Historia biotecnologia


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Historia biotecnologia

  1. 1. Biotechnologies: past history, present state and future prospects Joseph H. Hulse Visiting Professor in Industrial Biotechnologies, UMIST, Manchester, UK and at CFTRI, Mysore, India and MS Swaminathon Research Foundation, India The paper presents a chronological review of biotechnologies, ancient and modern. It outlines the discovery of naturally occurring drugs by Babylonians, Egyptians, Chinese, Greeks and Romans, and the evolution of extraction, preservation and transformation technologies. It describes how pharmaceuticals progressed from empiricism, through chemical identification and synthesis to modern advances in genomics, proteomics, bio-informatics and syntheses by cultured cells from various genetically modified organisms. While biotechnologies for drugs first progressed through chemistry, until relatively recently food technologies evolved by mechanisation, the gra- dual replacement of human hands by machines. Present and predicted industrial demand for bioengineers exceeds supply. The cost and complexity of emerging biotechnologies call for significant revision of curricula and reorganisation of ace- demic departments related to life sciences and biotechnol- ogies. Urgently needed is active interdisciplinary cooperation in research and development, both in universities and industries, cooperation involving biochemists, bioengineers, mathematicians, computational scientists, systems analysts and specialists in bioinformatics. Bioscientists and bio- technologists must acquire more sensitive awareness of civil societies concerns and the ability to communicate with private citizens, politicians and the media. Recognising the inexorably rising demand for reliable health services, for safe and adequate food supplies, present and future opportu- nities for employment in industries devoted to food and drug technologies have never been greater. # 2003 Elsevier Ltd. All rights reserved. The British physicist Lord Kelvin gave as his opinion that if you can define precisely and measure exactly that of which you speak, your opinions can be counted as credible; if not, they must be deemed doubtful. Let me begin with a definition relevant to this discus- sion: ‘‘Biotechnologies are processes that seek to pre- serve or transform biological materials of animal, vegetable, microbial or viral origin into products of commercial, economic, social and/or hygienic utility and value’’. Bioengineers are men and women qualified to design, develop, operate, maintain and control bio- technological processes. One could cite instances in which (i) ‘Biotechnology’ is exclusively equated with genetic modifications and transgenesis, (ii) ‘‘Bio- technology’’ denotes a bioscientific activity that has not progressed beyond the research laboratory. In one American dictionary ‘‘biotechnology’’ is defined as synonymous with ‘ergonomics’: the study of human work in relation to a prevailing environment. The name ‘Biotechnology’ first appeared in Yorkshire early in the 20th century. A Bureau of Biotechnology began as a consultant laboratory in Leeds which from 1899 provided advisory services in chemistry and microbiology to fermentation industries in the north of England. The two Manchester universities (soon to be fused into one) have long and distinguished records in fer- mentation biochemistry. In 1912, Dr Chaim Weizmann isolated a strain of Clostridium acetobulylicum which converted carbohydrate into butanol, acetone and ethanol, a discovery extensively used for industrial production of acetone and butanol. In 1923, Dr Thomas Kennedy Walker welcomed the first students into his Department of Fermentation Industries, possibly the first of its kind, in what is now the University of Manchester Institute of Science and Technology. Later the departmental name was changed to Industrial Biochemistry, semantically similar to ‘biotechnology’. The undergraduate course was an amalgam of bioscience and bioengineering. From 1923 until he retired 35 years later, Professor Walker’s students advanced to senior positions in food, pharmaceutical and related bio-industries in very many countries. The interrelation of food and drugs This presentation assumes that most graduates in bioengineering will progress to senior positions in food, 0924-2244/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0924-2244(03)00157-2 Trends in Food Science & Technology 15 (2004) 3–18
  2. 2. pharmaceutical and related biotechnological industries. Though their historical patterns of growth and devel- opment have differed, food and drugs and the industries that produce them have long been closely associated. Standards of quality and safety for foods and drugs are customarily administered by the same regulatory agency, the US Food and Drug Administration being typical. As is discussed later, modern food and phar- maceutical processors employ similar technologies and methods of product and process control. Among the earliest historical records (ca 2900 BCE), the Chinese proclaimed a close association of foods with medicines, both being essential to good health, both derived from plant and animal sources. The Chinese believe many ailments can be cured by diet. They were the first to add burnt sponge, an aquatic source of iodine, for people suffering from goitre. The Emperor Fu-Hsi and his successors advocate that health depends on two principles: Yin and Yang. Yin weakness comes from malfunctions among internal organs and is indicated by a ‘hot’ condition, red tongue and weak pulse. Yang weakness results when internal organs fail to absorb essential nutrients, indicated by a ‘cold’ condition, Chinese medicinal foods are classified as ‘hot’ or ‘cold’, ‘strong’ or ‘weak’. Among an impressive list of Chinese medicinal foods, some are no doubt effective; others of dubious cred- ibility. Horn from deer antlers is claimed to relieve fati- gue, impotence and skeletal deformities. Ginseng root (Panax schinseng) is claimed, with little reliable phar- macological evidence, to alleviate diabetes, cardiovas- cular, digestive, liver and other diseases. Analyses of different samples from similar ginseng remedies show significant variance in composition. Oriental beliefs in therapeutic foods is attracting North Americans, one-third of whom are said to buy herbal remedies as alternatives to prescription drugs. Americans’ search for a nutritional Elixir vitae has been evident for over half a century. During the 1950s vita- min supplements were in fashion; during the 1960s pro- teins and amino acids were in favour; in the 1970s extensive publicity was given to essential fatty acids and cholesterol in relation to cardiovascular disfunctions; during the 1980s dietary fibre was of paramount inter- est. At present the fashion is with ‘functional foods’ (which beg the question: what are non-functional foods?) and ‘nutraceuticals’, foods believed to possess beneficial pharmacological properties. It is not surpriz- ing that the Chinese claim to be the originators of nutraceutical concepts. Food and drugs: science and technology A characteristic common to food, drugs and most other basic need industries is that technologies dis- covered by perceptive empiricism long preceded any scientific understanding of the biochemical properties of the raw materials and processed products. Foods found to be acceptable and satisfying, and medicinals that cured or alleviated particular maladies were discovered by chance, trial and error, and painful experience. The history of food processing, in large part, is a his- tory of bioengineering, the gradual replacement of human hands and energy first by animals, later by machines. Industrial processes of fractionation and transformation used today were developed hundreds of years ago. What began as labour-intensive artisanal crafts were progressively mechanized. In addition to providing an immense diversity of food products, food industries have progressively reduced the human effort and energy needed in factories, restaurants and homes. Food preservation The basic principles of food preservation: control of (1) active water content, (2) ambient atmosphere, (3) temperature, (4) pH; and (5) thermal inactivation of microbial and biochemical sources of spoilage, were discovered empirically hundreds of years ago. Medi- terranean, Asian and Amerindian people used sun dry- ing to preserve milk, meat, fish, fruits and vegetables, into their sun-dried pemmican northern Amerindians added dried berries that provided ascorbic acid. Sliced potatoes were freeze-dried by early Amerindians, ice gradually subliming in the dry air and low atmospheric pressure of the high Andes. Stone age Britons dried grains over open fires to prevent sprouting. Over 4000 years ago, the Chinese preserved fish by osmotic dehydration with salt. Republican Romans reduced water activity in meat and fruits by adding salt or honey. About 5000 years ago, Middle Eastern farmers stored grains in earthenware amphora each hermetically sealed by an impervious goat skin. All stages of insect metamorphosis were asphyxiated by respired CO2. Seneca described how Romans preserved prawns in snow from the Appenines. The frozen food industry developed after Clarence Birdseye, an American, observed how whale, seal and reindeer meat were naturally preserved during the cold Canadian winter. Modern canning, bottling and boil-in-the-bag were anticipated in Republican Rome where chopped spiced meats were sealed and boiled inside the cleaned womb of a sow or the body cavity of a squid. Fermentation and pickling of fruits and vegetables is an ancient practice among Asian and Mediterranean people. The Babylonians preserved their milk by lactic fermenta- tion. Ethanol was distilled in China over 3000 years ago. Homer described wine as ‘‘A gift from the gods’’. Grain milling—the first continuous process Fractionation of cereal grains by pulverization, siev- ing and winnowing, and extraction of olive oil by 4 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  3. 3. pressing, began in Egypt and nearby Mediterranean countries 7000 years ago. Commercial bakeries and breweries existed in Babylon and Egypt 5000 years before Eduard Buchner and Emil Fischer discovered the enzymic conversion of carbohydrates. The history of grain milling illustrates how labour- intensive artisanal processes were progressively mechanized. The primitive pestel and mortar gave way in Egypt to the saddle stone: where grain spread on a stationary smooth stone slab was pulverized by an upper stone pushed backwards and forwards by a kneeling slave. Later, the Greeks devised a shearing action by incising herring-bone grooves into the inter- faces of the upper and lower stones. In the rotary quern, evident in several ancient Medi- terranean countries, an upper stone was continuously rotated over a lower static stone. By cutting an eye-hole in the centre of the upper stone, grain was fed in a steady stream, the pulverized product being carried to the periphery by centrifugal force. Grain milling was the first known continuous industrial process. Rotary querns were at first driven by slaves walking on a treadmill, later by camels or donkeys. After the Romans invented the water wheel, through- out the Roman empire grain mills were built close by rivers or running streams. The Domesday Book, Wil- liam I’s inventory of the nation’s assets published in 1085, recorded over 5000 water mills in Britain. The first windmills appeared in Persia (now Iran) in the 10th century CE. In 1784, an early version of James Watt’s steam engine was installed in a London flour mill. Less than 100 years ago, in North America, more grain mills were powered by water wheels than by steam engines. The first mill powered by electric motors came on stream in 1887 in Wyoming. Though more precisely engineered, modern roller mills with their incised steel break rolls operate on the same principles as the early saddle stone and rotary quern. Hand winnowing has its modern equivalent in the middlings purifier, an enclosed vibrating gravity table with screens of diverse mesh size. Separated bran is removed by suction fans. A smart indigenous software programme enables modern wheat flour mills in India to be operated from a desk top computer. At the same time, poor rural Indian women grind local grains by pestel and mortar or saddle stone, and extract oil from groundnuts by rotary querns. Mechanization of traditional biotechnologies The patterns and pace of mechanization have pro- gressed differently among different industries. Though the transition from rural domestic spinning and weaving into large mechanized factories evolved over more than two centuries, in Britain the textile industry, stimulated by cheap coal carried on canal barges, and the steam engine, was mechanized faster than food processes. In the British baking industry, mechanical dough mixers were not much in evidence until after 1920. Mechanization moved more rapidly after World War II. During the 1930s, in a typical Manchester bakery, six men working an 8 h shift produced about 2400 loaves. In 1990, three men working an 8 h shift could produce over 65,000 loaves: 400 versus 22,000 loaves per man. The first significant change came in the 1960s when British scientists replaced traditional long fermentation processes by high energy mixing of bread doughs con- taining ascorbic acid. Continuous malting in breweries began with the Wanderhaufen moving malt couch. Continuous fer- mentations, in which the substrate passes over an immobilized microorganism or biocatalyst, are now common among modern bioindustries. Humphrey Davy’s discovery of finely divided plati- num as a catalyst led to the catalytic hydrogenation of vegetable oils to produce hard fats for shortening and margarine. About the same time, solvent extraction of vegetable oils competed with mechanical expression. In contrast to food processing, pharmaceutical industries advanced more from chemistry than engineering, start- ing in the 18th century in the German dyestuffs indus- tries after von Hofmann was appointed Professor of Chemistry at the University of Berlin. Pharmaceuticals in ancient times Survival and health, the fate of the human soul and body after death, and the supernatural influence of the sun, moon and stars intrigued many of our early ante- cedents. Primitive peoples searched for panaceas and palliatives to cure their diseases. Early Palestinians and Sumerians believed disease was a punishment for sin and could be mitigated by magical charms and drugs with supernatural powers. Shen-Nung (ca 2700 BCE) is acclaimed as the Chinese founder of acupuncture and drug therapy. He and his contemporaries described diabetes, smallpox, measles, cholera and various dysen- teries. Their 1800 medical prescriptions included ephe- drine, camphor, and cod liver oil. Arsenic and mercury compounds acted as bactericides. Respiratory diseases were treated by surrounding the patient in a pile of burning herbs. The Egyptian Ebers papyrus (ca 1550 BCE), dis- covered by 20th century archeologists, describes treat- ments for rheumatism, schistosomiasis, diabetes and intestinal parasites. It lists 875 drugs compounded from ca 500 substances: metallic salts, such vegetable extracts as gentian, senna, castor oil, vermifiuge and henbane. Sumerian cuneiform tablets from Hammurabi’s reign describe hepatic diseases, fevers, gonorrhoea, various strokes and scabies. Drugs included hellebore (believed to cure madness), mandrake root and opium. Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 5
  4. 4. During the 4th and 5th centuries, BCE, the Greek school of Hippocrates, published over 70 treatises on medical theories and practices, and prescribed more than 300 remedies, most from plants, to be administered orally or via other orifices. The Greeks were aware of potential dangers in drug therapy; the Greek word farmakon (Pharmakon) being translated as ‘drug’, ‘medicine’, ‘poison’ or ‘magic potion’. The Greeks believed that health (eucrasia) resulted from a harmonic blend, disease (dyscrasia) from imbalance among four humours: black bile, yellow bile, phlegm and blood. A tri-humorous concept of air, bile and phlegm existed among Ayurvedic Indians. Some 300 years after Hippocrates, Dioscorides, a Greek physician, regarded as the father of Materia Medica, formulated over 600 remedies from plant and animal tissues. Dioscorides’ medicines were prescribed for more than 1500 years. Galen of Pergamon, a physician of the 2nd century CE, added more veget- able remedies, known as Galenicals, to Dioscorides’ collection. Until the middle of the 19th century, medicine and pharmacy were more magical and mystical than scien- tific. Plantagenet physicians treated fevers by burying victims up to the neck in a dunghill; gout was treated with asses’ hooves; wealthy patients afflicted with ague, itch or erysipelas were dosed with finely ground amethysts, pearls and sapphires. It is difficult to discover what useful drugs the alche- mists discovered in their pursuit of the Elixir vitae, the elusive substance that would ensure eternal life. Alche- mists wrote their reports in cryptic codes and obscure symbols to confuse their competitors. What is compre- hensible is more redolent of the kitchen than the laboratory. Alchemical substances included sugar of lead, butter of antimony, oil of vitriol, cream of tartar and milk of lime. Paracelsus, a Swiss alchemist of the 15th century, is sometimes regarded as the father of chemistry. He dis- puted Galen’s theories and developed the notion of iatrochemistry: examination of substances to detect possible medicinal potency. He proposed various medical prescriptions. The first printed medical book: ‘Laxierkalender’—a treatise on laxatives—came from the Gutenberg presses in 1457. In 1564, the world’s first Pharmacopoeia Augustina was published in Augsburg. In 1616, the Royal College of Physicians published the Pharmaco- poeia Londonensis which listed drugs then permitted in Britain. Pharmaceutical industries In his book ‘Brave New World’, Aldous Huxley pro- posed that the history of economic and industrial development is of two periods: pre- and post-Henry Ford. I would argue pre- and post-Faraday as a more rational distinction. Though it needed Maxwell’s math- ematical genius 40 years later to transform Faraday’s electromagnetic induction principles into electric motors and power generators, the 1850s mark the point from which new technologies based on scientific principles appeared alongside empirically discovered technologies used to process foods, textiles, drugs and ceramics. After his mentor Humphrey Davy discovered the anaesthetic nitrous oxide, in 1818 Michael Faraday demonstrated that ether was a more effective anaes- thetic. But before von Liebig published his ‘Organic Chemistry in its Application to Physiology and Pathol- ogy’ in the mid-19th century, studies on the effectiveness of drugs can best be described as blindly empirical. For many centuries in Europe, pharmacy was the business of apothecaries who extracted and com- pounded medicines from natural vegetable and mineral sources. In Ancient Greece, physicians and apothecaries were discrete professions (an apoyek was a shop that sold drugs). In 1617, King James I created the Society of Apothecaries, giving them responsibility for production and sale of drugs and some poisons. Benja- min Franklyn defined the respective roles of American physicians and apothecaries, with laws that licensed apothecaries to sell drugs, poisons and narcotics. The first codified food and drug laws were enacted in 1860 in the United Kingdom. In the 19th century, British apothecaries worked with a Materia Medica cabinet containing 270 samples of roots, barks, leaves, seeds and chemicals. The British Pharmaceutical Society received a Royal Charter in 1843. A consolidated British Pharmacopoeia was pub- lished in 1864 and revised in 1898 and 1914. The 1864 edition described only four synthetic drugs; over 80 were listed in the 1914 edition, almost all imported from Germany. Before World War I, Britain had no synthetic pharmaceutical industry, only a few vaccines being processed. From empiricism to science From the mid-1800s analytical chemistry, microscopy and cytology made impressive progress. Chemotherapy was stimulated by identification of microbial pathogens and means by which they could be controlled. Wohler’s conversion of ammonium isocyanate into urea showed that naturally occurring organic substances can be syn- thesized from non-biological chemicals. Pharmacology progressed through research begun in Strasbourg on specific actions of drugs on particular body tissues. The world’s first Chair of Pharmacology was in Estonia. Discovery of hormones, extracted from endocrine and ductless glands and later synthesized, added an important dimension to therapeutic medicine and to development of pharmaceutical industries. Until the 20th century food processing progressed through engineering, pharmaceutical technologies 6 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  5. 5. through chemistry. Ancient remedies and plant extracts were the first raw materials of pharmaceutical indus- tries. Several drugs in early pharmacopoeias were later declared ineffective or dangerous. Active substances were dissolved in ethanol and/or water; compounded with diluents and pressed into pills coated with gelatin or sugar; or into tablets with poly- saccharide gums as binders, and lubricants to permit release from tableting machines. For treatment of skin wounds and infections, antiseptic drugs were dispensed as ointments in lanolin or water-in-oil emulsions. Drugs: natural and traditional Though today roughly 20% of all commercial phar- maceuticals are derived from natural and genetically modified microorganisms, there is lively commercial interest in natural and traditional sources. The Pfizer drug company was among the first to collect and screen botanical specimens from tropical forests. Merck in cooperation with the national Institute of Biodiversity is screening plants, insects and microorganisms from Costa Rica. Ethnobotanical expeditions in the tropical forests of the Amazon have delivered more than 10,000 species for examination. From Colombia over 1500 species, reported by local people to be biologically use- ful, are being studied. The ethical issue of biopiracy is being raised where foreign companies and their agents, engaged in botani- cal collecting, are taking away biological materials and indigenous experience in traditional medicine without reimbursement to local people. As observed by an Asian scientist: ‘‘We have the biodiversity, they [the affluent nations] steal it to support their biotechnologies’’. In response to public interest in ancient and traditional medicines, in 1992 the United States National Institutes of Health established an Office of Alternative Medi- cines. Data bases on ‘natural medicinals’ exist at the Royal Danish School of Pharmacy in Copenhagen, and at the University of Illinois, Chicago School of Medi- cine. The latter, known as NARPALERT, is adminis- tered by Professor Norman Farnsworth. Across the planet, there exists a vast unexplored source of plants and microorganisms. Of over 100,000 identified species, fewer than 200 microorganisms pro- duce substances used by food, pharmaceutical or other industries. The higher orders of terrestrial plants repre- sent more than 65% of the world’s biomass but fewer than 6% of identified species are commercially culti- vated. Of the 80,000 plants believed to be edible, fewer than 20 provide 90% of the world’s food calories. Synthetic drugs and chemotherapy During the late 19th century, encouraged by their success with synthetic dyes, the German companies Bayer, Hoechst and Merck began chemical synthesis of drugs, first making analogues and derivatives of active substances found in medicinal plants. The first propri- etary drug Aspirin—acetylsalicylic acid—was synthesized by reacting acetic anhydride with salicylic acid from willow bark (Salix spp). Later, codeine was produced by methylation of morphine. In the late 1900s, Paul Ehrlich observed how certain dyes injected into animals, stained specific tissues. Ehr- lich explored whether similar dyes would stain and inactivate microorganisms. He unsuccessfully tested 500 dyes on 2000 mice inoculated with pathogenic trypano- somes. He then synthesized more than 600 arsenic compounds with chemical structures similar to diazo dyes. His 606th compound inactivated the trypano- somes without adverse effect on the mice. The effective compound, named ‘salvarsan’, contained an –As¼As– group analagous to the –N¼N– group in diazo dyes and showed affinity with protein in the pathogen compar- able to the affinity of diazo compounds with protein fibres in wool. Salvarsan and its successor neosalvarsan, effective against Spirochaeta pallida the pathogen that causes syphilis, laid the basis for chemotherapy. In 1919, Heidelberger and Jakobs in Germany dis- covered that some azo derivatives of sulphanilamide destroyed bacteria. In 1935, a scientist at the Bayer company found the red azo dye prontosil to be effective against Streptococci that caused puerperal and scarlet fevers. In the 1930s, scientists at May and Baker in Britain synthesized over 600 sulphanilamide derivatives. The 693rd, which effectively treated bacterial pneumo- nia, was named M&B693. May and Baker synthesized over 3000 related compounds, several being effective bactericides. In 1936, the British Medical Research Council defined ‘Chemotherapy’ as medical treatment by synthetic che- mical compounds that react specifically with infective organisms. The process of synthesizing chemother- apeutic substances and determining potency in labora- tory animals is expensive and time consuming. Between 1936 and 1960, one of Britain’s largest pharmaceutical companies tested over 45,000 synthetics out of which only 16 became marketable drugs. During World War II, Britain lost access to Peruvian bark, the natural source of the anti-malarial quinine. Antimalarials were urgently needed to protect armed forces men and women posted to humid tropical countries. The only two synthetics available caused undesirable side effects. Between 1942 and 1946, the ICI Pharmaceutical com- pany tested ca 1700 synthetics before discovering pro- guanil hydrochloride, given the trade name Paludrine. ‘Malaria’ (literally ‘bad air’), is also known as ‘palud- ism’ or swamp fever (Latin ‘palus’=‘swamp’). Antibiotics While pursuing his microscopic studies, Pasteur sug- gested that microorganisms might be induced to attack one another. In 1928, Alexander Fleming, at London Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 7
  6. 6. University, observed that a mould spore from Peni- cillium notatum inhibited growth in a bacterial culture which it infected accidentally. The therapeutic potential of this discovery was overlooked until re-examined in 1939 by Howard Florey and Ernst Chain at Oxford. From their results, penicillin was isolated and chemi- cally characterized. Subsequent research in Britain and the USA identified other useful species and strains of Penicillium, synthesized penicillin derivatives, and developed systems of large scale culture, isolation and purification. Penicillin was but the first of an impressive series of antibiotics extracted from various species of Actinomycetes and other microorganisms. Long before Fleming’s discovery, primitive Micro- nesian people were known to scrape moulds from trees which they rubbed into wounds to prevent festering. Hormones More than 100 years ago, Claude Bernard, a French physiologist, reported that certain critical bodily func- tions are regulated by ‘‘centres of internal secretion’’. These were identified as endocrine and ductless glands that secrete hormones (Greek ‘hormon’=‘to urge on’). Adrenaline, first extracted from the suprarenal glands of animals, was chemically characterized in the 1920s and later industrially synthesized. In 1921, in Toronto, insulin was isolated from Lan- gerhens Islets extracted from porcine pancreas. During the 1980s, Canadian scientists synthesized an insulin precursor by a genetically modified bacterium. More recently, pancreatic cells that synthesize insulin were cultured, isolated, microencapsulated and transplanted into the bodies of diabetic patients to produce insulin in vivo. Thyroxine, generated by the thyroid, was synthe- sized in 1926, cortisone was isolated from the cortex of suprarenal glands in 1935 and commercially synthesized in 1956. In the intervening years, other hormones have been synthesized by GM microorganisms including avian and bovine growth hormones which stimulate body weight gain in farm animals and cultured fish, and milk production in bovines. Gonadotropins synthesized by GM bacteria induce gravid female fish to deposit their eggs when held cap- tive in aquaculture systems. The eggs are later fertilized by cryogenically preserved milt (male fish sperm). Synthetic oestrogen and progesteron steroids inhibit ovulation and/or fertilization in women. The 50 year history of oral contraceptives, and the related medical, social and religious issues are reviewed in two recent books: ‘Sexual chemistry: a history of the contraceptive pill’ by Lara Marks (Yale Press), and ‘This man’s pill: reflections on the 50th birthday of the pill’ by Carl Djerassi (Oxford University Press). Clinical trials on chemical contraceptives for males are in progress at the Human Reproductive Sciences Unit in Edinburgh, and by pharmaceutical companies in the Netherlands and Germany. Under investigation is a synthetic hor- mone, gestogen, which restricts reproductive processes in male gonads. Industrial biotechnologies—present value The earlier text outlined how food processing and pharmaceutical industries progressed over the past 6000 years. Food processing began with simple artisanal technologies, human hands being gradually replaced by machines. Not until the late 19th century did science become an influential force in food and drug industries. The pharmaceutical industry evolved from medicines compounded by apothecaries, most from local plant extracts, into chemical isolation, identification and synthesis of pharmacologically active substances and their derivatives. Given their importance to humans, commercial live- stock and domestic pets, it is not surprizing that food and drug industries constantly expand and diversify, to satisfy demands of expanding, affluent and aging popu- lations. The total world value of industrially processed foods is about $1750 billion USD. Sales value of com- mercial pharmaceuticals (not including veterinary med- icines) is close to $450 billion USD, 49% being sold in the USA, 24% in the European Union, 16% in Japan, with barely 11% for the rest of the world. Food pro- cessing industries, with sales over $500B per annum, comprise the largest industrial sector in the USA. Food industries in the EU employ more than 2.5 million peo- ple, they process two-thirds of all farm produce with sales close to $400 billion. Indian food processors employ more than 2 million people; at least 200 million Indians frequently buy processed foods. In 2002 the value of Indian processed foods was over 1000 times the value in 1962. It is impossible to estimate the total value of foods sold direct from farmers to local markets, or the propor- tion of food produced that is spoiled or wasted. Pharmaceutical industries—changing patterns Though several similarities between food and drug industries have been noted, there are divergent differ- ences. Pharmaceuticals are processed by relatively few large corporations, while food industries include such giants as Nestle and Unilever together with thousands of medium and small scale companies. Pharmaceutical companies invest between 9 and 18% of their revenues in research and development. The average R&D investment for some 3500 Canadian registered food processors is less than 0.15% of sales revenue. Most pharmaceutical companies began as divisions of, or spin-offs from chemical industries and expanded through acquisitions and mergers. In 1953, Watson and Crick described the helical structure of DNA. In 1973, the first gene was cloned, in 1974 cloned genes were expressed in a foreign bacterial species. In 1976, Genentech became the first company in 8 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  7. 7. the USA created for research to explore and exploit DNA. Between 1981 and 1999, specialist bioscience companies in the USA grew from 80 to over 1270. Ernst and Young report 1180 such enterprises among EU member countries. Many evolved from university bioscience departments. Some were highly successful, others with insufficient venture capital, and inexper- ienced management, did not survive. Academic scientists with ambition to own a specialist bioscience company should have access to deep cash pockets. Risks are high and profitable innovations do not come quickly. The biomedical industry now consists of two inter- related entities: (1) large pharmaceutical corporations (2) specialist bioresearch enterprises, described as ‘Second generation biotechnology companies’. In 2001, total revenue of the six largest bioscience companies was ca $8 billion; research and development investment between 20 and 37% of revenue. They devise and develop new processes and products to pilot plant and preclinical stages. Pharmaceutical companies expand the processes and subject the products to in vitro and in vivo clinical trials to determine potency, reliability and safety. For a new drug to progress from the laboratory to final approval may cost between $300 million and $800 million and take between 10 and 15 years. Biotechnologies: future prospects Over the past 20 years, biotechnologies have evolved from intellectually intriguing biosciences into diversifying industries that produce useful biologicals from biocata- lytic reactions, genetically modified bacteria, funghi, viruses, plant, mammalian and insect cells. Some tech- niques modify genetic composition and expression; oth- ers accelerate and adjust metabolic processes. Of particular interest to bioengineers are reliable means to expand from laboratory to factory scale, and technolo- gies for the isolation, purification and sterilization of end products. Equally critical are reliable systems of product quality and process control. Earlier processes of extracting, screening and chemi- cally modifying natural biochemical substances are giv- ing way to identification of how specific diseases are caused, how particular drugs act to prevent or cure them. More effective diagnostics, prophylactics and therapeutics are being designed and synthesized by molecular modelling and combinatorial biochemistry. In the past, an organic chemist might synthesize 50 new compounds in a year, computer-assisted modern bio- chemistry can generate several thousand. Computers devise molecules to be systematically compared with computer-stored molecular structures. One company screens a million compounds against a target protein every 6 months. Rapid biological screening makes use of membranes from human or animal organ cells grown in tissue cul- ture. Immunogenicity of specific antibodies can be improved by computer modelling. Diagnostic processes are enhanced and speeded up by molecular modelling, by DNA microchips, and by recent advances in genomics, a name coined in 1980. Drugs synthesized by GM organisms include vac- cines, immune regulators, substances to control cardio- vascular disorders and various hormones. Modern vaccines include (1) toxoids-inactivated toxins extracted from cultured pathogens (for tetanus and diphtheria); (2) attenuated pathogens (for pertussis—whooping cough); (3) isolated biochemically modified antigens of various novel applications. Vaccines from GM viruses include whole virions (poliomyelitis); split vaccines (influenza); isolated antigens (hepatitis B). Recent additions to the biosciences lexicon include ‘Genomics’—study of genomes and DNA nucleotide sequences; ‘Proteomics’—related to specific proteins pro- duced by genomes; ‘Metabolomics’—influence of gene expression on metabolites; ‘Transcriptomics’—profiling of gene expressions using DNA/RNA micro assays. Bioengineering processes The immense diversity of active products from bio- technologies includes whole viable or attenuated cells, metabolites within cells or diffused into the culture medium. Typical industrial processes progress through several stages: i. Identification and isolation of cells to be cul- tured. ii. Determination of optimum culture and harvesting systems. iii. Scale-up to large batch or continuous bio- reactors. iv. Down-stream processes for fractionation, extraction, purification and sterilization. v. Methods for process control and product quality. vi. Protocols to ensure safety and containment throughout development and production. The over-riding objective is to maximise economic yield of stable effective products. A bioengineer with many years of experience recently said: ‘‘Even where genetic modifications, laboratory and pilot plant trials are entirely successful, scale-up to an economically effi- cient industrial process is inevitably frustrating, more costly and time-consuming than was forecast.’’ In addition to synthesis by microorganisms, develop- ments are progressing with cells from higher plants, animals, insects and GM viruses. Bacteria and viruses are cultured for metabolite synthesis, and for use as vectors to transfer genes between organisms. Cells may be cultured in batch bioreactors or in continuous sys- tems where the nutrient medium percolates through or over and is transformed by the immobilized cells. Simi- Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 9
  8. 8. larly, metabolites may be synthesized by isolated, immobilized enzymes. Plant cell culture begins by propagation of a callus, a mass of undifferentiated cells. To derive a new plant with shoot and root, cells from the callus must be cul- tured in different media. Desirable metabolites can be extracted from a callus without progression to a shoot and root. Plant cell culture seems better suited to synthesis of metabolites useful in foods, biopesticides and cosmetics than for biomedicals. Mammalian and insect cell cultures offer more inter- esting opportunities for biomedical applications. Sour- ces of mammalian cells include kidneys from aborted embryos and ovarian cells from Chinese hamsters which replicate relatively rapidly. Insect cell cultures, in com- bination with GM virus vectors, produce recombinant proteins and viral insecticides. The baculo virus, which infects insect cells, genetically modified yields specific proteins in high-density insect cell culture. Mammalian cells generate metabolites of greater pur- ity, potency and complexity than most microbial cul- tures but, being highly sensitive, require careful culture in relatively small bioreactors. Means to expand mam- malian cell culture in batch or continuous systems pre- sents an interesting challenge to bioengineers. Monoclonal antibodies, plasminogen activators, hor- mones to stimulate blood cell growth and Factor VIII to control blood clotting are among products from mammalian cell culture. In association with specific viruses mammalian cells will produce viral vaccines and recombinant proteins used in gene therapy. In 1997, Human embryonic stem cells (HESC) were isolated from discarded human embryos. It is postulated that pluripotent stem cells may be cultured into different cells with the capacity to replace or repair cellular tis- sues in various human organs. Whether embryo stem cells will realise their hypothetical potential seems to depend as much on legislation influenced by religious belief as on bioscience. Downstream processing ‘Downstream’ relates to all that follows bioreactor synthesis: the isolation, purification and sterilization of end products. Downstream processes are estimated to absorb ca 80% of production costs, indicating an urgent need for more economical downstream technologies and bioengineers competent to design and operate them. Isolation Synthesized substances are isolated from various bioreactor fractions: insulin from harvested cells, some vaccines from supernatant fluids. intra-cellular metabo- lites are released by mechanical, chemical or enzymatic rupture of cell walls; antibiotics by liquid:liquid extrac- tion; tolerant volatile substances by fractional distilla- tion; heat-sensitive enzymes by aqueous phase liquid fractionation. Supercritical gas/liquid extractions (SGE) are useful for substances sensitive to organic solvents or susceptible to oxidation. At pressures between 10,000 and 40,000 kPa, carbon dioxide is a benign solvent for essential oils, oleoresins, natural terpenoids, caffeine, and other sensitive biochemicals. Unlike many organic solvents, SGE leaves no toxic residues. Membrane processing, reverse osmosis, ultrafiltra- tion, microfiltration, nanofiltration and electrodialysis are among other industrial fractionation technologies. Chromatographic systems include gel filtration, ion- exchange and affinity separations that use binding interactions between proteins and packing materials, with various ligands coupled into hydrophilic support matrices. Preservation and sterilization Foods are for healthy nourishment; drugs to diag- nose, prevent or cure disease. It is critical that all foods and drugs be free from organisms that may cause insult or injury to those who consume and use them. Gen- erally speaking, biological materials such as foods and pharmaceuticals can be preserved by any process that (1) inhibits, destroys or removes and prevents re-entry of pathogenic and microorganisms that cause spoilage; (2) restricts adverse biochemical and biophysical change. Degradation of food and other biological materials can be restricted by packaging under inert atmosphere, by reducing water activity and thermal sterilization. Freeze-drying effectively lowers water activity in sensi- tive biologicals. Rapid freezing in liquid nitrogen prior to freeze-drying (lyophilisation) restricts cell disruption by slow-growing ice crystals. Thermal processes and alternatives Thermal processing in hermetic containers (cans, bot- tles, laminated plastics) takes a long time for heat to be conducted throughout the material. Excessive heating of foods and other biologicals can cause adverse change in critical functional properties, nutritional quality, fla- vour, physical structure and texture. The higher the temperature, the longer the time, the greater the degree of biochemical and biophysical change. Existing processes that reduce heat damage include spray-drying, tubular and scraped surface heat exchan- gers, and steam injection followed by aseptic packaging Several alternative means of preservation are in various stages of investigation and development. Irradiation Ionising radiations can inactivate microorganisms and kill insects. Radiation sources for food and phar- maceuticals include gamma rays from radioisotopes Co60 or Ces137, X-rays or electrons generated by machines. Absorbed radiation is measured in Grays or 10 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  9. 9. kiloGrays (kGy), 1 Gray being equivalent to 1 Joule per kg. In the USA, irradiation is permitted for microbial control in dehydrated enzymes (10 kGy), spices (30 kGyJ), poultry (3 kGy), various pharmaceuticals and other biological materials. Data in parentheses are maximum permitted doses. The higher the dose, the greater the inactivation of microorganisms. High doses can induce molecular disruption and generate highly reactive free radicals which in turn cause unpredictable biochemical modifications. In general, higher doses are permitted in biologicals consumed in small quantities (e.g. spices) or in prescribed pharmaceuticals. A WHO 1997 report states that at legally permitted doses, irra- diation of foods will not cause toxicological difficulty or significant nutrient loss. Apart from consumers’ suspicions, still evident, the main constraints to food irradiation are economic. Capital costs are high, emissions from radioactive iso- topes cannot be switched off, so to derive maximum benefit there must be a constant supply, 24 h every day, 365 days every year, of high value material to be pro- cessed. Irradiation processes call for skilled bioengineers and physicists to ensure safety of all workers who must come close to the equipment. In most cases, irradiation is uneconomic for grain disinfestation even at the rela- tive low doses required. Ohmic heating When an electric current flows through a substance of suitable conductivity, heat is uniformly generated. Ohmic heating is effective for fluids and particles suspended in fluid media. The fluid is pumped through a column between two electrodes between which the current pas- ses. The sterilised product is rapidly cooled and passes aseptically into sterile containers. Heating is uniform and of short duration. Commercial models range from a 10 kW pilot scale that processes 100 kg/h, to 300 kW machines to process 3 t/h. Capital costs range between 375,000 and two million pounds sterling. Operating costs depend on the power consumed and properties of the products processed. Microwave (MW) and radio frequency (RF) heating MW and RF depend on electromagnetic energy gen- erated from a magnetron to produce an electric field that alternates at radio or microwave frequencies. Heat is generated in biological materials by rapid reversal of molecular polarization. MW and RF provide uniform, short-time heating with high internal temperatures. Most widely known are domestic MW ovens, indust- rially MW and RF processes are used in dehydration, microbial inactivation and cooking. International electromagnetic compatibility regula- tions limit industrial processes to specific frequency bands that do not interfere with communication sys- tems. Quartz crystals facilitate controlled outputs ran- ging from 500 W to 50 kW with 80–90% energy efficiency. Computer modelling programmes determine optimum conditions for different purposes. Main con- straints include relatively high capital costs and need for highly skilled engineers for operational control. Ultra-high hydrostatic pressure (UHP) Lethal effects on microorganisms of isostatic pres- sures between 500 and 10 k bar (50 kPa–1 MPa) were discovered over a century ago. UHP food processing has been applied mainly to fruit juices and jams. Industrial equipment maintains pressures from 400 to 800 MPa. Biomaterials in flexible or semi-rigid packages, evac- uated before sealing, are immersed in a fluid in a high pressure vessel. The UHP is transmitted through the fluid to the biomaterial. In acidic products vegetative cells are inactivated at 400 MPa, bacterial spores after 30 min at 600 MPa. UHP minimizes loss of nutritional and functional properties. Constraints include high capital cost, precise engineering and skilled operational control. Pulsed energy Three forms of pulsed energy for microbial inactiva- tion are under study: (1) Pulsed electric fields (PEF); (2) Pulsed light (PL); (3) Pulsed magnetic fields (PMF). With PEF, induced electric potential causes lethal irre- versible polarization of cell membranes. Critical poten- tial varies with species, cell morphology and ambient conditions. Vegetative cells are inactivated at field strengths between 15 and 30 kV/cm, alternating polarity pulses being more effective than constant polarity. Pulsed energy is not yet effective against spores or degradative enzymes. Pulsed light activates an inert gas lamp to generate broad band light flashes, 20 000 times the intensity of sunlight at the earth’s surface. PL is effective against surface vegetative organisms. Pulsed energy systems bear high capital costs and need precise operational control. Ultrasonics (US) Ultrasonics use sound waves at frequencies higher than detected by human ears (20 kHz). Microbes in liquid suspension are inactivated by alternating pres- sures and cavitation. With mild heat, US inactivates vegetative cells and can remove dirt inaccessible to con- ventional cleaning. US is used industrially to accelerate or control crystallization, filtration, hydrogenation of lipids and aging of alcoholic beverages. Process and product quality control (QC) Simply defined, QC objectives are to ensure (1) the properties of raw materials and final products comply with defined specifications; (2) consistency of essential Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 11
  10. 10. properties among all production runs. Specifications are laid down by (1) international protocols, (2) govern- ment regulatory agencies, (3) customers, secondary processors and retailers; (4) processing company man- agers. Specifications, analyses and assessments of foods and drugs are designed to ensure safety to consumers and effectiveness within the conditions prescribed for use. More than 8000 processed foods and 7000 approved drugs are commercially produced in North America and Europe, together with unknown quantities of traditional foods and drugs on other continents. A comprehensive account of all recommended and tentative QC proce- dures would fill many CD Roms. This paper offers only an overview of present trends and practices. Bioengi- neers must ensure that materials of construction are compatible with biological materials to be processed. Processing equipment must be easy to clean and, where necessary, to sterilize. On-line systems Analyses of random samples from finished products in a quality control laboratory is gradually being superseded by control systems that use on-line sensors, probes and monitors that continually assess critical properties. When a defective property is identified, a feed-back signal corrects the faulty processing para- meter, all on-line determinations being recorded in a computer. More than 100 devices determine flow rates, apparent viscosities and various rheological properties. Others record temperature, pressure and RH gradients. Various critical properties are assessed by change in electrical conductivity or dielectric constant. Chemical sensors respond to changes in pH, specific ions, organic radicals and impurities. Biosensors employ immobilized bac- teria, enzymes, antigen-antibody reactions and DNA probes. By multivariant analysis of responses to mixed aromatics, an electronic nose can detect desirable or obnoxious odours. Spectroscopic on-line methods are too many and diverse to be catalogued. Ultrasonics detect particle size distribution, emulsion breakdown and various adulter- ants. Near infra-red can be calibrated to determine moisture, protein, lipid and various other component concentrations. Magnetic resonance imaging is an advanced spectroscopic method based on different magnetic properties of atomic nuclei when placed in a magnetic field. The field induces different energy levels between protons aligned with and protons aligned against the field. MRI, most widely used to diagnose defects in the human body, now is applied to detect infections in aseptically packaged foods and drugs. Being non-destructive, it offers 100% inspection of critical biological materials. Immunological methods attach enzyme labels to antibodies to react to specific pathogens, hence the name ‘Enzyme linked immunosorbent assays’ (ELISA). Automated ELISA systems are based on a dipstick technology originally developed for testing pregnancy in women. An ideal sensor must be accurate, reliably responsive, robust and tolerant to processing conditions, easy to install and maintain, inexpensive in relation to product market value. Magnetic Resonance Imaging (MRI) and other expensive systems are economic for pharmaceu- tical but generally too expensive for most industrial food processes. On-line control systems are as much the responsibility of production bioengineers as of quality control bio- chemists and microbiologists. Many on-line sensors and probes determine a reaction or response indirectly rela- ted to the property critical to product safety and effec- tiveness. Bioengineers must therefore comprehend the relation between the response recorded and the critical product property to be determined. Sensors and their responses should be systematically checked and correlated with direct methods of determination. Quality control (QC) and genetically modified (GM) organisms The use of living organisms to synthesize pharmaceu- ticals, the complexity of the process technologies, call for changing patterns of process and product control. In addition to ensuring product safety and effectiveness, control systems must characterize and monitor organisms used, cell culture conditions, reaction, recovery and pur- ification processes. QC of biologicals produced by viruses, microbial, plant, insect and mammalian cells is more com- plicated than of pharmaceutical substances isolated from medicinal plants or synthesized by chemical reactions. Accurate analysis of novel proteins synthesized by rDNA in GM organisms is an important priority. Pro- gress is evident in automation of electrophoresis, amino acid analysis and gene sequencing. HPLC coupled with mass spectrometry and immunochemistry is extending the frontiers of protein analysis. Robotics, though rela- tively slow, are useful for tedious activities such as iso- tope labelling. Of urgent need are reliable methods to determine picogram levels of possible oncogenic DNA in mammalian cell cultures. The future of bioengineering From the data provided by the Ernst and Young regional biotechnology studies, from other publications and discussions with biotech industry executives, it is clearly evident that the demand for bioengineers and biotechnologists exceeds present and predicted supply. One study forecasts that over the next decade industrial opportunities for bioengineers will rise by 80%, for research and development bioscientists by ca 60%. Since the mid-1970s, modern biotechnology industries have generated more than 100 new drugs and vaccines. 12 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  11. 11. In the year 2000, world-wide investment in biotechnol- ogies amounted to $37 billion USD which, according to a recent Canadian study, is expected to increase by 30%/year over the foreseeable future. According to a McKinsey Company report, biotechnology research and industrial development appear attractive to venture capital of which, in Canada, 90% is invested in the health care sector. Whether or not these predictions of future growth will be precisely accurate, expansion and diversification of bioscience and bioindustries seems inevitable given that most governments among European Union and North American nations declare health care, food safety and environmental protection related to human and animal health as high priorities. At the time when pharmaceuticals were mainly derived from medicinal plants and chemical synthetics, factory engineers were mostly chemical engineers. It is now evident that classical chemical engineering is inadequate for modern and advancing techniques of biosynthesis, extraction, isolation and purification of biologicals produced by various cell cultures and genetically modified organisms. The academic qualifications and experience needed in industrial bioengineers are rapidly changing. To provide the knowledge and skills industries need, universities must evolve from traditional unidisciplinary, narrowly specialised departments into integrated interdisciplinary units. The Manchester Interdisciplinary Biocentre [MIB] illustrates how academic bioscientific research and teaching must be organised in the future. In a newly designed facility, the MIB will be staffed by biophysi- cists, biochemists, mathematicians, computation scien- tists bioengineers and systems analysts. Bioengineers, together with all other involved disciplines, must work cooperatively from the early synthesis through to fac- tory-scale processes, the whole being integrated into an orderly organisation by mathematically-trained systems analysts. An academic evolution to active, organized interdisciplinary teaching, research and development is essential for all biosciences and biotechnologies: phar- maceuticals, food and all else on which healthy lives depend. Recognizing the rate at which bioscience is expanding and diversifying, university departments could profit- ably emulate their schools of management colleagues by offering short, intensive courses to enable industrial biotechnologists and bloengineers continually to upgrade their knowledge and skills. To satisfy the evol- ving needs of modern bioindustries, universities must critically assess and, in some instances, restructure their departmental organizations, curricula and research programmes. An obiter dictum from Rene Descartes’ ‘Discourse on Method’ seems apposite and appropriate. ‘‘All that is at present known is almost nothing in comparison with what remains to be discovered. . . . We could free our- selves from an infinity of maladies of body and mind if we had knowledge of their causes and the remedies provided by nature’’. Chronologies of biotechnologies for food and drugs BCE (BC) 4th/3rd Millennium Egyptians developed grain milling, baking, brewing. 3rd Millennium Chinese Emperor Fu-Hsi proposed health food principles of Yin, Yang. Chinese Shen-Yung Originator of acupuncture and natural drug therapy. Prescribed 1800 biological and chemical reme- dies. Egyptians, Sumerians preservation of milk, vegetables by acid fermentations. 2nd Millennium Egyptians prescribed plant remedies for rheu- matism, diabetes, schistosomiasis. Sumerians treated hepatic diseases, gonorrhoea, strokes and scabies. Chinese distilled ethanol. Burnt sponge (iodine) to alleviate goitre. 1st Millennium Natural, open-air freeze-drying of potatoes by Andean Amerindians. 5th/4th Century Hippocrates School of Medicine Hippocratic Oath; 70 medical treatises; 300 remedies. 4th Century Aristotle classified known plants and animals; Theophrastus wrote ‘History of plants’. Greek word ‘Pharmacon’ means both medicine and poison. 2nd Century Dioscorides: Father of Materia medica; pre- scribed >600 drugs and remedies. Romans invented the water wheel. Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 13
  12. 12. CE (AD) 2nd Century Galen of Pergamon: Many drugs known as Galenicals. Alchemy began in Alexandria; continued until 16th Century. Alchemists influenced by chromatic and mor- phological associations (e.g. red wine and red meat generated good blood; white wine and meat conducive to anaemia). Yellow saffron prescribed for jaundice: lung-shaped leaves of lungwort for respiratory diseases. 10th/11th Century Persians invented the windmill. Avicenna translated Aristotle, Dioscorides, Galen other early Greeks into Arabic. Arabians Materia medica: medicinal plants, extracts from wood and tree bark. 15th/l6th Century First medical text book on Laxatives printed on the Gutenberg Press. Paracelsus practised alchemy and medicine, dis- covered laudanum and opium. Drugs classified by function: hypnotics (opium, poppy juice, atropine from nightshade); pain relievers, anti-pyretics (willow bark, laudanum, strychnine); laxatives (castor oil, senna); emetics (tartar emetic); diuretics (Digitalis later for car- diovascular disorders). Derivatives of copper, mercury, antimony and sulphur—wonder drugs of the Renaissance. Mercury for syphilis later discovered to cause neurological toxicity. World’s first pharmacopoeia printed in Augs- burg. Antimony (tartar emetic) ‘a panacea’; later shown to cause cardiovascular collapse. 17th Century King James I created British Society of Apo- thecaries. Digitalis discovered in UK—foxglove a rural folk remedy for dropsy. Thomas Sydenham, Birmingham physician, dif- ferentiated between scarlet fever and measles. William Harvey described heart as stimulus for blood circulation, measured blood flow. Peruvian bark, brought to Europe by Spanish Jesuits, therapeutic for malaria (Lit. ‘bad air’) later discovered to contain quinine. Robert Hooke, (cf Hooke’s Law: relation between stress and strain in elastic materials) described cellular structure of cork and various plant tissues. Anton von Leeuwenhoek (Netherlands) invented a microscope (magnification 30Â) described blood corpuscles, cells in fish tissues and ‘ani- malcules’ (protozoa) present in organic matter in ponds. 1664 Thomas Willis (Oxford) described human brain and cranial nerves. 1670 Kaspar Bauhin (Swiss) classified higher plants into genera and species. 1679 Hamm (Netherlands) discovered sperma- tozoa. 1690s First herbarium of North American plants by immigrant physician to Canada. First studies of medicinal plants used by native aboriginals. 18th Century Linnaeus (Swede) formulated taxonomic system of classification for plants and animals later refined by Antoine de Jussieu (for plants) and Georges Cuvier (for animals). Edward Jenner observed British milk maids immune to cowpox. Jenner developed refined method of vaccination with controlled doses of cowpox serum. Jenner’s process safer than older Asian processes [‘Vacca’ (Latin)=Cow]. 1763 Extract of English willow bark relieved arthritis and rheumatic pain (salicylic acid iso- lated a century later). French pharmacien Pelletier isolated an emetic from ipecacuanha, strychnine from an Indian tree (genus Strychnos), morphine from opium poppy seed, brucine from angostura, quinine from Peruvian bark, caffeine from coffee berries, veratrine (jervin) from hellebore. Spallanzani (Italian) sterilized foods and organic materials by heating in hermetic containers. Spallanzani demonstrated fertilization of eggs by spermatozoa. 1798 Thomas Malthus ‘Essay on Population’. Human population will exceed food supply. Pharmacy as discrete profession combining apo- thecaries’ arts, botany, chemistry. First chair of Pharmacology at Dorpat in Estonia to study effects of therapeutics, toxicology, phy- siology and botany. 19th Century Humphrey Davy discovered nitrous oxide as anaesthetic. Michael Faraday discovered ether as anaesthetic. 14 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  13. 13. Rudolph Virchow diagnosed and described leucaemia, thromboses, embolisms. Virchow’s hypothesis: cells ultimate units of all organic life and pathological disturbance. Virchow’s cellular theory of pathology coincident with atomic theory of physics. Virchow’s studies plus advances in analytical chemistry formed basis of pharmacology: chemical composition related to therapeutic function. Alkaloids first therapeutics isolated: morphine (1806), strychnine (1818), quinine (1820) 1816 G. Cuvier (French) categorised animals in four classes: Vertebrata, Mollusca, Articulata, Radiata. 1832 J. von Liebig (German) demonstrated that chloral hydrate induces sleep. 1820 Bracconot (French) hydrolized gelatin to produce glycine, meat and wool—leucine. 1838 Berzelius (Swedish) coined the name ‘‘Pro- tein’’ (Greek Åroteos—Proteos: ‘that which comes first’) for nitrogenous organic compounds. 1846 von Liebig isolated tyrosine. 1860–1900 Most other essential amino acids isolated. Last was threonine in 1930. 1840–50s J. von Liebig recognized proteins, lipids, carbohydrates and various minerals as essential to human and animal nutrition. 1854 Lawes and Gilbert (UK) demonstrated difference in nutritive value among plant proteins fed to pigs. 1825 F. B. Raspall, using iodine as a dye, revealed the distribution of starch in plant cells. Regarded as the founding father of histo- chemistry. 1828 Friedrich Wohler (German) synthesized urea from inorganic ammonium isocyanate. 1827 K. E. von Baer (Estonian) described the mammalian egg. 1830 Robert Brown (Scotland) described nuclei in plant cells. 1838 M. J. Schleiden and Theodur Schwann (Germany) cooperatively recognised the similar- ity on nuclei in plant and animal cells. From early 1830s active interest in cytology. 1840–80 Progressive discovery of chromosomes— naturally colourless, made visible by selective affinity with chemical dyes. 1840s–60s Several reports that organisms develop by repeated cell division organic cells consist of nuclei embedded in protoplasm, (Greek ‘first to be moulded’). 1840s William Perkin (UK) trying to synthesise quinine from analine sulphate accidentally pro- duced first synthetic dye: mauveine, laid basis for the European dyestuffs industries. 1847 J. Y. Simpson (Edinburgh) nitrous oxide, ether and chlorophorm as anaesthetics. 1855 Nathaniel Pringsheim (German) reported fusion of male spermatozoa with female ovum and how resultant cell differentiated into new orgnanisms. 1870s E. Strasburger and Oskar Herrwig (Germany) described (1) division of nuclei, (2) fusion of two nuclei one from each parent. 1858 A. R. Wallace (UK) Theory of evolution— transmitted to Charles Darwin. 1859 Charles Darwin ‘On the Origin of Species by means of Natural Selection’. 1850s German chemical and pharmaceutical industries developed. Chemical synthesis of drugs. Among first, amyl nitrate to treat angina pectoris. Alkaloids atropine, cocaine and nicotine synthe- sized. 1870 Veronal (phenobarbitol) synthesized by Emil Fischer. 1835 Agostino Bassi (Italian) reported disease in silk worms caused by microfungus. 1860s Casimir Davaine (French) identified bac- teria in blood of animals infected with Anthrax bacteria. 1860s Louis Pasteur (French) proved micro- organisms are the cause not the result of fer- mentation in decaying matter. 1860s–80s Pasteur revealed the link between bacteria and disease by studying infected silk- worms, other sources of pathogens. He showed bacteria as the cause of acidity in beer. Whitbreads UK brewery—first to use microscope for quality control. 1860s Robert Koch (German) devised selective staining to assist microscopic identification of microorganisms. 1882 Koch identified Mycobacierium tuberculo- sum as the infective cause of pulmonary tuber- culosis. Koch’s diagnostic procedure: (1) isolate and culture the organism; (2) infect laboratory mice with the cultured organism; (3) recover the organism from mouse tissue. 1867 Joseph Lister (UK surgeon) used phenol to disinfect wounds. 1870 C. J. Eberth (German) laid the basis for virology by filtering out Anthrax bacteria from blood from which Pasteur diagnosed diseases caused by microscopically invisible organisms that passed through microbial filters. Pasteur began diagnosis of viral diseases. 1866 Gregor Mendel identified inheritable characters in noticeably different pea varieties. Mendel’s results ignored until rediscovered by American scientist in 1900. Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 15
  14. 14. 1880 First pharmaceutical industries in UK. Most R and D in government laboratories cf Germany: most by private industry. Burroughs Welcome most research active in UK. Pharma- ceutical companies treated with suspicion in USA, (American Society for Experimental Pharmacology excluded industrial pharmacolo- gists until 1941). 1883 Johann Kjeldahl (Netherlands) Analytical method to determine nitrogen in proteins. 1890s Isolation of substances active in endo- crines: suprarenin and thyroidin. 1890s Paul Ehrlich demonstrated affinity of various cells for particular dyes permitting microscopic identification by staining of micro- organisms and cells from various organs. Ehrlich demonstrated affinities between parti- cular cells and certain drugs. He synthesized salvarsan (arsphenamine) and neosalvarsan (neoarsphenamine) effective against Spirochaeta pallida the infective pathogen for syphilis. Littlefurtheradvanceinchemotherapyuntilsulphur drugs (1930s) antibiotics (1940s) Scientists at Edinburgh University determined composition of various alkaloids, and pharma- cology of strychnine, codeine, morphine, atro- pine and derivatives. Chemotherapy began with discovery and ther- apeutic control of pathogenic organisms. Vaccines for cowpox, cholera, typhus and typhoid developed. In vivo synthesis and extraction of hormones from animal tissues. Extracts of thyroid gland relieved myxodemia; adrenal extracts raised blood pressure. Living tissue used to monitor therapeutic activ- ity, and for quality control. 1895 X-rays discovered by Roentgen applied in diagnostics. 20th Century Recognition that Mendel’s theory of inheritance applies to all plants and animals. Chromosomes composed of genes that control sex and biological characters of organisms T. H. Morgan (USA) elucidated nature and function of genes by work on Drosophila spp. From 1900 More scientific progress in pharma- cology, biosciences than in past 5000 years. Purified isolates, derivatives and synthetics replaced simple remedies. Animal experiments complemented in vitro and empirical studies from human patients. Early 1900s Emil Fischer (German) synthesised long-chain peptides form 18 amino acids. 1914 Thyroxine isolated. 1921 In Toronto: Insulin isolated from Lan- gherens islets in pig pancreas. UK Large scale vaccination against diphtheria, tetanus, yellow fever, small pox. 1900–1930s Adaptation by mutation to ecologi- cal conditions by various organisms. 1927 H. J. Mueller accelerated mutations by X-rays; UV, radioctive emanations. Chemical mutations by ethyl methane sulpho- nate. Plant chromosomes doubled by colchicine, an alkaloid extracted from seeds and corms of the Meadow Saffron. 1929 Alexander Fleming accidentally discovered penicillin (anthropologists had much earlier descri- bed how primitive Micronesians rubbed moulds scrapedfromtreesintowoundstopreventfestering). 1920s Dyestuffs as antimicrobials. 1935 Sulphur drugs first developed by Bayer company in Germany. Diversified by May and Baker in UK. 1939 Cortisone isolated. 1939 Florey and Chain cultured P. notatum and isolated penicillin. Penicillin, subsequent antibiotics effective against pathogenic Streptococci, Staphyloccoci, Menin- gococci, Gonococci and Pneumonococci. 1930s/40s Chemical pesticides to attack malaria and typhus vectors. 1930s Frederick Hopkins reported first vitamins. 1955 Salk Polio vaccine developed. 1950–70s Crossing of sexually incompatible spe- cies by somatic hybridization (fusion of totipo- tent cells), embryo rescue, cell and tissue culture. 1953 Watson and Crick discovered double helix of DNA. 1973 First gene cloned. 1974 Cloned gene first expressed in a foreign bacterium. First hybridoma created. 1974 US Asilomar Conference proposed safety guidelines for rDNA research. 1976 Genentech—first specialist bioscience com- pany to exploit rDNA research. 1978 Genetic Manipulation Advisory Group (GMAG) created by UK government. 1978 US President’s Commission for Studies of Ethics in Medicine & Biomedical Research. 1980 US Supreme Court ruled microorganisms may be patented under US law 1980 Genentech’s public stock offering recorded highest ever price per share increase on New York stock exchange. Price/share rose from $35 to $89 in 20 min. 1980 Name ‘Genomics’ first used. 1981 Eighty new specialist bioscilbiotech com- panies formed in USA. 16 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18
  15. 15. 1980s/90s Rockafella Foundation and Interna- tional Rice Research Institute devised transgenic means to transfer pest resistances between wild and cultivated Oryza spp. Other transgenic food crops created. 1982 First rDNA vaccine for colibacillosis approved in Europe. 1982 Human insulin by rDNA approved in US and UK. 1992 US NIH Office of Alternative Medicine. 1994 US Dietary Supplement Education Act legally defined food/drug supplements: vitamins, minerals, herbs, amino acids, other plant meta- bolites and extracts. Late 1900s Increased understanding of (i) geno- mics—molecular characterization of species, (ii) bioinformatics—data banks and data processing for genomic analysis, (iii) genetic transforma- tions—various transgenic techniques to transfer genes between unrelated species, (4) molecular breeding—identification and translocation of useful biological properties by marker assisted selection, (5) diagnostics—identification of pathogens by molecular characterization, (6) improved immunology in humans, animals, plants and fish by recombinant DNA vaccines. 1998 Human embryonic stem cells first isolate from aborted fetus. 21st Century 2000 Human genome sequenced. 2001 US President’s Stem Cell Research Council. Estimated 1/3 of all Americans buy herbal remedies in place of prescription drugs. Herbal remedies offered for colds, influenza, gastrointestinal disturbances, rheumatoid and osteoarthritis, diabetes, hypertension, athero- sclerosis, asthma, depression, cancer and HIV/ AIDS. Difficulties of herbal medicines: inadequate standardisation. Nutraceuticals: foods purported to contain sub- stances pharmacologically beneficial. No food and drug laws in USA specifically relate to herbal remedies. References to related technology Biotechnology Ernst & Young. Annual regional biotechnology reviews.Oxford,UK:OxfordBusinessPublications. Bioscience Engineering: BBSRC review of bio- chem eng. (1999) Swindon, UK: (British) Bio- technology & Biological Sciences Research Council. Building long-term capability. (1996). Ottawa: Canadian Human Resources Study in Bio- technology Human Resources Development Canada. Leading in the next millennium. (1998). Ottawa: Rept of the National Biotechnology Advisory Committee Industry Canada. Annual reports of the NRC Biotech Research Inst. Ottawa: National Research Council of Canada. Biotechnology: opportunities & constraints. (1985). Ottawa: Intl Devt Res Centre (IDRC- MR 110e). European Union Council Directives on bio- technology. Rue de la Loi 200, B-1049, Brussels: EU. Good Manufacturing Practice, Position Statement on Genetic Modifications. British Inst of Food Sci and Tech, London: EU. Ismael Seraglio & Persley G J. Promethean Sci- ence: Agriculture, Biotechnology, Environment. CGIAR, World Bank, Washington DC. Ernst & Young. Focus on fundamentals: the bio- technology report. Ernst & Young L L P, NY. European Commission. Life sciences and bio- technology: A strategy for Europe. E C Public- ations, Luxembourg. Doyle, John J & Persley G J. Enabling safe use of biotechnology: EDS Series No 10. (1996). World Bank, Washington DC. FAO/WHO. Strategies for assessing the safety of foods produced by biotechnology. (1991). FAO, Rome. IFST(UK). Guide to food biotechnology. (1996). Inst Food Sci and Tech, UK. J of Pharmagenomics. Advanster Commu- nicatiosn. Edison, NJ. Biotech journals Biotechnology & Bioengineering. NJ: John Wiley. Enzyme & Microbiology Technology. Elsevier Press. Trends in Biotechnology. Elsevier. Biochemical Engineering Journal. John Wiley. Journal of Chemical Technology & Biotechnology. Elsevier Science Press. Food & Bioproducts Processing. Transactions of the Institute of Chemical Engineers UK. J Biotechnology. Elsevier. Bioprocess & Biosystems Engineering. Springer. Biotechnology Progress. American Chemists’ Society. BioCanada 2000. Montreal: Montreal Business Magazines. Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18 17
  16. 16. Historical Gribbin, J. (2002). Science: a history. Penguin Books, UK. Mees, C.E.K. (1947). The path of science. New York: John Wiley. Boorstin, D.J. (1998). The seekers. New York: Random House. Boorstin, D.J. (1993). The creators. New York: Vintage Books, Random House. Boorstin, D.J. (1985). The discoverers. New York: Vintage Books, Random House. Rose, S. (1976). The chemistry of life. UK: Penguin Books. Dixon, B. (1976). What is science for? UK: Penguin Books. Jacob, H.E. (1954). Sechstausend Jahre Brot. Hamburg: Rowohit Verlag GMBH. Corran, H.S. (1975). A history of brewing. Lon- don: David and Charles. Walton, J., Barondess, J.A., & Lock, S. (Eds.). (1994). The Oxford medical companion. Oxford University Press. Duffin, J. (1999). History of medicine. University of Toronto Press. Porter, R.W. (1997). The greatest benefit to mankind: a medical history of humanity. New York: W.W. Norton & Co. Bynum, W.F., & Porter, R. (Eds.). (1993). Companion encyclopaedia of the history of medi- cine. London: Routledge. Sonnedekker, G. (Ed.). (1976). Kremers and Urdang’s history of pharmacy Philadelphia: Lippincott. De Burgh, W.G. (1947). The legacy of the ancient world. London: McDonalds & Evans. Tacitus, Cornelius. (1956). The annals of Imperial Rome. Penguin Classics. Livius, Titus. (1960). The early history of Rome. Penguin Classics. Tannahill, Reay. (1973). Food in history. New York: Stein & Day. Root, Waverly. (1980). Food. New York: Simon & Shuster. Porter, R., & Teich, M. (Eds.). Drugs and narcotics in history. Cambridge University Press. Magner, L.N. (1994). A history of the life sciences. New York: M. Dekker. Porkert, M., & Ullmann, C. Chinese medicine: its history, philosophy and practice. New York: W. Morrow. By this author: Joseph H Hulse Science, Agriculture and Food Security. (1995). National Research Council of Canada. Ethical issues in biotechnologies and interna- tional trade. (2002). Journal of Chemistry, Tech- nology and Biotechnology, 77, 607. Opportunities for industrial bioengineers. (2001). Food Science and Technology, 15, 34; Opportu- nities for industrial bioengineers. (2002). Food Science and Technology, 16, 34. Biotechnologies: new homes for an old dilemma. (1984). Journal of the Canadian Institute of Food Science and Technology, 17(3), iii. Any Suggestions? Articles published in TIFS are usually specially invited by the Editors, with assistance from our International Advisory Editorial Board. However, we welcome ideas from readers for articles on exciting new and developing areas of food research. A brief synopsis of the proposal should first be sent to the Editors, who can provide detailed guidelines on manuscript preparation. Mini-reviews focus on promising areas of food research that are advancing rapidly, or are in need of re-review in the light of recent advances or changing priorities within the food industry. Thus they are shorter than conventional reviews, focusing on the latest developments and discussing likely future applications and research needs. Features are similar in style to mini-reviews, highlighting specific topics of broad appeal to the food science community. The Viewpoint section provides a forum to express personal options, observations or hypotheses, to present new perspectives, and to help advance understanding of controversial issues by provoking debate and comment. Conference Reports highlight and assess important developments presented at relevent conferences worldwide. TIFS also welcomes Letters to the Editor concerned with issues raised by published articles or by recent developments in the food sciences. All Review-style articles are subject to editorial and independent peer review by international experts in the appropriate field. 18 Joseph H. Hulse / Trends in Food Science & Technology 15 (2004) 3–18