ANALYSIS OF PRO-ANTIOXIDANT STATUS OF DAPHNIA MAGNA UNDER BIOENCAPSULATION WITH UV-IRRADIATED RHODOTORULA MINUTA YEAST BIOMASS
DOI:
https://doi.org/10.31861/biosystems2026.01.125Keywords:
Daphnia magna, Rhodotorula minuta, bioencapsulation, ultraviolet irradiation, carotenoids, superoxide dismutase, lipid peroxidation, oxidative modification of proteins, live feedAbstract
Ensuring high viability and survival rates of juvenile fish during the early stages of ontogenesis is a priority task for intensive aquaculture, the solution to which is directly linked to the optimization of starter diets. Cladoceran crustaceans, particularly Daphnia sp., are a widely used live feed; however, their natural nutrient profile is often deficient in several essential compounds, including carotenoids. A promising method to address this issue is bioencapsulation technology using carotenogenic yeasts of the genus Rhodotorula, whose biosynthetic potential has been artificially enhanced via dosed ultraviolet (UV) irradiation. The aim of this study was to evaluate the effect of bioencapsulation with UV-irradiated Rhodotorula minuta yeast culture on the pro-antioxidant status and population dynamics of Daphnia magna to substantiate the prospects of using modified microbial biomass in aquaculture.Stimulation of carotenogenesis in the R. minuta strain UCM Y-1349 was performed by short-wave UV irradiation (λ = 254 nm) for 120 minutes, followed by submerged cultivation. The resulting biomass was used to feed D. magna for 16 days with a final substrate concentration of 1.5×107CFU/L. The state of the pro-antioxidant system in daphnia was evaluated by the content of TBA-reactive substances (TBARS), the level of protein carbonyl derivatives, and superoxide dismutase (SOD) activity on the 8th and 16th days of the experiment. In parallel, daily monitoring of the population size was conducted. It was established that feeding with UV-modified diet initiates a state of moderate physiological eustress in daphnia, accompanied by a 1.5-fold increase in TBARS levels and a 1.77-fold increase in protein carbonyl content compared to the native control, which is presumably due to the pro-oxidant effect of high concentrations of accumulated carotenoids. However, on the 16th day of feeding, a potent compensatory response was recorded: SOD activity in the experimental group was nearly twice as high as in the control, leading to the stabilization of lipid peroxidation processes and a 37% increase in the population size. The results of the study confirm that the biomass of UV-irradiated R. minuta yeast acts as an effective biomodulator of the pro-antioxidant status of live feeds. The induced eustress ensures an increase in their viability and substantiates the prospects of implementing this biotechnology to optimize the feed base in fish farming.
References
1. Cheban, L., Khudyi, O., Prusiñska, M., Duda, A., Khuda, L., Wiszniewski, G., Kushniryk, O., & Kapusta, A. (2020). Survival, proximate composition, and proteolytic activity of Artemia salina bioencapsulated with different algal monocultures. Fisheries & Aquatic Life, 28(3), 205–215. https://doi.org/10.2478/aopf-2020-0025
2. Chentir, I., Ben Miri, Y., Kot, A. M., Nikhanj, P., Mussagy, C. U., Arous, F., & Markou, G. (2025). Rhodotorula genus: Vast knowledge, limited commercialization – What is holding us back? Fungal Biology Reviews, 54, Article 100459. https://doi.org/10.1016/j.fbr.2025.100459
3. Goncalves, R., Pfalzgraff, T., & Lund, I. (2024). Impact of live feed substitution with formulated diets on the development, digestive capacity, biochemical composition, and rearing water quality of European lobster (Homarus gammarus, L.) larvae. Aquaculture, 586, Article 740776. https://doi.org/10.1016/j.aquaculture.2024.740776
4. Haldule, S., Singhvi, M., & Zinjarde, S. (2026). Rhodotorula and Phaffia: Pigment producing basidiomycetous yeasts for application in aquaculture practices. Archives of Microbiology, 208(3), Article 67. https://doi.org/10.1007/s00203-025-04605-8
5. Khuda, L., & Khudyi, O. (2024). Analiz kryvykh vyzhyvanosti Daphnia magna za umov inkapsuliatsii biomasoi Rhodotorula minuta [Analysis of Daphnia magna survival curves under conditions of encapsulation by Rhodotorula minuta biomass]. Biolohichni systemy, 16(1), 53–57. https://doi.org/10.31861/biosystems2024.01.053 (in Ukrainian)
6. Khuda, L., Spivak, M., Demchenko, О., Karucheru, О., Frunza, O., Khudyi, О. (2020). Probiotic correction of Daphnia magna microbial profile using Lactobacillus casei UCM 7280. Scientific Herald of Chernivtsi University. Biology (Biological Systems), 12 (1), 3-8. https://doi.org/10.31861/biosystems2020.01.003
7. Khudyi, O., Kushniryk, O., Khuda, L., Marchenko, M. (2018). Differences in Nutritional Value and Amino Acid Composition of Moina macrocopa (Straus) Using Yeast Saccharomyces cerevisiae and Rhodotorula glutinis as Fodder Substrates. Int Lett Nat Sci, 68, 27-34. https://doi.org/10.56431/p-9lbt9i .
8. Kiritsa E. (2005). The directed synthesis of carotinoids by yeasts and the perspectives of its use: Dissertation of Dr. in biology. Chisinau, 2005, 129 p.
9. Kraievska I.M., Vasina L.M. (2017). Dynamika nakopychennia biomasy i karotynsyntezuiucha aktyvnist Rhodotorula glutinis (Fresenius) F. C. Harrison (1982) za dii ultrafioletu [Dynamics of biomass accumulation and carotene synthesizing activity of Rhodotorula glutinis (Fresenius) F.C. Harrison (1982) under the action of ultraviolet radiation] – Biolgical Systems 9: 183-186 (in Ukrainian)
10. Melaku, S., Geremew, A., Getahun, A., Mengestou, S., & Belay, A. (2024). Challenges and prospects of using live feed substitutes for larval fish. Fisheries and Aquatic Sciences, 27(8), 475–487. https://doi.org/10.47853/FAS.2024.e45
11. Ohkawa, H., Ohishi, N., & Yagi, K. (1979). Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Analytical Biochemistry, 95(2), 351–358. https://doi.org/10.1016/0003-2697(79)90738-3
12. Radhakrishnan, D.K., AkbarAli, I., Schmidt, B.V., John, E.M., Sivanpillai, S., Vasunambesan, S.T. (2020). Improvement of nutritional quality of live feed for aquaculture: An overview. Aquac. Res., 51, 1–17. https://doi.org/10.1111/are.14357
13. Reznick, A. Z., & Packer, L. (1994). Oxidative damage to proteins: Spectrophotometric method for carbonyl assay. Methods in Enzymology, 233, 357–363. https://doi.org/10.1016/S0076-6879(94)33041-7
14. Samat, N.A., Yusoff, F.M., Rasdi, N.W., Karim, M. (2020). Enhancement of Live Food Nutritional Status with Essential Nutrients for Improving Aquatic Animal Health: A Review. Animals, 10, 2457. https://doi.org/10.3390/ani10122457
15. Sun, M., Zigman, S. (1978). An improved spectrophotometric assay for superoxide dismutase based on epinephrine autoxidation. Analytical Biochemistry, 90(1), 81–89. https://doi.org/10.1016/0003-2697(78)90010-6
16. Vasina, L., Kraievska, I., Khudyi, O., Khuda, L., & Cheban, L. (2020). Application of an association of yeast and lactic acid bacteria to bioencapsulate carotenoids in Daphnia magna (Straus, 1820). Fisheries & Aquatic Life, 28(4), 225–233. https://doi.org/10.2478/aopf-2020-0027
