Study on the ecology of selected micro-organisms

Abstract

The report consists of a general part (A) and a specific part (B). Part (A) of this literature study gives an overview of the ecological significance of micro-organisms in general. A further focus is the discussion of existing approaches for the assessment and evaluation of ecological risks which may occur following the release of bacteria with certain characteristics, e.g. genetically engineered micro-organisms (GEMs). As a possible alternative to the qualitative risk characterization, a quantitative evaluation strategy that is analogous in orientation to the PEC/PNEC approach for chemicals or presticides was elaborated. The main aspect of this approach is that the fate of micro-organisms or genes as well as their effect on ecosystem structures and functions are quantified separately for different environmental compartments. The risk to the environment is then assessed on the basis of compartment-specific dose-effect relationships. Special emphasis was also placed on the possibilities for standardizable experimental determination of microbial effects on the environment. For this reason, the existing guidelines for the ecotoxicological testing of chemicals and pesticides as well as microbial pesticides were evaluated with respect to their applicability for testing of GEMs. Part (B) of the literature study is a compendium of the data available on the ecology of six bacteria species whose release in the context of agricultural or biotechnical application has already occurred or is pending: Pseudomonas fluorescens, Pseudomonas putida, Bacillus subtilis, Bacillus thuringiensis, Rhizobium leguminosarum and Sinorhizobium meliloti. The information concerning the ecology of these organisms applies to specific habitats as well as the dispersal of the bacteria, their influence on the nutrient balance in nature and their role within the biotic system. (orig.)Summary in GermanSIGLEAvailable from TIB Hannover: RN 8422(1998,65) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman