Nanochemistry and biotechnology
Features of changes in key indicators of the viability of green algae in the presence of cerium salt or nanoceria
Cheban L.M.1, Shcherbakov A.B2, Zholobak N.M.2,3
1 Yuriy Fedkovych Chernivtsi National University,
Kotsyubynsky Str., 2, Chernivtsi-58012, Ukraine.
2 D.K. Zabolotny Institute of microbiology and virology NAS of Ukraine
Acad. Zabolotny str., 154, D03680, Kyiv, GSP Ukraine.
3 Kyiv National University of Technologies and Design
Nemirovich-Danchenko str., 2, Kyiv 01011, Ukraine.
E-mail: n.zholobak@gmail.com

The biomass of microalgae due to their small size and sufficiently high content of amino acids, proteins, polyunsaturated fatty acids and carotenoids is used as an alternative balanced diet in aquaculture for feeding zooplankton and planktivorous fish [1]. It was studied the influence of cerium chloride salt or citrate-stabilized cerium dioxide nanoparticles synthesized by the method proposed by Ivanov et al. [2] at various concentrations (1 μM-100 mM) on biomass production of two green unicellular algae species Desmodesmus armatus (Chod.) Hegew and Acutodesmus dimorphus (Turpin) Tsarenko; the amount of chlorophyll, proteins and lipids in the biomass of algae was also determined.
It is shown that both nanoparticles and cerium salt in concentrations of 0.1 M and 0.01 M have a pronounced toxic effect on the studied algal cultures, which is manifested by a sharp increase in the level of lipids in biomass, a decrease in the amount of chlorophyll and protein. At lower concentrations, cerium dioxide nanoparticles increase the accumulation of algal biomass, probably due to changes in key metabolic pathways, resulting in increased accumulation of carbohydrates in the biomass. For cerium salt, these effects are less pronounced.
Thus, depending on the concentration of the used objects, it is possible to obtain an increase in the production of fodder biomass enriched in lipids or carbohydrates, correspondingly to biotechnological tasks.

1.	Villarruel-López A., Ascencio F., Nuño K. Microalgae a potential natural functional food source – a Review // Pol. J. Food Nutr. Sci.-2017.-67(4). -Р. 251-263.
2.	Ivanov V.K., Polezhaeva O.S., Shaporev A.S. Baranchikov A.E., Shcherbakov A.B. Synthesis and thermal stability of nanocrystalline ceria sols stabilized by citric and polyacrylic acids // Russ. J. Inorg. Chem.-2010.-55. -P. 328-332.