|Eco-restructuring: Implications for sustainable development (UNU, 1998, 417 pages)|
|Part I: Restructuring resource use|
|3. Ecological process engineering: The potential of bio-processing|
Four main fields of technical application (apart from food and beverages) are well known. These are health care, agriculture, environmental remediation, and industrial materials processing. These are discussed briefly in the following pages.
Health care (pharmacology and medicine)
The health-care field of biotechnology includes the production of vaccines, hormones (such as insulin), therapeutics, diagnostics, and antibiotics via conventional process routes, such as cell cultures, using natural organisms. Antibiotics are normally made in this way. For instance, penicillin, the first antibiotic, is produced by a fungus. Increasingly, however, "modern" pathways are being exploited, based on genetically engineered organisms (GEOs). These GEOs either lack certain genes or contain genes from other organism.1 As a result they have properties not found in the natural versions of those organisms.
Editor's note: Most of the early applications of genetic engineering technology have been in this field, owing to the high value of some pharmaceutical products.2 For example, Eli Lilly began producing human insulin by recombinant DNA techniques in 1982. Interferon, human and animal growth hormones, and monoclonal antibodies are examples of early applications. Public attention is usually drawn to the advertised benefits of these innovations for society, especially the possibility of sharply cutting the costs of important categories of drugs. Most of these short-term benefits have been consistently overestimated, and the length of time needed to take a new drug or diagnostic technique through the tedious and complex approval process is consistently underestimated. Nevertheless, by the late 1980s several biotechnology firms - especially Amgen - had developed successful and profitable products and a number of others had been sold to international pharmaceutical giants.
Agriculture and food technology
Older agriculture shaped natural plants and animals to human uses by means of breeding techniques. The modern branch of agriculture uses chemicals derived from biological materials (such as hormones and plant growth regulators, single cell protein, vaccines), microbial cultures, and new plants and animals created deliberately by genetic engineering modifications of existing organisms by recombinant DNA methods. Potential and obviously desirable future applications of genetic engineering are to introduce nitrogen fixation capability and/or disease resistance into important crops, such as potatoes, corn, or rice.
Public debate reflects serious safety concerns here, too.
Environmental biotechnology is understood in a broad sense as the application of biotechnologies - mainly micro-organisms - to the solution of existing environmental problems, including the treatment of sewage, waste water, and even soil decontamination. Early applications include biogas systems. Genetically engineered organisms are also increasingly used in this field, resulting in the same public concerns about safety mentioned above.
Industrial biotechnology is an established field, including cheese-making, winemaking, the brewing of beer, and the production of baker's yeast, vinegar, alcohol, acetone, acetic acid, citric acid, etc. from carbohydrates and sugars, mainly by fermentation. GEOs are not yet being applied in this area, although it would seem to be an inevitable evolutionary development.
It is quite important for the evaluation of biotechnologies to consider the normal life cycle of technologies. The different stages of development are marked by the production of molecules of increasing complexity (e.g. bulk chemicals, single cell protein, drugs).
A rather visionary, more distant future stage can be denoted "eco-technology," or simply "eco-tech." The name is intended to convey the idea that biotechnology eventually begins to substitute for more conventional technologies in a wide range of applications, resulting in significant environmental benefits and a much closer approach to long-term sustainability.
Scientifically the advantages of bio-processing over chemical processing can generally be characterized as follows:
- big-catalysts are highly active, specific, and selective; their regeneration is easier than in the case of chemical catalysts; there are no environmental problems as with heavy metals;
- reaction conditions are mild (temperature, pressure, and also concentrations);
- internal energy is supplied by energy-enriched compounds, e.g. ATP, which are formed during metabolism;
- impure, diluted, and inactive raw materials can be used, owing to the high specificity and selectivity of big-catalysts;
- big-products are biodegradable in natural cycles.
The competitiveness of biotechnologies in comparison with chemical technologies is discussed later in this chapter. The most competitive opportunities for biotechnology, at present, lie in the domain of high-price/low volume "specialty" products. However, increasing success in this domain, together with rising prices for petroleum and other fossil hydrocarbons, suggests that opportunities will gradually increase over coming decades in the domain of low-price/high-volume "commodity" products.
Two observations apply to biotechnologies in general. In the first place, to produce highly complex and specific products such as pharmaceuticals, or to degrade toxic substances in the environment, the biological path is already clearly superior to the chemical path in many cases. A similar competitive break-point can be expected in the near future in several other cases, where bio-processing becomes yearly more competitive. To be more specific, the most successful current applications of big-processes are as follows:
- the production of foods (e.g. cheese, yogurt, soya sauce) and beverages (wine, beer);
- the production of complex molecules on the industrial scale for use in health care for humans, animals, and plants (pharmaceuticals and therapeutics, antibiotics, proteins, steroids, etc.);
- the degradation/purification of wastes and toxic substances in the environment (sewage, industrial wastes, water treatment, etc.);
- sequential reactions in one-step processes (e.g. the production of steroids), highly selective stereo-specific conversions, etc.
There are other domains where the advantages of "biologicals" compared with "chemicals" are likely to be established soon. These include the reclamation of soil, the recycling or sequestration of carbon dioxide, the production of biofuels from waste agricultural or forest biomass, the creation of new and more productive plants capable of surviving in different climates, resisting diseases, etc. The beneficial products of bio-processing will surely increase in the next decade.
A second observation is that process economics for biotechnological products (thus far) suffer generally from the fact that they depend on growth cultures. The latter involve lower concentrations, higher water content, and, consequently, higher energy requirements for separation and purification than does chemical processing, in general. The need for more sophisticated equipment, and more highly educated technicians, also contributes to the current competitive disadvantage of biotechnologies as compared with chemical processing.
Thus, despite their potential benefits in terms of long-term sustainability, most big-processes are not yet economically competitive. Biotechnology is not expected to become competitive on a wide range of fronts before the year 2030 (OECD 1989). Even this forecast will prove overoptimistic unless efforts toward commercialization are accelerated, especially by strengthening process engineering sciences (Moser 1994). Research programmes in big process engineering have been recently stepped up in Japan (1992), the United States (1992), and Europe (1993).
In the following section, the status of the various biotechnologies is considered in more detail.