ABSTRACT
A molecularbiological approach was used to analyse the bacterial populations in surface- and groundwater. The bacterial DNA was isolated and purified by adapting and modifying standard protocols with attention to the special characteristics of the analysed samples. PCR (Polymerase chain reaction) with universal primers was used to amplify a variable region of the 16S rRNA gene. Based on their sequence differences similar sized PCR products were separated by DGGE (Denaturing gradient gel electrophoresis). DGGE-patterns from ground- and surface water as well as lake sediment were compared with regard to common features and differences in species composition. Samples from groundwater with different hydrogeochemical conditions revealed great differences in DGGE-patterns indicating a characteristic species composition in these habitats. Related samples showed less or no differences in DGGE patterns. Temporal variation in species composition was demonstrated in surface water over a period of 6 month.
