Some species of the genus DUNALIELLA are the major primary producers in Maharlu salt lake, which is polluted with different heavy metals including Hg2+. Short-term (48 h) and prolonged exposure (28 d) of D. TERTIOLECTA to 5, 10, 20, and 50 mM HgCl2 decreased Chlorophyll "a" content, but caused enhanced carotenoid production and increased ascorbate peroxidase (APX) activity, both of which function as antioxidants, buffering oxidative stress by scavenging reactive oxygen species (ROS). Increase in total carotenoids in terms of pictogram per cell (pg cell-1) was higher in prolonged exposure, whereas APX activity was greater in shortterm exposure to HgCl2. In both experiments, despite the increase in antioxidant capacity, algal growth in terms of cell number per ml of culture decreased relative to the control. It seems that generation of ROS in the presence of HgCl2 exceeds the total antioxidant capacity of the cells, which is evident from the increase in cell malondialdehyde (MDA) content and, as a result, reduced cell number. The SDS-PAGE profile of the extracted proteins showed enhanced synthesis of two protein bands of about 29 and 38 kD.

In this study, increase of cell density of DUNALIELLA tertioletca was evaluated by four cultivation mediums including Conway, Guillard, Sato and TMRL mediums in the same conditions, including the amount of light 2000 to 5000 lux, temperature at 22. 5-24 degrees Celsius, salinity 25 ppt, pH 8. 5 and the same 24-hour aeration for 16 days. The results showed that among the four mediums with different chemical components, the highest rate of increase in cell density obtained in TMRL medium (P<0. 05), although the cell density rates that obtained in Conway and Guillard medium were not different significantly (P>0. 05), but increase of cell density in algae in Sato medium was less than the other treatments (P>0. 05). Therefore, we can pull a result that Guillard, TMRL and Conway mediums are suitable for increase of cell density in this algae species in vitro, although TMRL medium usually is used for outdoor algae cultivations.

The purpose of this study was to evaluate the potential of deep aquifer well water located in Sistan region (southeastern of Iran) for growing DUNALIELLA TERTIOLECTA. For this purpose, 5 treatments including deep aquifer well water with salinities of 20 and 35ppt, deep aquifer well water and salt of Urmia Lake (35 ppt) and tap water with salinities of 20 and 35ppt were considered and                                 D. TERTIOLECTA microalgae was reared for 24 days under standard conditions (temperature 26±1ºC, light 2000 lux, 16 hours light and 8 hours darkness). The results showed that the pH value in all treatments increased slightly until day 6 but then decreased and had a steady trend from day 12 to 24. The highest amount of growth, chlorophyll a and carotenoid production, specific growth rate, the least doubling time and the highest rate of division were observed in deep aquifer well water treatment (salinity 20 ppt), although the lowest amount of biomass production was in this treatment. Based on these results, it can be said that if salt is added to deep aquifer well water, by changing the composition and increasing salinity, the amount of biomass produced will increase. In general, D. TERTIOLECTA can be grown in deep aquifer well water (No. 1) extracted in Sistan region

Carotenoids are widely used in nutraceutical, additives and cosmetics as colorants and antioxidants. DUNALIELLA is the main natural source which accumulates massive amount of carotenoids. This study examines the effect of different concentrations of NaCl (0.3M to 2M) and light intensities of 50 and 150 μmol/m²s on total carotenoids accumulated by DUNALIELLA TERTIOLECTA (DCCBC26), from Urmia lake (North West of Iran) compared to those obtained from DUNALIELLA salina CCAP 19/18 and also the wild type DUNALIELLA salina WT strains. In all microalgaes production of carotenoids were triggered by increase in light intensities. Changes of intensity from 50 μmol/m²s to 150 μmol/m²s led to 2.4, 2.1 and 1.4 folds of carotenoids production by D. salina CCAP, D. salina WT and D. TERTIOLECTA respectively. In both salina strains carotenoids production improved with higher salinity picking at salt concentration of 2M, while D. TERTIOLECTA showed optimum carotenoids production at 0.7M.        

In this study, effects of the different concentrations of Iron (0, 144, 244 (control), 444, 644 gl-1) and phosphate (0, 0.015, 0.025, 0.075, 0.1 gl-1) on the vitamin E production in DUNALIELLA TERTIOLECTAin 45 days period examined. The results showed that in compare with control in 644 gl-1 Iron treatment vitamin E increased and in 0 gl-1 significantly decreased. As well as, in 0.1 gl-1 phosphate vitamin E content increased and in 0 gl-1 Pi decreased.

In this research effect of Azadirachta indica (Juss) seed extract upon predator ciliates in intensive unicellular algal mass culture of DUNALIELLA TERTIOLECTA (Butcher) under laboratory condition were studied. For this propose, LC 100 of ciliates and EC 50 algae in the optimum Lab. condition were examined. Results show that a 24-h LC 100 at 4mg/l seed extract was found for the ciliate whereas at 24h EC50 10 mg/l had the best result for the ciliate. But at investigation of seed extract effect upon the of unicellular algae and ciliate both to gathers at one contaminated sample show that The application dose for use of this extract with useful effect in completely elimination of ciliates is over than 4 - 5 mg/l. Finally study in long time effect of seed extract upon the mortality, motion and body shape of algae cells showed that this extract is able to recover contaminated algal population and had no harmful effect on the algae cells at 72 hour.

DUNALIELLAis a green halotolerant microalga, which has several industrial applications e.g. b-carotene production. Identification of different DUNALIELLA species has been carried out by morpho-physiological and recently molecular studies. To achieve an improved understanding of taxonomy, these studies are required to be in linkage. The present study describes molecular and specific morpho-physiological properties of a DUNALIELLA isolate obtained from Gavkhooni salt marsh in Iran. Phylogenetic analysis of Internal Transcribed Spacer region demonstrated that the isolate was associated with different species except D. salina (CCAP 19.18 and 19.30) and D.viridis.18S rDNA size of the isolate was identical to that of D. TERTIOLECTA and intron-lacking strains of D. salina.18S rDNA fingerprint profile and phylogenetic analysis revealed D. TERTIOLECTA as the closest taxon to the isolate. Features of optimum growth salinity (1.5-3% w/v) and maximum carotenoid per cell (0.7 pg cell-1) were comparable with reported data for D. terrtiolecta. Morphological characteristics including the size and color of the cells, presence and location of stigma and refractile granules were similar to those of D. TERTIOLECTA. Totally, considering molecular and morpho-physiological properties, the isolate was attributed to the species D. TERTIOLECTA and was named as DUNALIELLA TERTIOLECTA ABRIINW-G3.

This study was performed to compare the efficiency of six microalgae namely DUNALIELLA TERTIOLECTA, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorellasp. and Spirolina sp. on the growth, survival rate and reproduction efficacy in Artemia urmianain laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the f/2 culture medium.Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. A highly significant difference (p<0.01) were found among three microalgae in terms of length growth, survival rates and reproduction characteristics in A. urmiana. In spite of higher length growth of A.urmiana fed on N. oculata than A. urmianafed by T. suecica but survival and reproduction in the latter was better than the first treatment. In general, D. TERTIOLECTA was more efficient than other microalgae examined in the present study onA. urmiana concerning not only to growth and survival but also to reproduction mode. So, it is preferred to feedA. urmiana.

This study was performed to compare the efficiency of 6 microalgae namely DUNALIELLA TERTIOLECTA, Tetraselmis suecica, Chlorella sp., (green algae), Nannochloropsis oculata, Spirolina sp. (blue-green algae) Cheatocerus sp. (Diatoma), and Isochrices sp. (Haptophytae) on the growth, survival and reproduction efficacy in Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the F/2 Guillard's culture medium. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. Length growth of A. urmiana was measured in three-day intervals. To determine reproduction efficiency characteristics such as cysts production, intervals between two successive reproductions, first reproduction time and the date of female Artemia were analyzed. The results indicated a significant difference (p<0.001) among three microalgae in terms of length growth, survival rates and reproduction characteristics in A.urmiana. There was a direct relationship between Artemia length growth and reproductive characteristics. This study showed that survival rate, length growth and reproductive characteristics of A.urmiana fed by DUNALIELLA TERTIOLECTA were significantly higher than A.urmiana fed by other microalgae. It seems that Artemia culture in salt water with DUNALIELLA as natural flora is a suitable choice.