Growth Pattern and β-Carotene Production of Dunaliella salina Cells in Different Salinities

Subject Areas : Microbiology

S.A.  Hashemi ¹ (M. Sc. Graduated of the Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.)
F.  Pajoum Shariati ² (Assistant Professor of the Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran)
H.  Delavari Amrei ³ (Assistant Professor of the Department of Chemical Engineering, University of Bojnord, Bojnord, Iran.)
A.  Heydarinasab ⁴ (Associate Professor of the Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.)

Received: 2019-10-04 Accepted : 2019-10-04 Published : 2019-09-23

Keywords: Beta-carotene, Dunaliella salina, Microalgae, Salinity,

Abstract :

Introduction: Dunaliella salina is a green unicellular eukaryote microalga which has no cell wall in its cell structure. In the normal condition of growth it has green color but under stress situation such as high salinity, high light intensity and nutrient deficiency. it turns to yellow. In this state, the cells produce a high amount of the second metabolite such as beta-carotene, glycerol, etc. to maintain their viability. These second metabolites have a high economic value with many applications in the food industry (natural colorant), pharmaceutical industry (pro-vitamin A) and use as additives to food and feed. Nowadays with the significant increase in the world population, it seems necessary to exploit the new alternative sources for energy and food requirement. Microalgae with their unique specifications could be an excellent choice. Materials and Methods: In this study, the optimum NaCl concentration for the growth of Dunaliella salina which was purified from Urmia Lake was investigated. Dunaliella salina cells were cultivated under 10000 lx white light intensity within modified Johnson medium. Furthermore, the amount of beta-carotene accumulated within microalgae cells due to 11 steps of 0.5 M salt stresses was measured. Results: The optimum salt concentration related to the maximum biomass production was recorded in 1 M salinity. The highest amount of beta-carotene was 36.64 µg per ml of cell culture medium in 3.5 M salt concentration. Although beta-carotene content has a descending procedure by salt addition, these amounts were considerable till 6.5 M salinity of the culture medium. Conclusion: The culture condition can approach to the natural condition by application of salt in jection in small concentration.  In this condition, a significant amount of beta-carotene can be accumulated within the Dunaliella salina cells.  

References:

Ben-Amotz, A. (2004). Industrial production of microalgal cell-mass and secondary products, major industrial species, Dunaliella. In: Richmond A, editor. Handbook of microalgal culture: biotechnology and applied phycology. Oxford: Blackwell Publishing Ltd.

Ben-Amotz, A. )1980(. Glycerol production in the alga dunaliella, in: A.S. Pietro (Ed.), Biochemical and Photosynthetic Aspects of Energy Production, AcademicPress. pp. 191–208.

Borowitzka, M. &  Siva, C. )2007(. The taxonomy of the genus Dunaliella (Chlorophyta, Dunaliellales) with emphasis on the marine and halophilic species. J. Applied Phycology, 19, 567-590.

Borowitzka, M. A., Borowitzka, L. J. & Kessly, D. (1990). Effects of Salinity Increase on Carotenoid Accumulation in the Green Alga Dunaliella Salina. Journal of Applied Phycology, 2, 111-119.

Carmichael, W. W. )1992(. Cyanobacteria secondary metabolites the cyanotoxins. Journal of Applied Microbiology, 72, 445–459.

Cifuentes, A. S., Gonzalez, M. A. & Parra, O. O. (1996). The Effect of Salinity on the Growth and Carotenogenesis in Two Chilean Strains of Dunaliella Salina Teodoresco. Biological Research, 29, 227-236.

Edge, R., McGarvey, D. J. & Truscott, T. G.  )1997). The carotenoids as antioxidants, a review. J. Photochem. Photobiology, 41, 189–200.

Garcı´a, F., Freile-Pelegrı´n, Y. & Robledo, D. (2007). Physiological characterization of Dunaliella sp. (Chlorophyta, Volvocales) from Yucatan, Mexico. Journail of Bioresource Technology, 98, 1359–1365.

Glenn, E. P., Brown, J. J. & Blumwald, E. (1999). Salt Tolerance and Crop Potential of Halophytes. Critical Reviews in Plant Sciences, 18, 227–255.

Hadi, M. R., Shariati, M. & Afsharzadeh, S. (2008). Microalgal Biotechnology: Carotenoid and Glycerol Production by the Green algae Dunaliella isolated From the Gave-Khooni Salt Marsh, Iran. Biotechnology and Bioprocess Engineering, 13, 540-544.

Johnson, E. A. & Schroeder, W. A. (1996). Microbial Carotenoids.  Advances in Biochemical Engineering Biotechnology, 53, 119–178.

Madadkar Haghjou, M. (2011). Induction of Paraquat Tolerance in Dunaliella by Using Some Pretreatments. Journal of Plant Biology, 10, 71-78.

Morowvat, M. H. & Ghasemi, Y. (2016). Culture medium optimization for enhanced β-carotene and biomass production by Dunaliella salina in mixotrophic culture. Journal of Biocatalysis and Agricultural Biotechnology, 7, 217-223.

Pour Hosseini, R., Tavakoli, O. & Sarrafzade, M. (2017). Experimental optimization of SC CO₂ extraction of carotenoids from Dunaliella. Journal of Supercritical Fluids, 121, 85-95.

Richmond, A. (1986). Cell response to environmental factors. In: Richmond, A. (Ed.), CRC Handbook of Microalgal Mass culture. CRC Press Inc., Florida. pp. 89-95.

Skjånes, K., Rebours, C. & Lindblad, P. (2012). Potential for green microalgae to produce hydrogen,pharmaceuticals and other high value products in a combined process. Critical Reviews in Biotechnology, 144.

Soeder, C. J. (1986). A historical outline of applied algology. In Handbook of Microalgal Mass Culture; Richmond, A., Ed.; CRC Press: Boca Raton, FL. pp. 25-41.

Tammam, A. A., Fakhry, E. M. & El-Sheekh, M. (2011). Effect of salt stress on antioxidant system and the metabolism of the reactive oxygen species in Dunaliella salina and Dunaliella tertiolecta. African Journal of Biotechnology, 10, 3795-3808.