Introduction: Microalgae are a diverse group of autotrophic organisms that have the ability to grow rapidly. In a global scale approximately 80 species are proven to have the capacity to produce potent toxins (phycotoxins) which tend to accumulate in other organisms in the food chain and could affect the human health. The negative function of yessotoxin (YTX) on the human health is debatable but it is supposed to be a helpful drug for pharmacological approaches. A total number of 28 potentially toxin species have been observed along the Bulgarian Black Sea coast. Among them are Protoceratium reticulatum, Gonyaulax spinifera and Lingulodium polyedrum which are known to produce YTX. The aims of this study are to reveal that Black Sea phytoplankton has the potential to be a source of YTX, to suggest conditions that increase this potential and to review the pharmaceutical purposes YTX can be used for.
Materials and methods: Plankton sampling is conducted in autumn 2016 and spring 2017 on the Bulgarian Black Sea coast. YTX determination is performed with liquid chromatography coupled with mass spectrometry.
Results: 20 plankton samples were analysed whereas 12 were positive for YTX. YTX concentration varies 20-20000 pg/NH/m. Parameters as salinity of about 32 ‰, average water temperature of about 15,5 °C, phosphate concentration of around 0,46 μM and very low nitrogen concentration are reported to enhance the toxic phytoplankton proliferation and YTX production both in laboratory and natural conditions. YTX is proposed as a lead molecule to treat and/or prevent metabolic diseases, for therapy of Alzheimer`s disease, allergy processes etc.
Conclusions: Phytoplankton from the Bulgarian Black Sea coast produces YTX. Isolation and culturing of Black Sea species by appropriate conditions could facilitate YTX production. This could be a natural source of YTX and used for pharmaceutical purposes.