The applications of microbes in environmental monitoring

Harmful effects of contaminants on the ecosystem and humans can not be assessed by standard chemical analyses of environmental samples, therefore toxicity tests using live organisms or cells represent a vital part of environmental monitoring. Many different biological methods based on native or genetically modified microorganisms as test-species, have already successfully been applied to environmental toxicity/genotoxicity assessment. An important reason is the modern 3R concept (reduction, replacement, refinement) in toxicology and ecotoxicology, which promotes the application of microorganisms in biotests due to simple cultivation in axenic cultures and due to the lack of ethical problems. The article reviews the most important applications of bacteria, protozoa, algae and yeasts in biomonitoring, starting with classical physiology-based toxicity bioassays, proceeding to genotoxicity assays, immunoassays and endocrine disruptor assays and concluding with upcoming approaches of toxicogenomics.