Identification of toxin-producing cyanobacteria in water reservoirs of Kirov region and assessment of their relationship with water toxicity to hydrobionts

Abstract

Molecular genetic methods of analysis were used for the first time detection of cyanotoxin biosynthesis genes (microcystin, cylindrospermopsin, anatoxin-a, and saxitoxins) in organisms inhabiting the two largest water reservoirs of Kirov region (Belokholunitsky and Omutninsky) located in the northeast of the Russian Plain in the southern taiga subzone. The mcyE gene responsible for microcystin production was detected in all phytoplankton samples, and the anaC gene responsible for anatoxin-a production was detected in the most samples. 14 cyanobacteria taxa were found in the phytoplankton of the studied reservoirs. Microcystis and Dolichospermum are the most probable microcystin producers. The most probable anatoxin-a producers in Belokholunitsky reservoir are Aphanizomenon flos-aquae and Dolichospermum planctonicum, and in Omutninsky reservoir – Cuspidothrix issatschenkoi and Dolichospermum flos-aquae. Water from the studied reservoirs had an acute toxic effect on luminescent bacteria Escherichia coli (“Ecolum” test system) and protozoa Paramecium caudatum Ehrenberg, but was non-toxic to Entomostracans Daphnia magna Straus.