The ecotoxicity assessment of new substances is crucial for their considered launch on the market. Due to various properties of chemical compounds, however, the application of biotests can be challenging. In the case of insoluble compounds, a proper, non-toxic solvent must be applied. The presented preliminary results demonstrate the extremely high ecotoxicity of camphor and camphor oxime, assessed by means of the Microtox system. A 81.9% Basic Test with 14 dilutions was applied. The ecotoxicity of a solvent (i.e. DMSO) was also assessed. The initial concentration of substances was 5%. EC50 values reached 0.00023% and 0.00007% for camphor and camphor oxime, respectively, after 15 min. of incubation of the samples with bioluminescent bacteria. The ecotoxicity of the solvent remained negligible. Due to the extremely high ecotoxicity values of the tested substances, another range of concentrations needs to be applied in future tests to confirm the results.

Abstract. Numerous microorganisms may be present in the water distribution system. This is associated with the imperfection of purification processes, or secondary water pollution. Not only it results in the deterioration of water quality parameters, but it also increases threat of epidemiological problems. The water that is biologically unstable creates ideal conditions for colonization of the microorganisms to the inner surface of pipelines which may form biofilm. The key issue, enabling prevention and control of the impact of the development of biofilms, is to assess the biodiversity of microbiocenosis. In order to obtain comprehensive characteristics of microorganisms communities on a particular substrate, it is necessary to combine several techniques. Further analysis using molecular biology methods are usually after traditional methods of assessing the microbiological quality of water. Standard methods do not reflect the actual species composition, because they are targeted at the bacteria that can be isolated and cultured in the laboratory. Conventional methods are capable of detecting less than 10% of the organisms in the sample. In order to study the biodiversity of organisms inhabiting a biofilm (apart from the conventional methods) analyses of the diversity of nucleic acids should be used. The first method could be the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Another way may be fluorescence in situ hybridization, which allows to detect determined DNA sequence using specially labeled oligonucleotide probes. Visualization of the material is performed using a fluorescence microscope. The main purpose of this article is to present rapid and precise identification groups of microorganisms in their natural habitat in biofilm using fluorescent in situ hybridization method (FISH) . FISH method can be successfully used to visualize these microorganisms, which show difficulties in culturing, as well as to provide knowledge on the phylogenetic structure in different habitats. FISH technique allows the quantitative description of environmental samples.

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Abstract. The lack of biological stability of water which is introduced into the network, leads primarily to its secondary contamination during transport to the consumer. The water that is biologically unstable creates ideal conditions for colonization of the inner surface of pipelines by microorganisms and adhesion of their products (biocorrosion). The studies was conducted using the identified microorganisms isolated from the water supply network which accounted inocula in continuous culture of biofilm in CDC reactor. As a result of studies it was revealed the presence of biofilm formed on different materials polyethylene, polypropylene, polyvinyl chloride, polybutylene. Microbiological biodiversity of organisms inhabiting a biofilm of the diversity of nucleic acids was used. It was observed the amount of the psychrophilic bacteria oscillation in the effluent from the reactor. It was also determined the affinity of various bacteria to the plastic through adhesion measurement using impedance spectroscopy. For impedance measurements apparatus SIGNAL RECOVERY 7280 DSP LOCK-IN AMPLIFIER was used, recording impedance components (real and imaginary). The results will allow for the creation of biosensor systems that can be used in predicting health risks in connection with drinking water and taking corrective actions.