Наукові роботи. Біологічний факультет
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Документ Relationship between nitrate and phosphate assimilation in some freshwater and saltwater algae(Kharkiv : V.N. Karazin Kharkiv National University, 2020-02-12) Komaristaya, V.P.; Комариста, Віктория ПавлівнаThe objective of this research is to study how the deficiency of nitrate affects the dynamics of phosphate acquisition and vice versa, in cultures of H. pluvialis, Ch. dissectum and D. salina at two levels of light intensity (2 and 8 klx) and two levels of salinity (1 and 4 M NaCl) for saltwater D. salina. In both freshwater species H. pluvialis and Ch. dissectum, deficiency of one of the nutrients reduced the assimilation rate of the other nutrient. As for the saltwater D. salina, a similar effect of suppressing the assimilation of one nutrient by lack of the other was observed only at the low salinity of 1M NaCl. An increase of salinity to 4M NaCl per se led to inhibition of the absorption of both nutrients, but a lesser degree. Noteworthy, at a salinity of 4M NaCl, a deficiency of one of the nutrients no longer affected the assimilation of the other. No statistically significant effect of increasing light intensity from 2 to 8 klx on the dynamics of nutrient absorption was observed in any of the studied species.Документ Evaluation of contribution of salinity, irradiance, and nutrient deficiency into the yield of cells and beta-carotene accumulation in the culture of Dunaliella salina (Chlorophyta)(Kherson State University (Ukraine), 2018-06) Komaristaya, V.P.; Bilousova, K.M.; Rudas, O.M.The purpose of the study was to evaluate the contribution of salinity, irradiance, nitrate and phosphate, and their interactions into the yield of cell number and beta-carotene accumulation in Dunaliella salina. To avoid confounding of the effects of factors-conditions by the depletion of factors-resources, the alga was grown in fed-batch culture. In the level ranges of the experimental factors (irradiance 2–8 klx, salinity 1–4 M NaCl, KNO3 0–80 mg L-1, K2HPO4 0–10 mg L-1), nitrate and phosphate influenced the productivity of culture by cell number and beta-carotene accumulation more strongly than salinity and irradiance. Effects of salinity and irradiance depended on nutrients and their pre-supply to the inoculum. Total effect size eta squared of nutrients on cell yield comprised 0,59 for non-starved and 0,43 for starved inoculum, whereas total effect size of factors-conditions – 0,10 and 0,12 correspondingly. As to cellular beta-carotene content, total effect size of nutrients on the cells grown from non-starved and starved inoculum was 0,71 and 0,58, and of factors conditions – 0,8 and 0,5 correspondingly. Remained variances of cell yield and beta-carotene content were attributed to the interactions of salinity and irradiance with the nutrients. The combination of high values of salinity and irradiance exerted its own, unconfounded by depletion of nutrients, but lower influence on beta-carotene accumulation. The highest beta-carotene content of 53 pg per cell was observed in the culture grown from the starved inoculum at the deficiency of phosphorus. Combination of high salinity and irradiance values yielded 17 pg of beta-carotene per cell compared to about 5 pg under the optimal culture conditions. Controlled nutrient supply would be the most powerful tool for biosynthesis control in D. salina culture.Документ Response of Dunaliella salina Teod. culture to various regimes of fed-batch nutrient supplementation(Харківський національний аграрний університет, 2016) Komaristaya, V.P.; Antonenko, S.P.; Rudas, A.N.There were studied D. salina culture growth, beta-carotene and total protein accumulation under various fed-batch regimes: supplementation of nitrate and phosphate, nitrate or phosphate solely, and after the switch of nitrate supplied culture to phosphate supplementation and vice versa. Pre-cultures, unsupplied with the both or any nutrient, accumulated beta-carotene. The sub-cultures supplied in turns with nitrogen and phosphorus, thus surviving one or the other nutrient depletion, regained culture growth ability, lost the ability to accumulate beta-carotene and started to accumulate protein. The ability to reserve the available nutrient under another nutrient deficiency was hypothesized as D. salina possible ecological strategy, including assimilated carbon storage in triacylglycerides (TAGs) and beta-carotene accumulation to prevent TAGs oxidation. The outcomes for industrial D. salina culture are discussed.Документ Nutrient stored inside Dunaliella salina cells prevents beta-carotene accumulation under its medium deficiency(Kherson State University, 2015-05-19) Komaristaya, V.P.; Antonenko, S.P.; Rudas, A.N.At alternating cultivation cycles under deficiencies of nitrogen or phosphorus D. salina culture grew limitedly at the first cultivation, then intense after transferring the culture. Cellular beta-carotene accumulated during the first cultivation, and then almost did not. D. salina cells are able to accumulate the available nutrient at the other nutrient deficiency and to spend the intracellular nutrient reserve for culture growth when the other nutrient re-supplied to the medium.