Microcystins in Cyanobacterial Biofilms from the Littoral Zone of Lake Baikal

• Published in: Moscow University biological sciences bulletin Vol. 72; no. 4; pp. 225 - 231
• Main Authors: Belykh, O. I., Fedorova, G. A., Kuzmin, A. V., Tikhonova, I. V., Timoshkin, O. A., Sorokovikova, E. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-10-2017; Springer Nature B.V
• Subjects: Benthos; Biochemistry; Biofilms; Biofouling; Biomedical and Life Sciences; Cell Biology; Cyanobacteria; Ecology; Enzyme-linked immunosorbent assay; Life Sciences; Littoral zone; Microcystins; Plankton; Plant Sciences; Zoology; MALDI-TOF/TOF; microcystins; sponges; Lake Baikal; cyanobacteria; ELISA
• ISSN: 0096-3925; 1934-791X
• DOI: 10.3103/S0096392517040022

Some species of cyanobacteria synthesize toxins whose concentration during water bloom can reach values dangerous for human and animal health. Planktonic cyanobacteria are the most common and well-studied microcystins producers, hepatotoxic cyclic heptapeptides, whereas microcystin-producing benthic cyanobacteria are less known. In recent years, the mass development of benthic cyanobacteria forming extensive fouling on different substrates has been detected in the littoral zone of Lake Baikal. We found microcystins produced by benthic cyanobacteria in the biofouling on different natural and artificial substrates, including diseased and dead endemic sponges
Lubomirskia baicalensis
and
Baikalospongia
spp. collected from the littoral area of Lake Baikal. Microscopic analysis of the biofouling revealed prevalence of representatives of
Nostocales
and
Oscillatoriales
with predominance of
Tolypothrix distorta
that is likely the main microcystin producer in Lake Baikal. According to enzyme-linked immunosorbent assay (ELISA), microcystin concentrations in biofouling were 29.8–3050 μg/kg dry weight. We identified eight microcystin variants using MALDI-TOF/TOF; [Dha7]MC-YR was detected in most samples. The presence of microcystins in biofilms formed on the surface of the artificial substrate by
Phormidium autumnale
was also recorded. The data obtained demonstrated the necessity to monitor potentially toxic species and concentrations of cyanotoxins in plankton and benthos in the littoral zone of Lake Baikal, especially in the regions with intense tourist and recreational activities.