Abstract
(English)
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Currently available as well as newly isolated organisms degrading or transforming organohalogen pollutants, under aerobic or anaerobic conditions, will serve as the starting point to isolate the metabolic diversity of degrading genes present from contaminated and pristine environments using a molecular primer approach. A periodically upgraded database linking given structures with metabolic potential will support the creation of molecular tools which, after development of optimised protocols, will enable the quantification of metabolically-active organisms, of degrading genes, of the expression of those genes and, therefore, enhance the bioremediation potential of organohalogen-contaminated sites. New products and services in environmental biotechnology will become available.
Scientific objectives and approach:
Molecular detection methods will developed and optimised for the monitoring of bioremediation processes. A combination of detection of specific microorganisms, detection of catabolic genes and transformation activity, all in situ, will allow the accurate analysis of in situ natural attenuation. Results of the characterisation of intrinsic potentials of organohalogen-polluted sites by classical microcosm studies will be used to assess the usefulness of the molecular tools developed during the time-course of the project.
A knowledge base created by the detailed genetic and biochemical characterisation of a collection of DNA segments encoding catabolic genes, will be used for the development of probes and primers for extracting the broadest possible diversity of genes from the environment. A database relating genetic structure to metabolic function for various key enzymes of halogenated hydrocarbon degradation will be built up and after optimisation of protocols for isolating DNA and RNA from environmental samples, as well as the adaptation of quantitative PCR methods, used for the development of specific probes and primers to analyse and quantify the presence and expression of degradative pathways in contaminated samples, to characterise enrichment cultures and to monitor the evolution of dechlorinating activity in microcosms. Results of this validation phase will be used to optimise the molecular tools already available. Finally, newly developed and optimised methods will be converted to an economic method to identify and quantify by molecular methods the natural attenuation potential of contaminated sites.
Problems to be solved:
Chlorinated hydrocarbons are the most important and widespread class of contaminants of soil and groundwater in all European countries and environmentally friendly methods have to be developed to abate this pollution. Many examples of bacterial transformation and, even, mineralisation of these compounds have been found. In field situations, stimulated or natural (intrinsic) bioremediation may, therefore, be a suitable remediation strategy for reducing risks. However, in practice, it is difficult to predict the bioremediation potential of the indigenous microbial population at polluted sites. Hence, there is a need for the development of effective, easy to handle tools for predicting degradative potential or for monitoring the effective stimulation of catabolic pathways in situ. These tools should not be dependent on the culturability of contaminant-degrading organisms but, rather, be directed at the detection of the genes specific for microorganisms and genes encoding enzymes that catalyse the key reactions in the degradation pathways of contaminants.
Expected Impacts:
The project will directly contribute to a better pollution and waste management and reduce exposure to harmful pollutants by increasing our understanding of the biochemical factors that are critical in degradation of halogenated pollutants in the environment and thereby allowing the rational manipulation of biological or other parameters at a polluted site.
The application of rapid molecular culture-independent detection methods for biomonitoring purposes will allow accurate analyses of in situ natural attenuation and stimulated in situ biorestauration, leading to decreased costs of biotechnological remediation. Therefore, the results of this project will increase the market for suppliers of biotechnological waste-treatments and consultancy in environmental biotechnology.
The proposed efforts will not only help in facilitating biological remediation and stimulate the use of those techniques in Europe. We anticipate that the project will also lead to automate high-throughput methods that allow a routine use and will become available to SMEs working on bioremediation and thereby will lead to the development of a technology for industrial use, will foster the use of environmentally friendly biological remediation techniques and generally support the use of new molecular methods to monitor biological processes.
The stimulation of bioremediation techniques furthermore directly contributes to preserve and enhance the environment.
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