Field Calibration of Soil-core Microcosms for Evaluating Fate and Effects of Genetically Engineered Microorganisms in Terrestrial Ecosystems

Field Calibration of Soil-core Microcosms for Evaluating Fate and Effects of Genetically Engineered Microorganisms in Terrestrial Ecosystems PDF Author:
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Category :
Languages : en
Pages :

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Pacific Northwest Laboratory compared intact soil-core microcosms and the field for ecosystem structural and functional properties after the introduction of a model genetically engineered microorganism (GEM). This project used two distinct microbial types as model GEMs, Gram-negative Pseudomonas sp. RC1, which was an aggressive root colonizer, and Gram-positive Streptomyces lividans TK24. The model GEMs were added to surface soil in separate studies, with RC1 studied throughout the growth of winter wheat (Triticum aestivum), while TK24 was studied throughout a ten month period. Also, RC1 was used in studies conducted during two consecutive field seasons (1988 to 1990) to determine how year-to-year field variability influenced the calibration of microcosms with the field. The main conclusions of this research were that intact soil-core microcosms can be useful to simulate the field for studies of microbial fate and effects on ecosystem structural and functional properties. In general, microcosms in the growth chamber, which simulated average field variations, were similar to the field for most parameters or differences could be attributed to the great extremes in temperature that occurred in the field compared to the microcosms. Better controls of environmental variables including temperature and moisture will be necessary to more closely simulate the field for future use of microcosms for risk assessment. 126 refs., 13 figs., 12 tabs.

Field Calibration of Soil-core Microcosms for Evaluating Fate and Effects of Genetically Engineered Microorganisms in Terrestrial Ecosystems

Field Calibration of Soil-core Microcosms for Evaluating Fate and Effects of Genetically Engineered Microorganisms in Terrestrial Ecosystems PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Pacific Northwest Laboratory compared intact soil-core microcosms and the field for ecosystem structural and functional properties after the introduction of a model genetically engineered microorganism (GEM). This project used two distinct microbial types as model GEMs, Gram-negative Pseudomonas sp. RC1, which was an aggressive root colonizer, and Gram-positive Streptomyces lividans TK24. The model GEMs were added to surface soil in separate studies, with RC1 studied throughout the growth of winter wheat (Triticum aestivum), while TK24 was studied throughout a ten month period. Also, RC1 was used in studies conducted during two consecutive field seasons (1988 to 1990) to determine how year-to-year field variability influenced the calibration of microcosms with the field. The main conclusions of this research were that intact soil-core microcosms can be useful to simulate the field for studies of microbial fate and effects on ecosystem structural and functional properties. In general, microcosms in the growth chamber, which simulated average field variations, were similar to the field for most parameters or differences could be attributed to the great extremes in temperature that occurred in the field compared to the microcosms. Better controls of environmental variables including temperature and moisture will be necessary to more closely simulate the field for future use of microcosms for risk assessment. 126 refs., 13 figs., 12 tabs.

Evaluation of Terrestrial Microcosms for Assessing the Fate and Effects of Genetically Engineered Microorganisms on Ecological Processes

Evaluation of Terrestrial Microcosms for Assessing the Fate and Effects of Genetically Engineered Microorganisms on Ecological Processes PDF Author:
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Category :
Languages : en
Pages :

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This project evaluates and modifies the existing US Environmental Protection Agency's Office of Pesticides and Toxic Substances (EPA/OPTS) terrestrial microcosm test system and test protocols such that they can be used to determine the environmental fate and ecological hazards of genetically engineered microorganisms (GEMs). The intact soil-core microcosm represents terrestrial ecosystems, and when coupled with appropriate test protocols, such microcosms may be appropriate to define and limit risks associated with the intentional release of GEMs. The terrestrial microcosm test system was used to investigate the survival and transport of two model GEMs (Azospirillum lipoferum and Pseudomonas sp. Tn5 mutants) to various trophic levels and niches and through intact soil cores. Subsequent effects on nutrient cycling and displacement of indigenous microorganisms were evaluated. The model organisms were a diazotrophic root-colonizing bacterium (A. lipoferum) and a wheat root growth-inhibiting rhizobacterium (Pseudomonas sp.). The transposable element Tn5 was used as a genetic marker for both microorganisms in two separate experiments. The organisms were subjected to transposon mutagenesis using a broad host-range-mobilizable suicide plasmid. The transposon Tn5 conferred levels of kanamycin resistance up to 500 .mu.g/ml (Pseudomonas sp.), which allowed for selection of the bacteria from environmental samples. The presence of Tn5 DNA in the genome of the model GEMs also allowed the use of Tn5 gene probes to confirm and enumerate the microorganisms in different samples from the microcosms. Two types of root growth-inhibiting Pseudomonas sp. Tn5 mutants were obtained and used in microcosm studies: those that lacked the ability to inhibit either wheat root growth or the growth of other microorganisms in vitro (tox/sup /minus//) and those which retained these properties (tox/sup +/). 53 refs., 7 figs., 6 tabs.

Biotechnology, Research Program Overview

Biotechnology, Research Program Overview PDF Author:
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ISBN:
Category : Bioremediation
Languages : en
Pages : 20

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
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Category : Aeronautics
Languages : en
Pages : 602

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Molecular Microbial Ecology Manual

Molecular Microbial Ecology Manual PDF Author: A.D. Akkermans
Publisher: Springer Science & Business Media
ISBN: 9401103518
Category : Science
Languages : en
Pages : 491

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Book Description
For a long time microbial ecology has been developed as a distinct field with in Ecology. In spite of the important role of microorganisms in the environ ment, this group of 'invisible' organisms remained unaccessable to other ecologists. Detection and identification of microorganisms remain largely dependent on isolation techniques and characterisation of pure cultures. We now realise that only a minor fraction of the microbial community can be cultivated. As a result of the introduction of molecular methods, microbes can now be detected and identified at the DNA/RNA level in their natural environment. This has opened a new field in ecology: Molecular Microbial Ecology. In the present manual we aim to introduce the microbial ecologist to a selected number of current molecular techniques that are relevant in micro bial ecology. The first edition of the manual contains 33 chapters and an equal number of additional chapters will be added this year. Since the field of molecular ecology is in a continuous progress, we aim to update and extend the Manual regularly and will invite anyone to deposit their new protocols in full detail in the next edition of this Manual.

Government Reports Annual Index

Government Reports Annual Index PDF Author:
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ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1128

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Handbook of Environmental Risk Assessment and Management

Handbook of Environmental Risk Assessment and Management PDF Author: Peter P. Calow
Publisher: John Wiley & Sons
ISBN: 1444313193
Category : Technology & Engineering
Languages : en
Pages : 600

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Book Description
At the heart of environmental protection is risk assessment: thelikelihood of pollution from accidents; the likelihood of problemsfrom normal and abnormal operation of industrial processes; thelikely impacts associated with new synthetic chemicals; and so on.Currently, risk assessment has been very much in the news--therisks from BSE and E. coli, and the public perception of risks fromnuclear waste, etc. This new publication explains how scientificmethodologies are used to assess risk from human activities and theresultant objects and wastes, on people and the environment.Understanding such risks supplies crucial information--to framelegislation, manage major habitats, businesses and industries, andcreate development programmes. Unique in combining the science of risk assessment with thedevelopment of management strategies. Covers science and social science (politics, economics,psychology) aspects. Very timely - risk assessment lies at the heart of decisionmaking in various topical environmental questions (BSE, Brent Spar,nuclear waste).

AKKERMANS MOLECULAR MICRO ECOL,

AKKERMANS MOLECULAR MICRO ECOL, PDF Author: A. D. L. Akkermans
Publisher: Springer
ISBN:
Category : Juvenile Nonfiction
Languages : en
Pages : 534

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This text offers general information about molecular techniques relevant to molecular ecological research. Attention is paid to the use of molecular methods for studying the fate of genetically modified and native microorganisms in the environment.

EPA Publications Bibliography

EPA Publications Bibliography PDF Author:
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Category : Environmental protection
Languages : en
Pages : 1030

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Energy Research Abstracts

Energy Research Abstracts PDF Author:
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Category : Power resources
Languages : en
Pages : 678

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