EFB Task Group on Public Perceptions of Biotechnology

Environmental Biotechnology

June 1995

• Outline
• The State of Environmental Biotechnology
• Bioremediation
• Environmental Protection
• Pollution Detection and Monitoring
• New Biotechnology - the Use of GMMOs

For more than a century, biotechnology has acted as a vital buffer between people, pollution and the environment. The ever-increasing stresses we inflict upon the world's ecosystems mean that this field is becoming ever more important. It may be that biotec hnology will not only be able to help clean up the messes we make, but also prevent them ever happening in the first place.

This briefing paper reviews the various areas of environmental biotechnology together with their related issues and implications. The overall aim is to provide balanced information and advance public debate.

This paper results from the combined contributions of scientists, industrialists, and governmental and environmental organisations across Europe. It is intended to supply information and does not represent the views or policy of the European Federation of B iotechnology or any other body.

BIOTECHNOLOGY

Biotechnology is "the integration of natural sciences and engineering in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services" (EFB General Assembly, 1989). Environmental biotechnology is the application of these processes for the protection and restoration of the quality of the environment.

SCOPE

Environmental biotechnology was used to maintain and restore environmental quality long before the term existed. Municipal sewage treatment plants and filters to purify town gas were developed around the turn of the century. They proved very effective altho ugh at the time, the cause for their action was unknown.

The first methods of sewage treatment simply let the offending materials flow along open ditches. Forced aeration was an innovation that markedly improved the efficiency of the purification of the wastes. By the 1930s, it was becoming apparent that biologic al processes were involved. With this knowledge, civil engineers worked with biologists to develop more efficient biological waste digestion systems. These processes are essentially how all sewage, and much industrial waste water is now treated. They will c ontinue to play a vital role as long as sewage is generated - especially as world population and industrialisation continue to increase.

During the 1970s a much deeper understanding grew of the biological processes involved in waste treatment. Desire from industry for compact, high throughput treatment plants led to the development of anaerobic biodigesters; developed by microbiologists work ing with mechanical engineers.

Different kinds of microorganisms have now been identified as being particularly suitable for different situations. In recent years systems have been developed to cope with particular waste treatment needs. Combined aerobic/anaerobic biodigesters are coloni sed with strains of microorganisms that have a particular penchant for the substances in the waste. Before such bioreactors, the wastes from industries largely went untreated straight into the environment, or a best, to already burdened municipal treatment works.

Bioengineers are now producing increasingly specific, efficient bioreactors as they come to understand and select the organisms best suited to a range of different waste streams. A significant industry has developed providing such tailored treatment plants to companies around the world.

But the uses of biotechnology extend beyond cleaning up dirty water. Recently, biotechnology has began to remediate (make better) damage caused by chemical or physical production processes in industry. Further to repairing the damage, new developments in bi otechnology are making it possible to replace harmful processes with less environmentally damaging ones. The advantages of environmental biotechnological methods come from millions of years of evolution. Biological systems are almost always more efficient t han other methods, producing less secondary waste and using less energy; so not contributing to further environmental problems.

Most current environmental biotechnology is remedial in nature, cleaning up pollution already inflicted on the environment. Naturally occurring microorganisms are used to increase the rate of naturally occurring remediating processes. These microorganisms m ay already exist within the local environment or be introduced from elsewhere. New applications are constantly being discovered from the vast, little-exploited resource of organisms that can contribute to restoring and maintaining the environment.

Cleaning up waste does however, circumvent a basic issue. The fact that there is waste implies that there are industrial processes which are inefficient or "non-ideal." The goal must be to reduce waste at source by improving these processes. Economics conti nue to drive industry towards more efficient processes, and government levies can drive companies to develop less environmentally damaging processes. The second law of thermodynamics explains that all closed systems tend towards disorder, from this it follo ws that there will fundamentally always be some waste from any process. Modern biotechnology can help to minimise this waste and also its impact on the environment.

There are different approaches to environmental biotechnology from other sectors of biology. Agricultural biotechnology is developing plant varieties that either require lower levels of artificial fertilisers or that have increased resistance to viruses, fu ngi and other disease agents. Farmers' dependence on pesticides and fertilisers could thus be reduced, with consequent benefits to the environment. Animal biotechnology is aiming towards higher levels of production from fewer animals, especially important i n regions where waste from intensive animal rearing is leading to serious soil and water pollution. Microbial biotechnology is developing the genetic modification of naturally occurring organisms - enabling them to degrade pollutants that previously they co uld not, or only inefficiently, deal with.

THE STATE OF ENVIRONMENTAL BIOTECHNOLOGY

Biotechnology can be used to detect, prevent and remediate the emission of pollutants into the environment in a number of ways(1). Solid, liquid and gaseous wastes can be modified, either by recycling to make new products, or by purifying so that the end pr oduct is less harmful to the environment. Environmental damage can be reduced by replacing chemical materials and processes with biological technologies. While research has, to date, concentrated on cleaning previously polluted areas, it is likely that dete ction, remediation and prevention of environmental damage will play increasingly important roles in the future. In this way environmental biotechnology can make a significant contribution to the sustainable development of technology.

BIOREMEDIATION

The degradation of pollutants by microorganisms is the basis of bioremediation. Under normal circumstances, microorganism activity is often limited by levels of nutrients and/or oxygen. In such situations, bioremediation is effected by supplementing the lim iting factors.

Environmental protection and remediation presently combine biotechnological, chemical, physical and engineering methods. The relative importance of biotechnology is increasing as scientific knowledge and methods improve. Its lower requirements for energy an d chemicals, combined with lower production of secondary wastes, make it an increasingly desirable alternative to more traditional chemical and physical methods of remediation.

Waste water and industrial effluents: Microorganisms in sewage treatment plants remove the more common pollutants from waste water before it is discharged into rivers or the sea. Increasing industrial and agricultural pollution has led to a greater need for processes that remove specific pollutants such as nitrogen and phosphorus compounds, heavy metals and chlorinated compounds. New methods include aerobic, anaerobic and chemical-physical processes in fixed bed filters and bioreactors in which the materials and microbes are held in suspension.

Drinking and Process Water: Abundant supplies of water are vital for modern urban and industrial development. By the turn of this century, it is estimated that two thirds of the world's nations will be water stressed -using clean water faster than it is rep lenished in aquifers or rivers. A very important aspect of biotechnology is therefore its potential for the reclamation and purification of waste waters for re-use. Public concern has also increased over the present quality of drinking water. Not only does water need to be recycled in the development of sustainable use of resources, overall quality must also be improved to satisfy consumers. In many agricultural regions of the world, animal wastes and excess fertilisers result in high levels of nitrates in dr inking water. Biotechnology has provided successful methods by which these compounds can be removed from processed water before it is delivered to customers.

Air and waste gases: Originally, industrial waste disposal systems were based on cheap compost filled filters that removed odours. However, slow processing rates and the short life of such filters drove research into better methods. Most recently, the selec tion of microorganisms that are more efficient at metabolising pollutants has led to better air and gas purifying biofilters.

Soil and land treatment: This can be effected in a number of ways, either in situ or by mechanically removing the soil for treatment elsewhere. In situ treatments include adding nutrient solutions, introducing microorganisms and ventilation. Ex situ treatme nt involves excavating the soil and treating it above ground, either as compost, in soil banks, or in specialised slurry bioreactors. Bioremediation of land is often cheaper than physical methods and its products are largely harmless. Its action can however , be time-consuming, tying up capital and land.

Using environmental biotechnology research, it has become possible to treat soil contaminated with mineral oils. Biological degradation of oils has proved commercially viable both on large and small scales, and in situ and ex situ. Commercial viability is i mportant if we are to see our environment improved. But for the long term, remediation must not be depended upon at the expense of developing less environmentally damaging processes.

Solid waste: Composting of solid waste by conversion to less toxic, more stable materials, is one of the oldest and best known applications of environmental biotechnology. New approaches include decomposition within landfill sites, composting in open piles and bioreactors. Anaerobic digestion in these produces biogas usable as an energy source.

PROTECTION

Progressively more industrial companies are developing processes with reduced environmental impact. There is a pervading trend towards less harmful products and processes; away from "end-of-the-pipe" treatment of waste streams. Many companies and institutio ns have devised quantitative methods by which they can monitor their influence on the environment.

There are many ways in which industry can use biotechnology to prevent damage to the environment:

End-of-pipe processes employ microorganisms to purify waste streams so that the effluent can be discharged without harm into the environment. Their shortcoming is of curing only the symptoms of "unfriendly" processes. The main example of this form of enviro nmental protection is sewage treatment. Sewage itself is unavoidable but the way in which it becomes mixed with rain water runoff and industrial wastes creates problems. Comparatively little effort is spent in reducing the volumes of contaminated waste wate r needing treatment.

Added-value processes involve the conversion of wastes into useful products. For example, bacteria are used to produce catechol (an important starting substance in the synthesis of other compounds) from waste streams contaminated with phenols. Another examp le is the production of animal feed from the wastes of human food processing plants. This decreases the quantities of waste whilst creating useful products.

Process innovation, for example in leather processing, has introduced enzymes to replace harsh chemicals traditionally used for cleaning the hide. In textile production, enzymes have superseded chemicals for bleaching, including the "stone washing" of jeans . Chlorine consumption by the pulp and paper industry may soon also be reduced considerably by the use of enzymes.

The grease and protein digesting enzymes in washing powders significantly reduce the quantity of detergents needed for a given washing effect. They also mean that the washing temperature can be reduced - lowering the temperature 20</p>C saves more than a th ird of the energy used by the machine. Since, in many Western European countries up to 5% of household energy consumption is for washing, these molecules can make a significant contribution to energy conservation.

New biomaterials development leads to the manufacture of materials with reduced environmental impact, such as biodegradable plastics.

The industrial processes above frequently involve the use of enzymes, either produced by living organisms or isolated from them; and increasingly from genetically modified organisms. Enzymes work as biological catalysts, they are highly efficient and have n umerous advantages over non-biological catalysts. They are non-toxic and biodegradable, work best at moderate temperatures and in mild conditions, and have fewer adverse side effects than traditional methods because they are highly specific. Production meth ods that employ enzymes are not only cleaner and safer compared with other methods, but also more economic in energy and resource consumption. Their specificity does however mean that it is not always easy to find the appropriate enzyme for a given applicat ion. Enzymes are already widely employed in industry and have been for many years. New techniques and approaches to protein design and molecular modelling are enabling researchers to develop novel enzymes active at high temperatures, in non-aqueous solvents and as solids.

DETECTION AND MONITORING

A wide range of biological methods are already in use to detect pollution incidents and for the continuous monitoring of pollutants. Long established measures include: counting the number of plant, animal and microbial species, counting the numbers of indiv iduals in those species or analysing the levels of oxygen, methane or other compounds in water. More recently, biological detection methods using biosensors and immunoassays have been developed and are now being commercialised.

Biosensors are a combination of biological and electronic devices -frequently in the form of an electronic type chip. The biological component might be simply an enzyme or antibody, or even a colony of bacteria, a membrane, neural receptor, or an entire org anism. Immobilised on a substrate, their properties change in response to some environmental effect in a way that is electronically or optically detectable. It is then possible to make quantitative measurements of pollutants with extreme precision or to ver y high sensitivities. The sensors can be designed to be very selective, or sensitive to a broad range of compounds. For example, a wide range of herbicides can be detected in river water using algal-based biosensors; the stresses inflicted on the organisms being measured as changes in the optical properties of the plant's chlorophyll.

Immunoassays use labelled antibodies (complex proteins produced in biological response to specific agents) and enzymes to measure pollutant levels. If a pollutant is present, the antibody attaches itself to it; the label making it detectable either through colour change, fluorescence or radioactivity. Immunoassays of various types have been developed for the continuous, automated and inexpensive monitoring of pesticides such as dieldrin and parathion. The nature of these techniques, the results of which can b e as simple as a colour change, make them particularly suitable for highly sensitive field testing where the time and large equipment needed for more traditional testing is impractical. Their use is however limited to pollutants which can trigger biological antibodies - if the pollutants are too reactive, or say, immunosuppressive, they will either destroy the antibody or suppress its activity and so also the effectiveness of the test.

RESEARCH INTO EUROPEAN PUBLIC OPINION

Surveys(3,4) were carried out for the European Commission on opinions about the environment in the Member States in 1988 and 1992, and earlier in 1983(5) and 1987(6). The percentage of Europeans who believed that environmental protection is an "immediate an d urgent problem" increased from 74 to 85 percent from 1988 to 1992. This feeling of urgency grew in all countries, with the exception of Luxembourg. More than 9 out of 10 Europeans said they were "somewhat worried" or "very worried" about the threat posed by industrial waste, pollution of open waters, smog and damage to the environment in their own countries.

NEW BIOTECHNOLOGY: THE USE OF GMMOs

Recombinant DNA technology has had amazing repercussions in the last few years. Molecular biologists are mapping entire genomes, doctors are able to screen for genetic diseases and agriculturists are producing disease resistant plants. Ethical dilemmas and debates fill the air. But, for the time being, this most portentous development is unlikely to have much effect on environmental biotechnology. Although organisms "constructed" for specific applications exist in laboratories, it will be a while before these genetically modified microorganisms (GMMOs) are ready to work with their "ready-evolved" colleagues in the biodigester.

The advantage with GMMOs in biotechnology is that they can be designed to cope with wastes which no natural organism has evolved to metabolise. Occasionally a microbe may be found which has a biological pathway that happens to take in a biologically unusual substance (as in the methane degrading bacteria used in the earlier Savannah River example). Such chance pathways are generally inefficient for application in a bioreactor. It is theoretically possible to devise very much more effective GMMOs.

Problems do exist with specifically-designed organisms. Naturally occurring organisms have benefited from many millennia of evolution and as a result can often cope with a range of changing environmental conditions. In a competition for survival between a G MMO and a naturally occurring organism, GMMOs are rarely able to contend with changes in temperature, substrate or waste concentration and are so displaced. Engineering all these properties would be a formidable task. Yet, some fragility may be desirable if the GMMO is to be released into the environment, ensuring it has a restricted life-span.

Many applications of GMMOs could involve releasing them into the environment. This will happen in situations where ex situ remediation is impractical and no natural remediating organism exists. In any environmental situation, the micro-flora exists as a com plex, dynamic, interacting system. The release of GMMOs into the environment risks perturbing this system. This may still be the case where the aim of their introduction might be to restore an earlier pre-polluted state. While there is considerable resear ch being undertaken to assess such risks, the implications of any such disturbance are very difficult to predict. Most GMMOs are designed to deal with substances which do not occur naturally in the environment. Their existence should therefore be restricted to contaminated locations.

Europeans tend to have a positive attitude towards the use of GMMOs, according to the 1991 and 1993(5,6) European Commission public opinion surveys. Research into the use of GMMOs in environmental biotechnology is believed to be worthwhile and should be enc ouraged. Strong governmental control is, however, sought to ensure the safe use of GMMOs.

LEGISLATION

Regulation to ensure safe application of novel or modified organisms in the environment is important, not least to maintain public confidence. The European Union has two Directives(7,8) on the contained use of GMMOs, and on the deliberate release of GMMOs i nto the environment. These are now implemented in the national legislation of most EU Member States, with the remaining to follow. They require that a detailed experimental protocol, including assessment of potential risks, is approved by competent authorit ies before a GMMO is released into the environment. The nature and site of the release has also to be published in the local press.

After several years' experience using the legislation, the procedures involved are now being simplified. The aim is to maintain the EU's competitiveness globally - both in research and commercial applications, without compromising safety.

DIALOGUE AND DEBATE

Conferences, public debates, seminars and round table meetings have been held to bring people from the public, government, environmental organisations, science and industry together to discuss critical issues. These lively debates do not always lead to cons ensus, but they can provide a fuller appreciation of all the aspects in a particular issue; facilitating a better understanding of the problems involved.

Public information aimed at advancing dialogue and debate is provided by the European Union Directorate-General XI for Environment, Nuclear Safety and Civil Protection on environmental legislation(9) and biotechnology risk control(10). The Senior Advisory G roup Biotechnology of European companies (SAGB) has produced a publication about "Benefits and Priorities for the Environment"(11) and the OECD has recently published a report on "Biotechnology for a Clean Environment"(1). Environmental organisations, such as Natuur en Milieu in The Netherlands and BUND in Germany, also publish articles concerning biotechnology and the environment. The US Council for Responsible Genetics has several publications on issues in environmental biotechnology.

CONCLUSION

Environmental biotechnology has a career extending back into the last century. As the need is better appreciated to move towards less destructive patterns of economic activity, while maintaining improvement of social conditions in spite of increasing popula tion, the role of biotechnology grows as a tool for remediation and environmentally sensitive industry. Already, the technology has been proven in many areas and future developments promise to widen its scope. Some of the new techniques now under considerat ion make use of genetically modified organisms designed to deal efficiently with specific tasks. As with all situations where there is to be a release of new technology into the environmentconcerns exist. There is a potential for biotechnology to make a major contribution to protection and remediation of the environment. As we move into the next millennium this will become even more vitally important as populations, urbanisation and industrialisation continue to climb.

References

1 Biotechnology for a Clean Environment: Prevention, Detection, Remediation. OECD, Paris, 1994, ISBN 92 64 14257 6

2 Environmental Biotechnology, Edgington, S.M., Bio/technology, 13, 12, December 1994, pp 1338-42

3 Eurobarometer 29, "Europeans and their Environment in 1988", CEC, October 1988

4 Eurobarometer 37, "Europeans and the Environment in 1992", CEC, August 1992

5 Eurobarometer 35.1, "Opinions of Europeans on Biotechnology in 1991", in: Durant, J. (ed), "Biotechnology in Public", London: Science Museum, 1992. ISBN 0-901805-52-1

6 Eurobarometer 39.1, "Biotechnology and Genetic EngineeringWhat Europeans Think About It in 1993", Commission of the European Communities, October 1993

Genetically Modified Micro-organisms. 1990, 90/219/EEC

8 Council Directive on the Deliberate Release into the Environment of Genetically Modified Organisms. 1990, 90/220/EEC

9 Environmental Legislation. CEC DGXI, 1994

10 Biotechnology Risk Control. CEC DGXI, 1994, ISBN 92 826 7029 5

11 Benefits and Priorities for the Environment, Senior Advisory Group Biotechnology (SAGB), Brussels, 1994

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© Copyright EFB Task Group on Public Perceptions of Biotechnology, 1996.

The Task Group gratefully acknowledges the continuing support and funding of the European Commission for this and other briefing papers.

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