Growth and Carotenoid Production in Dunaliella spp. Isolated from Hypersaline Habitats in the Region of Essaouira (Morocco): Effect of NaNO3 Concentration

Abstract

Abstract:In order to determine the impact of nitrogen deficiency in medium, growth rate and carotenoids contents were followed during 15 days in two strain Dunaliella spp. (DUN2 and DUN3), isolated respectively from Azla and Idao Iaaza saltworks in the Essaouira region (Morocco). These microalgae were incubated at 25 ± 1 °C with a salinity of 35‰ and continuous light in four growth media with different concentrations of sodium nitrate (NaNO 3 ): 18.75 g/L, 2.5 g/L, 37.5 g/L and 75 g/L. Maximum of cell density was observed under high sodium nitrate concentration during logarithmic phase of growth. The highest specific growth rate was 0.450 × 10 6 ± 0.006 cells/mL and 2.680 × 10 6 ± 0.216 cells/mL, respectively for DUN2 and DUN3. Carotenoids production mean were not stimulated under nitrogen deficiency, and the highest content was showed in DUN2 at high nitrogen concentration (3.210 ± 0.261 μg·mL -1 ) compared with DUN3 strain.

The Effect of Rumen’s Cattle Waste as Alternative Nutrient Sources for Thalasiossira sp Aquaculture

“…This showed that the liquid cattle rumen waste enriched with NaNO3 produced a good N/P ratio for the growth of Thalasiossira sp. Previous study showed that NaNo3 (sodium nitrate) contained high concentration of nitrate and helped the growth of Thalasiossira sp [7].…”