Features of cyanobacterial-algal communities in artificial ecosystems of treatment facilities of Meleuz City

In this article, cyanoprokaryotes and algae of activated sludge of biological treatment facilities of the city of Meleuz were studied. The research revealed 27 species of algae and cyanoprokaryotes from 4 divisions. The leading class in terms of the number of species is Cyanophyceae: they accounted for 14 species, or 35.5% of the total number of species. In second place belongs to representatives of the class Bacillariophyceae (19.3%), followed by representatives of the class Chlorophyceae (12.9%). Four classes (Trebouxiophyceae, Mediophyceae, Coscinodiscophyceae, Euglenophyceae) were represented by single species. Most taxa below the class (orders, families, genera) are also represented by single species. The structure-forming species (the most common) include 3 species of cyanoprokaryotes: Microcystis aeruginosa, Oscillatoria planctonica, Arthrospira platensis. The number of saprobity indicator species (degree of organic pollution) was 18 species, or 58% of the total number of species. Indicators of all saprobic zones, except for xenosaprobic ones, were revealed. The degree of organic pollution was 2.96, which corresponds to the mesosaprobic zone. There is no correlation between the number of species and seasonality, and the communities are relatively stable. It can be concluded that the cyanoprokaryotic-algal communities of activated sludge of biological treatment facilities in the city of Meleuz are characterized by a poor species composition, with a predominance of zionoprokaryotes. The level of organic pollution corresponds to a moderately polluted area.