Methods to study environmental occurrence, fate and chemico-biological interactions
                                     of cyanobacterial toxins

                                            Libor Jaša

                               Supervisor: RNDr. Pavel Babica, Ph.D.


Cyanobacteria (blue-green algae) are photosynthetic prokaryotic organisms with the ability to
synthesize chlorophyll-a and produce a wide range of secondary metabolites, including
cyanobacterial toxins (cyanotoxins). Most widespread bloom-forming cyanobacteria genus is
Microcystis, the main producer of the hepatotoxic peptide microcystin ^1. It has been estimated
that 25-75% cyanobacterial blooms are toxic. Cyanotoxins represent an important group of chemical
compounds which are intensively studied with respect to their chemical properties and the presence
in the environment, and with regard to their toxicity and ecotoxicity ^2. The toxic cyanobacteria
can induce a range of adverse effects, from headaches, dizziness, nausea, diarrhea, skin irritation
to the neurotoxic effects or acute/chronic damage to the liver or other organs ^3.

Microcystins (MCs) are recognized as the most hazardous cyanotoxins with respect to their potential
for both acute and chronic effects on wildlife or human health. These substances cause primarily
hepatotoxic or hepato-carcinogenic effects in mammals; and World Health Organization (WHO)
recommended a guideline value of 1 µg/L for MC-LR in drinking water^4.

The presentation will primarily focus on sampling and monitoring cyanotoxins in water reservoirs,
which serve as a source for drinking water treatments plants (DWTPs), and for evaluation of toxin
removal efficiency during the treatment process. POCIS type passive sampler was optimized,
evaluated and calibrated and used for monitoring of MCs and comparison with conventional grab
sampling. Next studies focused on the development of passive sampler for emerging cyanotoxin
cylindrospermopsin, microcystin oxidation with high-valent iron oxidant, determination MCs in
invasive bryozooan Pectinatella magnifica, isolation and purification of secondary metabolites
(microginin and anabaenopeptin) from cyanobacterial water bloom biomass.

1.             Fastner J, Erhard M, von Dohren H. Determination of oligopeptide diversity within a
natural population of Microcystis spp. (Cyanobacteria) by typing single colonies by matrix-assisted
laser desorption ionization-time of flight mass spectrometry. Applied and Environmental
Microbiology. 2001;67(11):5069-5076.

2.             Blaha L, Babica P, Marsalek B. Toxins produced in cyanobacterial water blooms -
toxicity and risks. Interdisciplinary toxicology. 2009;2(2):36-41.

3.             Dittmann E, Fewer DP, Neilan BA. Cyanobacterial toxins: biosynthetic routes and
evolutionary roots. Fems Microbiology Reviews. 2013;37(1):23-43.

4.             Svircev Z, Drobac D, Tokodi N, Mijovic B, Codd GA, Meriluoto J. Toxicology of
microcystins with reference to cases of human intoxications and epidemiological investigations of
exposures to cyanobacteria and cyanotoxins. Archives of Toxicology. 2017;91(2):621-650.