Szukana fraza: [Abstract = This work presents the results of microbiological investigations carried out in the Polish part of the Muskau Arch. In this abandoned lignite mining area highly acidified Fe\-rich waters have been formed as a result of sulphide oxidation. Microbiological tests have shown that all studied groups of microorganisms exhibit both time and spatial variability. The most common group of microorganisms are bacteria Galionella sp.]