the International Union of Microbiological Societies (IUMS), he is the author of a number of studies on microbiology and bacterial biochemistry. In the late 1960s he initiated the production of Single Cell Protein (SCP) from petroleum. 2 Many developing countries are engaged in I programmes to harness the techniques of e biotechnology for national development. § Left, fermenters of a Cuban factory pro- $ ducing single-cell edible protein from © molasses. The installation produces some % 40 tonnes of protein a day for use as anim- £ a/ feed.12
  11. 11. by Bernard Dixon The gene revolution GIVEN the mixture of benefits and which they are part. The astronomically problems spawned by the first long DNA molecule can be subdivided into Green Revolution two decades regions genes which determine particu¬ lar characteristics. Recombinant DNA is ago (see box page 7) , it is not surprising that both optimism and apprehension surround the name given to the product when a piece the application of genetic engineering now of DNA from one organism is combined to agriculture tomorrow. Mixed reactions artificially with that from another. are appropriate, because those develop¬ Genetic manipulation of this sort is the ments focused upon so-called recombi¬ basis for the boom that has occurred during nant DNA are destined to have even the past decade in biotechnology. Such more far-reaching effects than the tech¬ activities were, of course, possible pre¬ niques deployed in the first revolution. viously. Some, like the art of fermentingPhoto above shows the distinctive knot¬ sugar to make alcoholic drinks, are almost Todays new wizardry could undoubtedlylike growths or nodules which form on the as ancient as Man himself. Others, includ¬ transform agriculture throughout theroots ol legumes (plants of the pea family) world. At the same time, its precision in ing the first mass production of antibiotics,when they are infected by certain bacteria.These bacteria, known as rhizobia, take modifying living cells offers a stern chal¬ were developed earlier this century. But allnitrogen from the air and change it into lenge to our prudence and wisdom. of these processes were based on organismsforms the plants can use. One important At the centre of the stage is deoxy¬ as they occur in nature albeit with other,aim of research in biotechnology is to ex¬ equally natural, methods being used to ribonucleic acid (DNA), the material whichtend this process of nitrogen fixation to carries in coded form the hereditary instruc¬ select high-yielding strains.other crops by incorporating nitrogen-fix¬ tions responsible for the behaviour of cells The arrival of recombinant DNA, how¬ing genes into their genetic heritage. Thegoal is proving difficult to attain. and the plants, animals or microbes of ever, has altered the rules profoundly. It 13
  12. 12. has already greatly enhanced our specificity pieces of DNA in this way, genetic engi¬ teria and gives the plants the capacity toand power in tailoring living organisms for neers are beginning to create pedigree produce a toxin that is lethal to insects. Thebeneficial purposes. In future, it will extend microbes for a wide range of new purposes inbuilt insecticide makes the plants resistantour range of options much further. in agriculture, medicine and industry. to insect attack and does not, of course, The breakthroughs which have led to this Although genetic manipulation is taking have to be applied repeatedly. Some plantshistoric watershed in the fabrication of longer to perfect in plants, several tech¬ can mobilize defences against virus infec¬novel plants and microbes happened during niques are now emerging. The most useful tion through a process analogous to immu¬the early 1970s. The key discoveries were so far is based on Agrobacterium tumefa- nization in animals, and this suggestsmade by molecular biologists who learned ciens, a bacterium that causes crown galls another route for genetic alteration. Incor¬how to splice into bacteria genes which they on many flowering plants. It contains a poration of one virus gene into tobacco hashad taken from other bacteria, and even tumour-inducing (Ti) plasmid which is helped to protect this plant against subse¬from totally unrelated animal or plant cells. responsible for triggering the disorderly quent inoculation with the entire virus.They first found out how to locate the par¬ growth that appears as ugly galls. Genetic Another development concernsticular gene they wanted among the count¬ engineers have learned how to delete the Ti weeds a major limitation on crop hus¬less numbers on the DNA of one organism. plasmids tumour-inducing genes and use it bandry in most countries. Although weedsThen they used natural catalysts called as a vector with which to carry new genes can be combatted using selective her¬enzymes to cut out that gene and "stitch" it into plants. bicides, these often impair the growth of theinto a vector. This is usually a virus or a A serious drawback so far is that while A. crop too. It is now possible, however, toplasmid (a piece of DNA that replicates tumefaciens infects potatoes, tomatoes, and introduce resistance genes into tobacco andindependently from the nucleus, the main many forest trees, it does not normally petunia. One such manipulation results inrepository of DNA). The vector became a attack the monocotyledons such as cereals, the synthesis of enzymes in the plant thatvehicle for ferrying the selected DNA frag¬ which are prime targets for genetic im¬ are no longer sensitive to the inhibitoryment into the recipient. Once inside its new provement. Progress is being made, action of the herbicide glyphosate. Com¬host, the foreign gene divided as the cell however, and recent research indicates that mercial companies now plan to market adivided leading to a clone of cells, each rice in particular can be manipulated using package containing both herbicide andcontaining exact copies of that gene. the Ti plasmid. Alternative vectors and resistance seed. Because the enzymes used for genetic other methods of transferring genes are also Some 70 per cent of the worlds intake ofengineering are highly specific, genes can being developed. One exciting possibility is dietary protein consists of cereal grains andbe excised from one organism and placed in to use an electric current to promote the seeds of legumes. On their own, neitheranother with extraordinary precision. Such incorporation of foreign DNA. This works cereals nor legumes can provide a balancedmanipulations contrast sharply with the with maize cells, though scientists still have diet for human consumption, because themuch less predictable gene transfers that to persuade the cells to develop into whole "storage proteins" they each contain areoccur in nature. They also make it possible plants. deficient in one or more amino acids. Now,to splice genes that would be unlikely to One gene that has been transferred into added to analyses of the proteins in bothcome together naturally. By mobilizing tobacco by A. tumefaciens comes from bac cereals and legumes, we have precise infor- How to recombine DNA Drawing shows how a micro-organism (in this case a bacterium) is manipulated to make it synthesize a desired substance. (1) A bacterium contains a plasmid, which is a circular piece of DNA. This plasmid is isolated (2) and, with the help of a restriction enzyme, opened in a precise spot (3). Meanwhile, with the help of other restriction enzymes, the gene for synthesis of the desired substance is isolated from the DNA of another organism (4). Still using enzymes, this gene is grafted onto the previously opened plasmid (5). The plasmid is re-introduced into a bacterium (6). The manipulated bacteria are put into a culture, where they synthesize the desired substance. (7) o ó14
  13. 13. mation about the DNA sequences codingfor them. This knowledge may well lead tomethods of altering those sequences orintroducing new genes that code for a morebalanced spectrum of amino acids. The worlds energy and food supplies restupon the ability of green plants to convertatmospheric carbon dioxide into carbo¬hydrates, fats and proteins, using light fromthe sun. Unfortunately, the mechanism bywhich they consume carbon dioxide is inef¬ficient in those plants, such as wheat, barleyand potatoes, that are cultivated in tem¬perate climes. Oxygen in the atmosphereinterferes with the first enzyme involved inthe assimilation of carbon dioxide. Consid¬erable efforts are now being made to alterthe DNA sequence of the gene coding forthis enzyme, to prevent the deleteriousaction of oxygen. Other researchers are try¬ing to introduce into temperate zoneplants certain genes taken from maize,which has a more efficient mechanism ofcarbon dioxide uptake. In nature thismechanism appears to operate only athigher temperatures, but there are hopes of"switching it on" in cooler areas. Another atmospheric gas is the subject ofparallel efforts to make plants more effi¬cient. Nitrogen constitutes 80 per cent ofthe air, yet plants cannot use the gasdirectly. Hence the heavy dependence ofmodern intensive agriculture on fertil¬izers nitrate, ammonia or urea syn¬thesized by the chemical industry. Naturalnitrogen fixation depends in part onrhizobia, bacteria that live symbioticallywith legumes such as peas, beans andclover. The bacteria grow on sugarsprovided by the plant, and are maintainedin characteristic nodules on the plant. Therethey convert nitrogen directly intoammonia, leading in turn to the synthesis ofplant proteins. Molecular biologists have now isolatedand characterized several of the genesrequired for nitrogen fixation. They havefound, however, that many more bacterialand plant genes are involved than they first fixation. Drought resistance which depends A key area in biotechnology research isimagined. This makes the manipulation of on a reduced area of leaf surface, for exam¬ concerned with the development of tech¬those genes correspondingly more difficult. ple, may be caused by the interaction of niques for isolating genes of one plant andSo it will be some years before we can enjoy multiple genes. introducing them into another as a means of endowing the host plant with new char¬the cost and energy savings that should Microbes that contribute to healthy plant acteristics such as higher protein contentaccrue by providing crops such as wheat and growth are also on the drawing board for or resistance to pests. One promisingmaize with the ability to fix their own genetic engineering. One possibility being technique for transferring genes usesnitrogen. examined is the production and deliberate Plasmids (small pieces of genetic material) Drought and high temperatures are release of rhizobia that fix nitrogen more from a bacterium which causes tumourunwelcome to all plants, despite being bet¬ efficiently than natural strains. Other bacte¬ growths when it infects certain plants, above. It is possible to delete the plasmidster tolerated by varieties that have evolved ria capable of forming nitrogen-fixing part¬ tumour-inducing genes and use the plas¬in such environments. Desiccated soils also nerships with wheat and maize are also mid to ferry new "useful" genes intooften contain high levels of salts and metal¬ being considered. A third type of prospect plants. Genes of a bean protein have beenlic elements, which are toxic to plant follows the discovery by researchers at the transferred to the sunflower using this method.growth. Genetic engineers would dearly University of California, Berkeley, thatlike to fabricate plants resistant to such frost damage to strawberries is triggered bystresses, but success is unlikely in the near bacteria which act as nucleii for the forma¬future. Before being able to identify the tion of ice crystals on leaves. The cause is arelevant DNA sequences for transfer particular bacterial protein, the gene forbetween plants, they require a far better which the California biologists have learnedunderstanding of the many ways in which to delete. They believe they can prevent theplants respond to their environment. An extremely costly frost damage by sprayingadditional problem may be the involvement crops with this "ice minus" strain , which willof several different genes, as with nitrogen outgrow the natural flora. 15
  14. 14. The use of genetic engineering in food production offers many potential advan¬ tages. At the same time, questions have been raised about the possible risks in¬ volved in releasing genetically modified living organisms into the environment. One case which led to widespread debate and concern in the United States arose from the development and use of geneti¬ cally modified microbes known as ice- minus bacteria to protect strawberries from frost damage. In photo, the leaf at left has been treated with ice-minus bacteria. The leaf at right froze when dipped into supercooled water. I© Genetic engineering holds considerable in America, even natural weeds can cause about an organisms potential safety or per¬ promise too in the improvement of "biolog¬ considerable havoc. formance in nature. The scientific con¬ ical insecticides", microbes that attack pests The prospect of genetically engineered sensus is now for a gradual approach, a and have enormous ecological advantages crops themselves becoming weeds is priori evidence about a released organisms over their chemical counterparts. Bacillus remote, however, because crop varieties likely behaviour being used as the basis for thuringiensis, for example, has been used cannot compete well with other plants when successively larger trials during which expe¬ for many years to combat nuisance species, left unattended. The inherent difficulties of rience and confidence are gathered about but it and similar bacteria and viruses may mobilizing plant genes also make it unlikely how it actually does behave. well be made more powerful by recombi¬ that unwelcome varieties will be produced There is one other argument against the nant DNA. One possibility is illustrated by accidentally. And there is always the pos¬ much-publicized view in the USA that the pine moth, which damages lodgepole sibility of destroying by fire or other means organisms carrying recombinant DNA pine trees in northern Britain. In other parts an engineered plant, released initially in a should never be released for purposes such of the country, the moth is controlled natu¬ defined area, that did create problems. as pest control. One third of the worlds rally by a baculovirus that infects the cater¬ Nonetheless, field trials with novel plants, crops are now lost through infection and pillars. There are now plans to make the particularly crops able to cross-fertilize with pestilence. It would be foolhardy not to virus more efficient at killing caterpillars weeds, need to be very carefully monitored. make use of an ecologically acceptable tech¬ and to release it in the pine plantations. The Greater caution still is required with engi¬ nique capable of achieving even a modest first experiments are being carried out with neered microbes, which would be broadcast reduction in that toll. a virus that has been altered only by having in astronomical numbers and be impossible a "marker" introduced into a non-coding to trace in their entirety should anything go region of its DNA. This will allow awry. But it is reassuring that no health, researchers to follow the viruss distribution environmental or other dangers have been and survival after spraying. If all goes well, BERNARD DIXON, British science writer and caused by recombinant organisms since consultant, is European editor of The Scientist the virus may be given a genè allowing it to they were first fabricated over a decade ago. magazine and was formerly (1969-1979) editor synthesize an insect-killing toxin. The Moreover, biologists now agree that there is of the British scientific ¡ournalTUe New Scientist. potential for this technique in other coun¬ no significant difference between a microbe Notable among his published works are Magnifi¬ tries, against other destructive insects, is that has received a new piece of DNA cent Microbes (1976), Invisible Allies (1976) and clear. (with G. Holister) Ideas of Science, Man and through artificial manipulation and one that Medicine (1986). The safety of laboratory and industrial has acquired the same DNA fragment activities using engineered organisms is through natural mechanisms of gene trans¬ based on the idea of containment. Facilities fer. Most experts argue that recombinant are graded according to the degree of risk. DNA manoeuvres are intrinsically safer, New questions arise, however, when mi¬ because they can be vastly more precise and crobes and plants are to be introduced into selective. Certain laboratory manipulations the environment. There is concern, for are ruled out anyway by a priori predictions example, that weeds may be created acci¬ that they would generate hazardous recom¬ dentally and be inordinately difficult to binants. eradicate. If such a plant were drought- Many researchers believe that tests with resistant, herbicide-resistant, and frost-tol¬ recombinants should always be restricted toerant, it might spread quickly over large closed environments such as greenhouses.areas of agricultural land and be very diffi¬ But these "microcosms" can never simulatecult to eradicate. As illustrated by the the richness of the natural biosphere. SoKudzu plant in Asia and the water hyacinth they can never provide conclusive evidence 16
  15. 15. Tomatomation Japans high-tech food factories by Koichibara HiroshiTHE harnessing of high technology to Light, temperature and humidity are com¬ 85 (see the Unesco Courier, March 1985). vegetable farming may be about to puter controlled in this vegetable factory This was a major success for a hydroponic in a Tokyo suburb. High electricity con¬ culture system developed after many years trigger a new agricultural revolu¬ sumption is a drawback.tion in Japan, where some large manufac¬ of research by a Japanese agronomist,turers are already offering fully automatic Nozawa Shigeo. The growth of the plant"factories" in which vegetables are grown in was accelerated in a nutritive solution whicha computer-controlled artificial environ¬ replaced soil and in an artificially controlledment. In their use of automation and high development is hydroponics, the cultivation environment. As a result the plant pro¬technology these facilities resemble auto¬ of plants in nutritive solutions. Factory duced more than 13,000 tomatoes duringmobile or electronics plants, but instead of farms are air-conditioned, and high-pres¬ the six months of the Expo.automobiles or video tape recorders their sure sodium lamps provide twenty-four- Daiei, Japans biggest supermarketmass production lines produce fresh vegeta¬ hour-a-day illumination. The density of car¬ chain , has installed a factory farm next to itsbles, regardless of season or climate. bon dioxide, oxygen, temperature and store in the Tokyo suburb of Fanabashi. Strictly speaking, todays factory farming humidity are controlled by a computer to This experimental facility, constructed intechnology is based not on biotechnology maintain an optimum growing environ¬ co-operation with Hitachi Ltd. to grow let¬but on applying industrial production man¬ ment. tuce for sale in the adjoining supermarket,agement techniques to conventional agri¬ The hardware used in this process is not may be the worlds first commercial factorycultural engineering. The aim is to use new. It is readily available from manufac¬ farm using full automatic hydroponic cul¬artificially controlled environments to grow turers of electrical consumer goods, and this ture technology. The system produces someplants rapidly and efficiently rather than may be the reason why Japanese electrical 130 heads of lettuce and other green vegeta¬improve the adaptation of plants to natural conglomerates are active in this field. Com¬ bles per day (some 47,000 per year) on aconditions. Such ideas have already been panies in Denmark, the United States and floor space of no more than 66 squareapplied to poultry farming, egg production Austria are also experimenting with vegeta¬ metres. Grown from seed, the lettuce is bigsystems, and even the production of foie ble factories but for the moment the Jap¬ enough for harvesting in only five weeks,gras. Factory farms may thus make a big anese seem to be leading the field. 3.5 times faster than plants cultivated using In 1985, a "supertomato" plant was dis¬ conventional methods.impact on conventional agriculture sincethey provide planned cultivation regardless played in the Japanese government- In this futuristic factory, the sun isof weather, season, climate or soil. sponsored pavilion at an international replaced by artificial twenty-four-hour The essential element in this new exhibition held in Japan, Tsukuba Expo. lighting, soil with nutritive solution and 17

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