Influense of various forms of iron on growth of Chlorella vulgaris Beijer culture

A comparative study of the toxic effect of magnetic nanoparticles of iron oxide (MNPs) and ions of bivalent and trivalent iron in the composition of sulfates on the growth of an intensive culture of Chlorella vulgaris Beijer is provided. The high sensitivity of the introduced biotest is shown for the case of a standard toxicant (potassium dichromate). Using the probit-analysis, and semi-extincting specific growth rate of EC50 culture concentrations were established in four-day experiments, which amounted to 1.3 ± 0.2 mg/l for potassium dichromate, 0.8 ± 0.1 mg/l for ferrous iron, 2.0 ± 0.2 mg/l for trivalent 1 and for MNPs iron oxide - 13 ± 1 mg / l. The probit analysis features and the significantly lower semi-suppressing specific growth rate of the culture in experiments with MNPs compared with ionic iron suggests a possible manifestation of other forms of exposure that are not related to the mechanism of chemical intoxication. © Published under licence by IOP Publishing Ltd.Russian Science Foundation, RSF: 18-19-00090In part this research was supported by the Russian Science Foundation (grant number 18-19-00090). We would like to thank I.N. Egorova, O.M. Samatov, A.M. Murzakaev and I.V. Beketov for very special support

PROBLEMS OF USING MOLECULAR-GENETIC METHODS FOR THE STUDY OF FISH FEEDING

The aim of the study was an approbation of molecular-genetic methods for an analysis of contents of fish stomachs of Abyssocottus korotneffi Berg, 1906, as an example.Methods. Sampling carried out at the board of the research vessel «G.Yu. Vereshchagin» in August 2017 in the northern basin of Lake Baikal. To study a fish feeding, testing of a DNA extraction methods and PCR conditions was performed. A fragments of the CO1 gene were amplified from total DNA isolated from the contents of the fish stomachs. The composition of food was studied based on the analysis of nucleotide sequences cloned into the plasmid pJET vector.Results. One species of amphipods closest to Odontogammarus calculator Dybowsky, 1874 was detected in fish food. In addition, sequences of cottoid fish were found in the studied samples. To date, information about a presence of fish in the food spectrum of this species was absent.Conclusions. The main problem of using molecular-genetic methods in studies of fish food spectrum is not enough number of data of voucher sequences of the CO1 gene of Baikal organisms in the genetic databases. Despite on advantages of analysis of the CO1 gene in studies of fish food feeding, this approach does not allow to distinguish between organisms of the same species