Field Testing Genetically Modified Organisms Framework for Decisions (1989) / Chapter Skim
Currently Skimming:
7 Past Experience with the Introduction of Microorganisms into the Environment
7 Past Experience with the Introduction of Microorganisms into the Environment
Pages 77-85
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 77... ...
This history of safe use and an understanding of genetic modification through modern methods combine to give scientists a degree of familiarity with certain rn~croorgan~sms. This chapter wiD describe the familiarity we have with certain croorganisms as background for use of a familiarity criterion in a framework to help in evaluating the relative safety or risk of field testing geneticaDy modified rn~croorganisms.
|
From page 78... ...
Agriculture The history of introduction of naturally occurring microorganisms into the environment for agricultural purposes provides extensive data on the release of genetically modified microorganisms. The microorganisms that have attracted the greatest attention for agricultural applications include: (1)
|
From page 79... ...
thuringiensts by introducing the delta endotoxin gene into the chromosome of Pseudfomonas puorescens, an effective colonizer of corn plants (Obukowicz et al., 1987~. The organism has not been field-tested but laboratory studies indicate that this genetically modified bacterial strain does not differ from its parental strain in survival and dispersal characteristics, and it Is somewhat toxic to root cutworm but not to the corn rootworm.
|
From page 80... ...
inoculants over many years provides a good example of the safe use of genetically modified m~croorganisrns. Improvements in biological nitrogen fixation will be important for meeting future demands of agriculture, reducing requirements for fertilizer, conserving fossil fuels used in producing and applying nitrogenous fertilizer, as well as in mmirn~z~g adverse environmental effects from run-off of nitrogenous fertilizers into lakes and streams.
|
From page 81... ...
The attractiveness of bioremediation treatment is that in both surface and subsurface environments microbial processes may permanently remove organic contaminants, rather than merely contain them. Tm addition, bioremediation by introduced microorganisms may continue ~ situ even after ~ntroauctions have ceased.
|
From page 82... ...
in activated sludge; mollified microorganisms survived and functioned with no adverse effects on the rest of the microbial community and with no trance fer of the new genetic information to indigenous microorganisms. Genetic modifications also may provide significant unproYements in the rates of degradation and the range of toxic pollutants subject to degradation.
|
From page 83... ...
SIMILARITIES AND DIFFERENCES BETWEEN CLASSICAL AND MOLECULAR METHODS The preceding section illustrates a long history of beneficial applications of microorganisms in food processing, agriculture, waste treatment, and bioremediation. In many instances, such applications can be performed even more effectively with rn~croorganisms that have been genetically modified, by either classical methods or molecular techniques (NAS, 1977; OTA, 1984, 1988; GiDett et al., 1985; Korwek and de la Cruz, 1985; Olson, 1986; Timmis et al., 19883.
|
From page 84... ...
Unfamiliar microorganisms or instances of substantial uncertainty about the interaction of the microorganism and the environment into which it is to be introduced require careful evaluation prior to field testing. Issues pertaining to the biology of a field test that have ecological significance include the following: the functional role or niche of the rn~croorganism In the microbial community and ecosystem, the potential for gene exchange between microbial taxa, the ability to monitor persistence and spread of microorganisms, the potential ecological consequences of the persistence and spread of such m~croorganisrns, and the potential measures to control, if necessary, the effects of introduced microorganisms.
|
From page 85... ...
Comparable modifications can often be accomplished with either method, and each type follows procedures to selectively enrich those genotypes that have the desired phenotypic properties. Molecular methods often provide greater precision in generating the desired genotype and greater power in producing novel genetic combinations.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.