Mycrocystin-LR degradation by indigenous bacterial community of Rybinsk Reservoir

Abstract

The fate of microcystin-LR (MC-LR) in water samples of Rybinsk Reservoir taken before and during water bloom was assessed. The decrease in the MC-LR concentration in the both samples was due to its biodegradation by indigenous bacterial community. The highest biodegradation rate and shortest half-life of MC-LR in the water sample taken during water bloom were observed. A microcystin degrading bacterium was isolated and shown be 98.92% similar to Sphingopyxis sp. based on a fragment of 16S rRNA gene sequence. The rate of MC-LR biodegradation by Sphingopyxis sp. S7 was strongly dependent on initial concentration of toxin and temperature.