Report of the Biotechnology Science Advisory Committee of the U.S. Environmental Protection Agency / the Committee.

  • United States. Environmental Protection Agency. Biotechnology Science Advisory Committee.
Date:
1987
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Licence: Public Domain Mark

Credit: Report of the Biotechnology Science Advisory Committee of the U.S. Environmental Protection Agency / the Committee. Source: Wellcome Collection.

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    Biotechnology Science Advisory Committee; Subcommittee on Definition of Pathogen February 26-27, 1987 Introduction Although biotechnology is thousands of years old, several concerns have been raised over the past 15 years by the use of the techniques (recombinant DNA, cell fusion, etc.) which have been called the ‘‘new’’ biotechnology. Be- cause these ‘‘new’’ techniques permit precise manipula- tion of the genetic inheritance of organisms and cir- cumvention of species barriers, these techniques are very powerful. One of the concerns associated with the use of the techniques known as the ‘‘new”’ biotechnology is that ‘‘hazardous’’ microorganisms might be produced through these techniques. Although at this time this con- cern is conjectural, it has been hypothesized that such an outcome may be more likely in some circumstances than in others, and such circumstances have generally been subjected to greater scrutiny. One circumstance where it is hypothesized such an outcome may be more likely is when the parent organisms (i.e., organisms used as hosts or donors in constructing microorganisms to perform specific tasks) are pathogens, since pathogens have the intrinsic potential to cause adverse effects. Pathogens are microorganisms that cause disease in other organisms (human, animal, plant or other micro- organisms), with ‘‘disease’’ being defined as an abnor- mal physiological process in an organism. These abnor- mal physiological processes encompass a broad range of effects such as oncogenicity, teratogenicity, mutagenici- ty, altered immune responses, and interruptions in cellular metabolism. There are several mechanisms whereby microorganisms can induce such adverse effects One such mechanism is when the proliferating micro- organisms grow in or on the target organism’s tissues and directly affect the target organism. For example, some pathogenic organisms produce toxins, other pathogenic microorganisms produce enzymes that degrade tissue. Microorganisms can also cause deleterious effects when they grow outside of the target organism but pro- duce organic toxins which can work ‘‘from a distance.’’ An example of this mechanism is a disease of chrysan- themums called strap leaf. This disease is caused by a tox- in produced by Aspergillus growing in the soil. Another way microorganisms can harm other organ- isms is by altering the habitat and thereby indirectly af- fecting other populations also occupying that habitat. One example of this phenomenon arises when there are population imbalances within the microbial communi- ty. For example, large influxes of nutrients can lead to large algal blooms in lakes. These algal blooms produce anoxic conditions which can lead to disease symptoms and death in oxygen-requiring populations such as fish. Report of the Biotechnology Science Advisory Committee In this case, the adverse effects are due to anoxia caused may also be produced by microbial populations which produce inorganic chemicals that can cause abnormal physiological processes in other organisms. For example, hydrogen sulfide produced by microbial populations in sediment can accumulate to concentrations toxic to other organisms. It has been suggested that another circumstance which might deserve regulatory scrutiny is applications involv- ing microorganisms controlling important biogeochem- ical cycles, such as nutrient cycling.* Changes in biogeo- chemical processes are of concern because these impor- tant processes greatly influence the homeostasis of the planet and, it has been hypothesized, adverse effects could ensue if the balances between microorganisms playing a major role in these processes are disrupted. An example of an important element cycle is the nitrogen cycle. Nitrogen plays an essential role in living organisms and is a key element limiting growth. Although nitrogen is an abundant atmospheric gas, this form is not directly usable by the majority of organisms. Only certain species of bacteria and blue-green algae possess the ability to reduce and fix atmospheric nitrogen. The importance of these organisms in maintaining a balance between fixed and atmospheric nitrogen is seen in the following. In oceanic or terrestrial ecosystems, where nitrogen is the major limiting nutrient, gaseous loss of nitrogen, if it is not compensated by organisms capable of fixing nitrogen, would reduce the nitrogen available for living organisms. On the other hand, an increase of 1% in the emission rate of N.O would cause a 0.2% decrease in stratopheric ozone, increasing the transmissivity of ultraviolet light through the atmosphere. As part of its effort to address concerns about ‘‘poten- tially hazardous’’ microorganisms, the Environmental Protection Agency (EPA) has convened a group of experts to discuss which groups of microorganisms should, because these organisms might possess an intrinsic poten- tial to cause adverse effects, be subjected to a greater regulatory scrutiny. History A brief review of the history of recombinant DNA, one of the techniques of the ‘‘new’’ biotechnology, is included in this report to show how the concept of ‘‘pathogen’’ has influenced the oversight of recombinant DNA technol- ogy. It was the scientists who engaged in research using the technique termed recombinant DNA who first called for assessment of the risks which might be associated with this technique, and for guidelines which would permit research to proceed in a cautious manner. The National Institutes of Health (NIH) was asked to develop these guidelines. In July 1976, NIH published its Guidelines for Research Involving Recombinant DNA Molecules.’ In this original version of the guidelines, certain experiments were ‘‘not to be initiated. . . ”’ Included in this group *Nutrient cycling refers to the fluxes of elements and other nutrients in the ecosystem. Zs
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