The modern methods development for microbiological water quality assessment in lakes

Abstract

The functional diversity of free-living aquatic protozoans is discussed with respect to the feeding ecology, life strategies and water quality. Heterotrophic nanoflagellates (HNF) are known as most important grazers of bacteria in many aquatic ecosystems. Recent studies of flagellate feeding processes indicated that there are significant species-specific variability regarding the food uptake and food selection of bacterivorous flagellates. The Choanoflagellida have an essential role in microbial food webs contributing to a process of self-purification of water bodies as well as are used in monitoring systems. We show that diversity and relative abundance of ciliates and other protozoans can be used as indicators of toxic pollution and acidification. Multivariate statistics were used to design “the scale of toxicity” across a gradient of toxicant stress and organic compounds. A new index of periphyton flagellates (IPF) as indicator of the trophic status of a water-body and a simplified index for a sublethal toxicity assessment were developed.