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hurdle will be in the latter area. The technological hurdles will be formi­ dable but will not limit what happens: once the basic ideas are available, the technology will be developed. The unique part of biotechnology will be to imagine what the possibilities are. There was a discussion in several of the groups on the problems of intro­ ducing a novel science into a social and economic context. What biotech­ nologists are learning on this matter is not novel, although that does not make it any less important or difficult. People in the development of elec­ tronics and computers, in the pharmaceutical industry, and in many other types of industry that have grown from university research have had to face these problems in the past. It is the old situation of having to reinvent the wheel again and again. There is one aspect on which biotechnology seems to have handled this inherent difficulty better than some of our predecessor technologies: the people in the biotechnology companies by and large take a rather academic approach to free communication with one another at meetings such as this and open publication of many of their basic findings in the literature. This seems unique and certainly is different from the experience of the recent Silicone Valley Industry, which in other ways tries to emulate an academic environment, but not in open and free publication.

Inhaltsverzeichnis

Frontmatter

Introduction

Abstract
We need to place this workshop report into a broad context, considering various aspects of biotechnology which differentiate it from more narrow descriptions of industrial microbiology (including food technology, industrial fermentations, and the pharmaceutical industry, which combined have a history of more than 100 years). The various aspects of biotechnology include a) the introduction of recombinant DNA and cloning techniques that allow a more rational and planned (that is, engineering) approach to production problems than was possible in the past. This new logical approach is in marked contrast to earlier use of genetics to isolate high production mutants in the fermentation industry, the pharmaceutical industry, and in agricultural plant and animal husbandry. b) The new genetic engineering expands beyond the possibilities of product production in the factory. It is clearly understood that it will have an enormous impact on human medicine, on animal medicine and meat production, and on agronomy and the production of useful agricultural plants. c) We need to pay attention to more than merely the technological questions. As introduced by Blöcker and Frank (this volume), we need to be concerned about how the new products of biotechnology will affect the human community; and we must be especially concerned about how this technology will affect lesser developed nations.
S. Silver

Technical Approaches

Group Report
Abstract
In evaluating the available technical resources and future needs for the manipulation of genes and cells for use in industry, medicine, and agriculture one has to consider the need for increased understanding of biology as well as the identification and achievement of very specific objectives. To this end, gene synthesis, mutagenesis, protein structure modeling and engineering, gene expression (transcription, translation, and post-transcriptional processing), host-vector systems, gene isolation, reverse genetics (transplacement), and applications of immunology were reviewed. In many of these areas the technology is very sophisticated (17, 21), in others it is lacking or is understood to such a limited degree that it cannot be applied in a predictable way. Most, if not all, of the technology is the result of academic investigator-initiated research. It is essential for future developments in molecular genetics that support of this non-applied research is not diminished.
M. Smith, W. M. Barnes, M. van Montagu, H. Blöcker, P. Weglenski, U. Krawinkel, G. Winter, H. Lehrach, S. J. Wodak, R. Marquardt

Cloning and Expressing Genes for Clinically Useful Proteins

Abstract
Clinically useful proteins come in all shapes and sizes and while some are extremely rare in natural occurrence, others are quite abundant. Some have complex modifications to their primary sequence which are necessary for their function. As a result, the methods used for the isolation of the genes encoding these proteins are diverse and in many cases expression of the proteins requires the development of novel host vector systems. This review will not try to cover all the possible alternative cloning and expression methods available but will give the reader an insight into the strategies frequently used to clone and express genes of clinical interest while selecting some examples to illustrate these approaches.
R. M. Kay, R. Kaufman, P. Schendel, K. Turner, R. Kamen

Synthetic Genes

Abstract
Chemically synthesized DNA fragments are versatile tools in modern bioscience. They are nowadays routinely used not only in recombinant DNA projects as probes, primers, linkers, and adaptors, but also in the construction of complete genes. The present technology for total gene synthesis is described. We believe that further improvements in the methodology will make the present instrumentation for DNA synthesis obsolete, enable us to circumvent, when desired, techniques such as site-directed mutagenesis and open up better possibilities, e.g., in the design of proteins. In addition, we consider social responsibilities of DNA chemists.
H. Blöcker, R. Frank

Protein Engineering

Abstract
Site-directed mutagenesis of a gene allows the sequence of the encoded protein to be altered, and thereby its functions. The technology of making mutants and engineering new properties in proteins will be reviewed.
G. Winter, P. Carter, H. Bedouelle, D. Lowe, R. J. Leatherbarrow, A. R. Fersht

Microbiology and Industrial Products

Group Report
Abstract
The selection of problems for discussion in the group was based on the background papers and the expertise of the people present. Therefore the topics selected should not be considered a priority list with regard to the field in general; especially some aspects in biochemical engineering and industrial fermentation were underrepresented. In view of industrial application it was felt that existing curricula in basic science at universities and organizational barriers in industry have not encouraged the communication between different disciplines now needed to establish complex biotechnological processes of the next generation. An integration of the knowledge available in several fields and a systems approach will eventually save time and money and yield more economical processes than attempts to optimize single stages only. To improve communication and overcome language barriers between disciplines, training grants for postdoctorates, visiting scientists, etc., should be made available to allow work for a period of time in a laboratory primarily concerned with a different discipline. In the future, teaching of major subjects such as genetics, microbiology, biochemistry, and biochemical engineering should also be complemented by some introduction into the other sectors of biotechnology.
M.-R. Kula, Y. Aharonowitz, O. M. Neijssel, J. D. Bu’lock, H. Sahm, A. M. Chakrabarty, J. Sobieszczański, D. A. Hopwood, U. Stahl, B. Mattiasson, K. N. Timmis, J. G. Morris

Fermentation Products: Physiological and Bioenergetic Considerations

Abstract
The overproduction of substances by microbial cultures is discussed in a bioenergetic context. Since many fermentation products are generated by energy-yielding reactions, it is clear that the rate of energy consumption of a cell will influence the rate of product formation. It is shown that the nature of the growth environment influences to a great extent the magnitude of these energy-consuming reactions. On the other hand, the energetic efficiency of the energy-generating reactions can be reduced and this will lead, assuming the same rate of energy consumption, to an increased rate of product formation. Another class of products, in particular proteins, can only be produced by energy-consuming reactions. Therefore, the extra energy consumption caused by the overproduction of proteins is in direct competition with the energy consumption that the cell requires for maintenance and growth. The physiological implications of this metabolic conflict are discussed and it is suggested that this type of overproduction will be inherently unstable, unless the overproduction of a protein increases the fitness of the producer organism.
O. M. Neijssel, D. W. Tempest

Bioactive Microbial Secondary Metabolites

Abstract
Microorganisms have become a veritable resource of biologically active compounds. Thousands of such metabolites have been identified thus far and show a diversity of chemical structure, complexity, and physiological function. The types of bioactivity characterized have depended ultimately on the operational approach taken for their detection and isolation. Traditionally, the ability to antagonize the growth of bacteria, fungi, viruses, and other forms of life has been the major requirement. Therefore, it has resulted in the isolation of metabolites possessing mainly antibiotic activity. However, this trend is now being changed. It has become possible to design screening procedures that turn up active molecules having entirely different properties. The availability of powerful tools for increasing genetic variability, appreciation of the physiological characteristics of the producing organisms, as well as advances in biochemical understanding have been of enormous importance in developing new microbial strains for industrial application and basic research and in allowing microbial cells to be subverted for the purpose of making novel metabolites. However, the question of why microorganisms make all these metabolites remains unanswered. Little is known about the natural role of these important compounds. They have, therefore, been termed “secondary metabolites” so as to distinguish them from the primary metabolites of the cell that are known to be essential for growth of the organism.
Y. Aharonowitz, G. Cohen

Technological Processes for Biotechnological Utilization of Microorganisms

Abstract
When developing new processes for production of various biochemicals the creation of the organism, often by gene technology, is a very important step which must be accompanied by development of cultivation as well as downstream steps. There is a lot to gain by treating the whole process, from creation of the organism to isolation of the product, as one process that has to be optimized in the overall mode.
The present paper deals with recent developments in process technology for utilizing microorganisms and with some efforts to integrate bioconversion and upgrading.
B. Mattiasson

Animals and Medicines

Group Report
Abstract
In the discussion of the impact of gene technology, synthetic peptides, studies on protein structure, and new immunological tools (such as monoclonal antibodies) in the area of animals and medicines, we identified an underlying theme which can be described as follows. At present new tools are rapidly being applied to biological systems which have been extensively defined at the biochemical level (e.g., blood homeostasis, many peptide hormones). The future trends can, however, already be discerned in which the isolation of new factors tells us more about the original biological system (e.g., discovery of new peptide hormones on ACTH-precursors; biological modifiers in the blood pressure regulation cascade; interferon gene family members; dissection of antigenic sites of pathogens). The further rapid advancement of this field (which is to be expected) will result from intensive interdisciplinary research in which the main emphasis will rest at the level of basic research on biological systems (complex systems) and protein structure.
J. Collins, H. Betz, D. J. Rowlands, J. E. Davies, H. Schaller, W. Fiers, G. Siewert, E. Paoletti, A. E. Sippel, E. Pfaff, E. F. Wagner

Vaccines - the Synthetic Antigen Approach

Abstract
Technological and conceptual advances in the last few years have opened up a variety of new avenues towards improvement of existing vaccines and providing vaccines against diseases for which there is no protection currently available. These new approaches are discussed with particular emphasis on those involving synthetic peptide antigens.
D. J. Rowlands

A Modern Approach to Live Vaccines: Recombinant Poxviruses

Abstract
A technique for preparing live recombinant vaccines is described. The technique is a blend of old and new technologies. Vaccinia virus, used for almost two hundred years in the immunoprophylaxis of smallpox, has been engineered by recombinant DNA technologies to express foreign genetic information derived from heterologous pathogens. This recombinant live vaccine virus has been shown to elicit important immunological responses to these foreign antigens on inoculation of the recombinant virus into animals. Significantly, a number of studies have shown that vaccination of laboratory animals with these recombinant viruses results in protecting these animals against disease on subsequent challenge with the heterologous infectious agent. Vaccinia virus recombinants expressing the influenza virus hemagglutinin, the herpes simplex virus glycoprotein D, the hepatitis B virus surface antigen, the rabies virus glycoprotein, and a malarial parasite antigen are described and the biological properties of these recombinant viruses as live immunogens are detailed. A brief description of the problems and future prospects is included.
E. Paoletti, M. E. Perkus, A. Piccini, B. R. Lipinskas, S. R. Mercer

The Future Role in Medicine of Proteins Made by Genetic Engineering

Abstract
Most of the efforts in the pharmaceutical industry are directed toward human medicine, but quite often these concepts and breakthroughs also find parallel applications in veterinary medicine. However, we will not discuss here those possible applications to veterinary science which are not primarily directed towards alleviation of disease such as the possible use of growth hormones in animal husbandry. The term “genetic engineering” will be used to designate the cloning of genes in a heterologous genetic context, and especially the efficient expression of these cloned genes in heterologous cells. Therefore, the use of chemically synthesized peptides in medicine will not be further considered here. It is generally accepted that the cutoff for economical chemical synthesis of peptides is about 20–30 amino acids; above that, genetic engineering methodology becomes the method of choice.
W. Fiers

Some Applications of Modern Immunological Techniques

Abstract
There are many innovative applications for immunological techniques in a wide variety of fields. To cover them all is far beyond the scope of this brief summary. I rather concentrate on the description of some techniques that have become important for clinical and biotechnological research in recent years: a) hybridomas producing antibodies for the identification and purification of molecules and cells of interest; b) genetically engineered antibodies; c) cell sorting; and d) bone marrow transplantation. These techniques are interrelated in that the latter three are dependent on the achievements made in the monoclonal antibody field.
U. Krawinkel

Gene Transfer into Mouse Stem Cells

Abstract
The various approaches that can be used to introduce genes into embryos and stem cells will be reviewed. In particular, the results obtained using DNA injection and retroviral vectors will be summarized and the potential of these systems discussed.
E. F. Wagner, U. Ruether, C. L. Stewart

Plants and Agriculture

Group Report
Abstract
The selection of “improved” plants by man and the practice of agriculture are thousands of years old. For many species, selection and careful culture have produced remarkable increases in harvestable products to provide man with food, fuel for cooking, paper, fiber, energy, and a range of special chemicals including medicinal compounds and wood for housing, construction, etc. The need for continuation of the improvements in many species, for adaptation of plants to new industrial processes and for manipulating agriculture to the changing patterns of societies and economies is greater than ever before.
R. B. Flavell, W. Barz, W. J. Peacock, J. E. Beringer, H. Saedler, P. Broda, F. Salamini, D. E. Eveleigh, P. Starlinger, K. Hahlbrock, E. Weiler, R. Kahmann, M. Zenk

Plant Gene Engineering and Plant Agriculture

Abstract
Many plant breeders feel there is little prospect that genetic engineering will make any real contribution to plant improvement programs. We cannot agree, as it is already clear that recombinant DNA technology will make impacts on plant production systems. Diagnostic tools will provide increased power to many selection schemes and increased accuracy in the selection or appropriate parents in breeding programs. Genetic engineering should also make direct contributions to plant improvement by providing additional means of introducing specific genes to the genetic structure of a cultivar. Gene addition should extend the life of many of our most efficient cultivars and enable them to be used in different and more marginal environments. It should enable a plant breeder to respond to yield limitation in a shorter time. It may also significantly reduce the scale of a plant breeding program. Time and scale of operation are probably the principal factors in determining the effectiveness of any plant improvement effort.
All the components of a gene transfer system are presently in place for only one or two commercial crops. However, it should be possible to have effective systems in each of the major crop species in the near future. Gene transfer technologies will increase the range of variation available to a plant breeder for any given crop species and will provide opportunities for quite novel adjustments to the workings of a genome, adjustments which would not have been possible by classical breeding and selection schemes. We feel sure that the analytical power of recombinant DNA technology will also help to dissect the apparent complexity of many of the major agronomic physiological characteristics so fundamental to successful plant production. We may thus be able to provide substantial yield increases in even the most well developed crop species.
W. J. Peacock, E. S. Dennis

Secondary Products

Abstract
Secondary plant products are of great commercial interest in chemical, pharmaceutical, cosmetic, food, and other industries. For the production of particularly valuable compounds, cell suspension cultures in bioreactors have the potential to replace intact plants and complement chemical syntheses, although only a few industrial applications are so far in or near operation. Another area of interest is the relation of secondary products to nutritional quality, yield, and storage properties of crop plants (e.g., substances involved in disease resistance). Despite an urgent need for a better understanding of the physiology, biochemistry, and genetics of secondary product formation, it is foreseeable that this field will soon benefit from the application of gene transfer and other biotechnological methods.
K. Hahlbrock

Plant-Microbe Interactions

Abstract
All plants are exposed to extremely large numbers of microorganisms; some are pathogenic and some beneficial. The potential damage that can be caused by pathogens appears to be held in check by beneficial microorganisms, many of which are probably unknown to us. Future exploitation of such interactions will be as dependent on a better understanding of the biology of plant-microbe interaction as on developments in biotechnology. Plant nutrition is influenced by nitrogen-fixing microorganisms, mycorrhizal fungi, and possibly other microorganisms. These existing symbioses can be exploited to improve the activities that we understand sufficiently well and to introduce novel functions into the symbionts. Whether the production of growth-promoting substances by microorganisms can be exploited for crop production or not remains to be established.
J. E. Beringer

Importance of the Rhizosphere in Plant-Microbe Interactions

Abstract
Harmful interactions, beneficial interactions, and problems of commercial exploitation all occur. Future exploitation of such interactions will be as dependent on better understanding of the biology of plant-microbe interactions as on developments in biotechnology. In my opinion, more attention should be placed on the details of the rhizosphere of microorganisms and their role in plant life. In addition, more stress should be placed on methods which should be used for better recognition of the biology and ecology of plant-microbe interactions. We should come to a better understanding of this problem and try to utilize this information in practice in order to direct the growth and development of plants.
J. Sobieszczański

The Production and Utilization of Lignocellulose

Abstract
Many poorer countries depend for energy and chemicals for development upon renewable resources. Biotechnology has a part to play in improving production of biomass and in possible processes for its conversion to fuels and chemical feedstocks. Economic, political, social, and environmental considerations as well as scientific and technological advances will determine how much progress is made. Although there is a diversity of materials, ranging from wood and sugarcane bagasse to municipal solid waste and animal waste, there are some unifying features. There is the need to understand the biological attack of lignin and of crystalline cellulose and the design of processes such as solid-substrate fermentations that would be applicable to developing countries.
P. Broda

Social and Ethical Considerations for Biotechnology

Abstract
Modern biotechnology has provided techniques that allow the planned and directed modification of living organisms: the realization of the concept of biological factories, and of changing certain forms of plant and animal life to suit man’s needs, is about to occur. However, when a technical revolution of some substance occurs, there are always aspects other than the direct benefit to mankind that have to be considered. In all cases a risk/benefit ratio should be evaluated.
J. E. Davies

Backmatter

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