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In order to determine effects of chicken and cattle manures in culture of Chlorococcum, an experiment was designed in six treatments including; 0.1, 0.4, 0.8 g/l of chicken manure and 0.1, 0.4, 0.8 g/l of cattle manure as completely randomize design with three replicates for 28 days. Results showed that the mean maximum density (87.1 × 10⁵ cell/ml), specific growth rate (0.054 day^-1), algal dry biomass (0.644 g/l), and chlorophyll a (9.42 mg/l) were obtained with 0.8 mg/l chicken manure. In order to compare performance of these manures with other culture media, second experiment with five treatments including; BBM (control) (Bold’s Basal Medium), BBM + soil extract, 0.8 g/l chicken manure, 0.8 g/l cattle manure and mixture of all treatment (BBM, BBM + soil extract, chicken manure and cattle manure) was designed as completely randomize design with three replicates for 15 days. Comparative results showed that BBM + soil extract had highest algal density (11.6 x 10⁶ cells/ml), highest algal dry biomass (0.81 mg/ml), maximum SGR (0.13 /day), highest chlorophyll a (10.15 mg/l) and minimum doubling time (4.97 days). In conclusion, performance of BBM + soil extract was better in terms of biomass and growth parameters of Chlorococcum.

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In a completely randomized design, the effects of heavy metals of Cd, Cu, Pb and Ni at concentrations of 0, 5, 50 and 100 mg/l on chlorophyll a and biomass in green algae Scenedesmus quadricauda were investigated for 14 days under laboratory conditions of 23 °C, 12 h light: 12 hours light and light intensity of 60 mol photons/m²/s. The lowest density, chlorophyll a and dry biomass obtained at 100 mg/l in all of the heavy metals. The mean (±SE) highest increasing rates of chlorophyll a were 24.2±1.1, 23.1±0.8, 36.7±1.4 and 35.5±1.2% for Cd, Cu, Pb and Ni, respectively. Correspondingly, the reduction rates based on dry biomass were 51.5±3.1, 35.2±1.1, 47.9±1.6 and 56.6±2.8% for Cd, Cu, Ni and Pb, respectively. The results showed that heavy metals made significant reduction on chlorophyll a and dry biomass in S. quadricauda.

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Research subject:
Zinc is one of the most dangerous organic components in industrial wastewaters, which pollutes the environment as a result of human activities and various industrial operations. In the present study, the adsorbent prepared from Gracilaria Corticata algae was used for the first time to recover and remove heavy metal zinc and equilibrium study of the process were done.
Research approach:
In the current work, the effect of important parameters such as initial pH of solution, adsorbent dosage and contact time were investigated on the adsorption efficiency of the process. Additionally, Langmuir and Freundlich two-parameter adsorption isotherm models were used to model the equilibrium of zinc adsorption.
Main results:
The results showed that according to the calculated correlation coefficient, Freundlich isotherm was better than the Langmuir in fitting the experimental data. The highest point-to-point correlation coefficient for adsorbent percentage was achieved at 3 g/ml adsorbent dosage with contact time of min 360 and pH=7 and the lowest one was at 4 g/ml adsorbent dose with contact time of min PH=360 and 7. However, the highest adsorption rate was observed for the adsorbent dosage of 4 g/ml with contact time of 420 min at pH=9 and the lowest adsorption percentage was achieved at the adsorbent dosage of 2 g/ml with contact time of 300 min and pH=5. The maximum and minimum adsorption percentages were 76.88 mg/g and 49.25 mg/g, respectively

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The antibiotic properties of eight cyanobacteria (blue-green algae) species from Anzali Wetland was investigated on several bacterial species through vacuum distillation and simple mechanical methods. The result showed that Anabaena sp., A. variabilis, A. flos-aquae and Aphanizomenonflos-aquaehad negative effect on the growth of Staphylococcus aureusandA. flos-aquaeand A. oscillaroideshad negative effects on the growth of E. coli. The growth of Candida albicans yeast was greatly reduced by Aphanizomenonflos-aquae, A. variabilis, and A. oscillaroides. Among the investigated algae only A. oscillaroides could reduce the growth of Pseudomonassp. 

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The antibacterial and antioxidant activities of methanol and acetone extracts of three marine algae, including Hypnea hamulosa, Gracilaria corticata and Enteromorpha intestinalis wereinvestigated.Antioxidant activities were determined by means of total antioxidant capacity, total phenolic compounds, DPPH radical scavenging activity and ferric reducing antioxidant power. Antibacterial activity was determined using a paper disc diffusion method against pathogenic bacteria, including Listeria monocytogenes, Escherichia coli and Bacillus subtilis. Acetone extract of E. intestinalis showed the highest antioxidant activity and contained the highest phenolic compounds. The highest percentage of DPPH radical scavenging activity was observed in the methanol extract of H. hamulosa (p<0.05). The highest ferric reducing antioxidant power was observed in the methanol extract of Glacilaria (p<0.05). The strongest inhibition (p<0.05) against L. monocytogenes was shown by the methanol extract of E. intestinalis and the highest inhibition against B. subtilis and E. coli was observed in the acetone extract (p<0.05). In conclusion, E. intestinalis extracts showed favorable antioxidant and antibacterial activity suggesting its application in food and pharmacological industries.

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 The effect of vitamins C and E in enhancing the shelf life of the algal paste during 12 weeks cold storage (4^°C) was assessed. The microalga, Nannochloropsis oculata, was grown in Conway media under 24ºC temperature, 25ppt salinity, and continuous light intensity of 1000- 2000 lux with) and harvested at the logarithmic phase by cream separator  centrifugation at 12000 rpm in the form of paste. The algal cell viability was determined by Evans blue dye. The algal paste samples were treated with different vitamin treatments, including: vitamin C and E (0.1%w/w), and an equal proportions of mixed vitamin E and C, and then stored in refrigerator for two months. The results showed that the 95% cell viability of vitamin C treated paste was significantly higher than the control group (p>0.05).  FFA and pH in vitamin C treated group was lower than the control treatment. The comparsion of between different treatments during the storage period indicating that it contains vit E had a slower increase than the other treatments in during the storage the time. Overall, it was demonstrated that vitamins functioned as suitable preservatives for the microalgal paste in cold storage (4 ^°C).

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Aims: Karun River, which is the largest river in Iran, represents a unique ecosystem. However, increased anthropogenic activities result in the formation of this river is seriously affected by a large range of pollutants especially the heavy metal pollutants which may be toxic to human and aquatic fauna. Therefore, there is a need for continuous monitoring of pollution levels in the river.
Materials & Methods: In this study, water, sediment, and algae samples were collected from six different stations along the course of the river in September 2015 to investigate the quality of Karun’s River in terms of heavy metals (Pb, Zn, Cr, and Cd) at the basin of drinking water treatment in Ahwaz and Mollasani cities. After drying and digestion of samples, heavy metal concentrations were determined using an atomic absorption spectrophotometry (Perkin Elmer-Analyst 300).
Findings: The highest concentration of trace metals was found in sediment samples with Zn having the highest mean concentration values in all stations. The heavy metal concentrations in the downstream indicated an increase in the pollution load due to the flow of water from upstream to downstream of the river resulted in the movement and accumulation of all contaminants to the river in the downstream; hence, there was the highest concentration
of metals in basin of the Kut Abdollah treatment (downstream) and the lowest in Mollasani (upstream).
Conclusion: Comparison of the concentration of metals in the sediments with some universal standards including EPA3050 and the criterion of sediments quality standard from NOAA and Canadian Environment Agency showed that the concentration of chromium and cadmium in stations was higher than the allowable limit of EPA3050 standards and some environmental standards of Canada among all metals. Since algae samples have been able to accumulate a significant amount of heavy metals, therefore, these are suitable bio-indicators to determine the concentration of heavy metals in this aquatic ecosystems.

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In this study five diets were formulated to investigate the effects of different levels of dietary Gracilaria pygmaea powder on growth performance, feed, apparent digestibility of and water stability in juvenile Litopenaeus vannamei. Four formulated diets with three different levels of G.pygmaea (GL5, Gl10, GL15%) against a control (0% G.pygmaea) were fed to triplicate groups of L.vannamei (mean initial 6/5-7gr) for 40 days. Shrimp were fed 3 times per day, to apparent satiation and amounts of diet applied were recorded. After 40 days trial, results showed that final body weight (FBW) and weight gain (WG) of shrimp fed 10% (G.pygmaea) diets were significantly higher that those of shrimp fed other diets (P<0.05). Feed efficiency ratio (FCR) of shrimp fed 10% (G.pygmaea) diet were significantly high than that of shrimp fed control 5 and 15% (G.pygmaea) diets (P<0.05). Apparent digestibility coefficients of diets were the significantly different between the shrimp groups. Survival in all treatment was 100 %. Diets containing Gracilaria meal inclusion had significant effects on diet water stability compared with the control diet. Diet containing 15% G.pygmaea had the highest water stability after 4 h (p> 0/05). The results of this study showed that diet supplemented with 10% Gracilaria has a positive effect on the diet water stability, growth performance of Litopenaeus vannamei.

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Aims: Sargassum bovianum, Polycladia myrica, and Gracilariopsis persica can be used in aquatic diets due to their significant biomass and mass production capacity for artificial rearing. The aim of this study was to investigate the effect of marine macroalgae on growth performance and immune response in rainbow trout (Oncorhynchus mykiss) fingerlings.
Materials & Methods: The present experimental study was carried out on 210 rainbow trout fingerlings, which were randomly selected and cultured in Aquatic Laboratory, Faculty of Marine Sciences, Tarbiat Modares University, Noor, in 2016. These fingerlings were placed in 7 experimental treatments, including a diet without marine macroalgae (control) and by replacing different marine macroalgae powder levels of 5% and 10% with wheat flour. Lindo 5.3 software was used to analyze food items and SPSS 20 software was used to analyze the data.
Findings: The lowest weight gain, the lowest growth factor, the lowest protein efficiency ratio, and the highest feed conversion ratio were in the treatment containing 10% Sargassum bovianum powder and it had a significant difference with other treatments. Condition factor (CF) was at the highest level in control treatment and no significant difference was observed between treatments. There was no significant difference in survival of different treatments. The highest level of serum lysozyme was in the treatment containing 5% Gracilariopsis persica powder and the highest serum hemolytic complement activity was in the treatment containing 5% Sargassum bovianum.
Conclusion: Gracilariopsis persica, Sargassum bovianum, and Polycladia myrica have no effect on the improvement of growth performance in rainbow trout fingerlings, Gracilariopsis persica and Sargassum bovianum have an impact on their immune response.

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Brown algae are a valuable source of natural antioxidant compounds, especially Phlorotannins. In this study, the effect of solvent concentration (water / ethanol) on the the amount of Phlorotannin compounds and antioxidant properties of extracts from brown alga Sargassum angustifolium were investigated. The extraction was performed by solvent method at room temperature (28-26 °C) with ethanol/ water solvent with three ratios (30:70), (50:50) and (70:30). The amount of Phlorotannin, total phenolic content, ferric reducing antioxidant power, DPPH radical scavenging activity and total antioxidant capacity of different extracts were evaluated. The results showed that the yield of Phlorotannin extraction was dependent on the solvent concentration and with increasing polarity of the solvent, its amount increased, So its amount in ethanol/ water treatment (30:70) is significantly more than the other two treatments (P<0.05). Also, the highest amount of DPPH radical scavenging activity was obtained in ethanol/ water treatments 50:50 and 70:30 which contained less Phlorotannin. Finally, it was found that the ethanol/ water treatment 30:70 of the brown alga Sargassum angustifolium was a good choice for extracting Phlorotannin compounds as a natural bioactive compound for food and medicine purposes.

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Introduction: Biofuel production from renewable resource has been extensively paid attention as a sustainable alternative for fossil fuel. As the feed of third-generation biofuels, microalgae can produce variety of lipids, proteins, and carbohydrates in large quantities and in a relatively short time. Regarding the compatibility of these microorganisms with culture diffrent conditions and independence from the seasons of the year, the rapid growth rate, absorbing carbon dioxide and improving air quality, renewablity, non-competing with food supplies, the existence of large quantities of lipid and carbohydrate inside their cells, and abillity of biofuels production, microalgae are known as one of the most suitable options for the biofuels production. Biofuel production from microalgae consists of several stages, including cultivation, harvesting, drying, cell disruption, extraction (lipids or carbohydrates), and the production of biofuels.
Conclusion: In the present study, by reviewing each stage of the biofuels production from microalgae, its importance and application for bioenergy production is discussed. Algal biofuel is not yet competitive with fossil fuels due to its high costs. Researchers are trying to produce economic algal biofuel by improving the growth of microalgae and enriching their reserves of oil and carbohydrates, creating genetic changes, improving the design of photobioreactros, developing harvesting and drying methods, improving methods of extracting lipid and carbohydrate, and producing valuable products.

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Despite the positive role of rotifers in many hatcheries for feeding the early stages of aquatic larvae, the lower mineral content of zinc (Zn) is one of the disadvantages of rotifer compared to copepods. Therefore, it is necessary to increase its amounts through enrichment. For this purpose, in the present study, a combination of algae Isochrysis aff. galbana and Nannochloropsis oculata were enriched with zinc sulfate for 1 and 3 hours. Due to obtaining better results in 1 hour, its effects on the growth and enrichment of rotifer were surveyed. The 1: 1 alga composition was enriched with zinc sulfate at concentrations (45, 90, and 135 mg/l). The highest amount of zinc was observed in the mixed algal enriched with 90 mg/l for 1 h, which had the highest copper amount and there was no significant difference with the control group. Also, the manganese amount was higher than the other treatments except for the control group. After feeding the rotifers with enriched algae for 1 hour, the best treatment was 45 mg/l, which also contained the second level of zinc and the first level of manganese, copper, potassium, and sodium. On the other hand, this treatment had the highest number of eggs on the peak day of reproduction treatments (third day) and its population density in the last days was not significantly different from the control group (p <0.05). Zn-enriched rotifers can be used to feed marine fish to meet the nutritional needs of aquatic larvae.

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In this study, the effect of red and blue illumination on continuous culture of two different species of microalgae and cynicocytosis was studied. Comparison of blue and red lights in the cyanobacteria, Synechocystis sp. PCC6803, showed that this specie grows very fast under red light illumination, but it has very slow growth rate under blue light exposure. In spite of huge difference in growth rate, the lipid content and the fatty acid composition of Synechocystis was approximately the same for red and blue light illumination. For microalgae, Chlorella Sorokiniana, the blue light resulted to slightly higher growth rate than the red light. The C18:3 unsaturated fatty acid content was significantly higher for red light illumination compare to blue light illumination. Overall, considering the lower energy requirement for illumination of red, this light is more efficient than blue light for cultivation of Chlorella Sorokiniana.

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The microalgal strain Aurantiochytrium sp. shy contains considerable amounts of poly-unsaturated fatty acids (PUFAs), chiefly docosahexaenoic acid (DHA) with potential pharmaceutical and health-related attributes. Effects of various concentrations of glucose, meat extract, monosodium glutamate and sea salt on the algal biomass and DHA production have been investigated in this study. Maximum algal biomass (7.1 g/l) was obtained when the culture medium contained 60 g/l of glucose, 6 g/l of meat extract, 6 g/l monosodium glutamate and sea salt at 25ppt. Lipid contents of the alga exceeded 30% of its dry cell weight, with palmitic acid and DHA as the most abundant components. When the effect of a single additive was concerned, meat extract was significantly effective, while interaction between meat extract and glucose was the most effective in comparison with other interactions (P < 0.0001). According to the results, glucose can assure more algal and fatty acids production when adequate amounts of meat extract exist in the culture medium. Optimal results attained when the ratios of glucose to meat extract and C/N concentrations were 10 and 5, respectively. Due to its remarkable growth rate and the capability to produce substantial quantities of biomass and fatty acids, Aurantiochytrium sp.shy was found to be a major source of the beneficial ingredients, whose productivity can magnify if its culture conditions is optimized using favorable blend of growth-promoting materials.
 

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One of the problems existing in microalgae production process for the food products is the lack of suitable method for harvesting the microalgae from broth. Nowadays, centrifugation is the only industrial method for microalgae harvesting and its harvesting efficiency is approximately 92%, but the cost of centrifugation is high. In this paper, a new method called electroflocculation was innovated for separation of microalgae from broth and effective parameters in increasing the efficiency of this method were investigated. For achieving this goal, first a special setup which was suitable for microalgae harvesting was designed and fabricated to simulate several harvesting parameters. Then using the designed setup, several parameters such as the mixing type, mixing intensity, current rate, distance and contact area of electrodes, time and power consumption were measured and compared. Results showed that in electroflocculation method the mechanical mixing with 100 rpm intensity and current rate of 5 A has the efficiency of 98%. One cm electrode gap and 640 cm² contact area were suitable and during 30 minutes the harvesting efficiency of 98% was achieved. The power consumption for harvesting of 1 kg microalgae was 1 kW.h for electroflocculation method which is five times less than typical centrifugation.