Authors:O. Farkas, Gyöngyi Gyémant, Gréta Hajdú, S. Gonda, P. Parizsa, T. Horgos, Ágnes Mosolygó and G. Vasas
Waterbloom samples of Microcystis aeruginosa and Planktothrix agardhii were collected from a variety of ponds, lakes and reservoirs in Hungary. Samples were tested with matrix-assisted laser desorption/ionization — time-of-flight mass spectrometry (MALDI-TOF MS) to identify the microcystin forms. The concentration of the microcystins was measured with capillary electrophoresis and the toxicity was tested by sinapis test. DNA was extracted from the samples and tested using a range of primers linked to the biosynthesis of microcystin. All of the fourteen collected samples gave positive results for the presence of the mcy genes with PCR products with sizes between of 425 and 955 bp, respectively, indicating the presence of the genes implicated in the production of microcystins. The results showed that a wide range of microcystin (MC) forms were detected in the Microcystis containing samples, among which MC-LR, -RR, and -YR were the most common. The highest MC concentration was 15,701 mg g−1, which was detected in an angling pond. The samples containing Planktothrix agardhii were less toxic, and the most common form in this species was the Asp3-MC-LR.
This paper reports results from light and scanning electron microscopic study of a freshwater dinoflagellate considered as a new species for the science, Peridiniopsis keveisp. nov. It was found during the last ten years in different lake, rivers, canals in Hungary and some European countries. it frequently appeared as a water-bloom forming species. The theca morphology and and plate structure analysis of this dinoflagellate established its identity as a new species. P. kevei Grigorszky et Vasas is discussed in the paper in comparsion with related taxa, moreover data about its occurrence and ecology.