فهرست مطالب فرناز رفیعی

Red seaweeds contain compounds such as agar and hormones that have many uses in industry. This research was done to determine biomass and extract two hormones and agar from Gracilaria corticata algae. Methods Sampling was done from December 2014 to November 2015 in Bushehr port, one month apart. Biomass and environmental parameters were measured and algae harvested in the selected transect. After the extraction steps, hormones are separated by the HPLC method and identified by standard injection. The highest amount of agar occurred in July with 63.3%, Zeatin in September with 21.9% and indole butyric acid with 19.21% in January. The highest fresh weight of this algae was measured in March at 423.33 grams per square meter. The results of the ANOVA and Chi-squared statistical tests showed a significant difference in 6 months of sampling in all samples (P<0.05). The amount of agar showed a significant correlation with the biomass. Also, among environmental factors, agar was correlated with salinity and temperature. Butyric indole of acid in January caused the growth of alga, but Zeatin did not show a significant effect on the growth of this species. In general, in order to extract these materials, harvesting can be done in the months that have the highest amount. Considering the exorbitant price of these hormones and the need to use them in algae extracts and algae liquid fertilizer, this research is a starting point for extracting all kinds of hormones from these algae.

Brown seaweeds contain compounds such as alginate and phytohormones that have many uses in industries. This research was conducted to determine biomass and extract two phytohormones and alginate from Sargassum muticum. Sampling was done from January 2014 to November 2015 in Bushehr port, one month apart. Biomass and environmental parameters were measured in the selected transect and the algae were sampled. After extraction, hormones were separated by HPLC and identified by standard injection. The highest biomass of alga was in January (679±2.12g/m2) and the lowest was in September (20.67±0.76 g/m2). Alginate reached the lowest leve (40.67±1.03%) in November and the highest level (54.67±2.25%) in January, which had a positive correlation with biomass. The highest amount of gibberellin (5.86±1.11%) was in July, which had a positive correlation with temperature. Zeatin was obtained only in May (0.18±0.07%). According to the results, in order to extract alginate, gibberellin and zeatin from this alga, it should be done in January, July and May, respectively. Considering the high price and the necessity of using these materials in industries, agriculture and as algae liquid fertilizer, this research is a starting point for extracting substances and hormones from this alga.

In tobacco, chemical fertilizers are used to achieve the desired yield like other crops. In recent years, with the aim of maintaining soil fertility, improving physical and chemical properties, and creating a balance in environmental factors, the use of biofertilizers and compounds such as biochar has been considered in line with the goals of sustainable agriculture. Biochar improves soil's physical and chemical properties, increases microbial activity, and provides microorganisms with carbon, energy, and mineral elements. The positive effects of using biochar with some beneficial microorganisms can be intensified. In some studies, the effect of biochar on the abundance of arbuscular mycorrhizal fungi and the positive effects of these in increasing yield have been reported. Mycorrhizal fungi can be considered a suitable solution to improve the plant's nutritional status by absorbing nutrients and more water, decomposing soil organic matter and improving the growth and development of host plants. Mycorrhizal fungi can increase water uptake by entering very small pores that even the plant roots cannot penetrate. Applying other useful soil organisms such as Azotobacter in tobacco fields due to its ability to dissolve phosphates and produce vitamins can improve plant growth and development. Considering that no research has been done in Iran on tobacco production without chemical fertilizers, in this study, the possibility of economic production of tobacco using biofertilizers and modifying compounds such as biochar is evaluated.

This experiment was carried out as a factorial based 3×2×2 on randomized complete block design including biochar (B) at three levels (0, 4, and 8 ton/ha), mycorrhiza (M), and Azotobacter (A) at two levels (without and with application) with four replications. The seedling roots of Azotobacter-containing treatments were inoculated ten days before transplanting. Also, mycorrhiza inoculum was mixed with the soil bed in a ratio of 1 to 10. The biochar was also distributed manually on the surface of the plots and mixed with field soil by a disc. The total weight of four picks of each experimental plot was calculated as fresh yield and after curing as dry plot yield. The leaf nitrogen content was measured by the Kjeldahl method, phosphorus was measured by spectrophotometer, and the amount of absorbable potassium was measured by reading potassium ions by flame photometer. Phillips and Hayman's (1970) method was used to calculate the mycorrhizal symbiosis of the root. The nicotine and sugar content was determined using the standard method Nos. 35 and 38 of the world organization of Corseta. 

Application of 4 ton/ha biochar increased fresh yield by 11%, cured yield by 12%, the leaf nitrogen, phosphorus, and potassium content by 13, 20, and 15%, respectively, and leaf nicotine and sugar content by 18 and 24% compared to zero level. The leaf nitrogen enhanced by increasing biochar consumption level. The highest amount of leaf nitrogen was obtained at the B8. The same trend was observed in leaf phosphorus content. But in terms of potassium content, the lowest amount was obtained at B0 with 2.6% and the highest at B4 with 3%. Application of mycorrhiza inoculum increased the fresh and dry yield by 6%. The positive results of this study in the simultaneous use of biochar and mycorrhiza and Azotobacter on the mycorrhizal symbiosis can be due to the positive effect of biochar in increasing the activity of other microorganisms such as mycorrhiza or reducing the negative effects of harmful chemical compounds in soil. In this study, although using Azotobacter increased the leaf yield, this increase was not significant. Also, the Azotobacter application had a positive and significant effect on nicotine content and increased it by 32%. The application of Azotobacter can be a desirable solution to increase tobacco nicotine content. 

Due to the lack of significant differences between 4 and 8 tons per hectare of biochar on the evaluated traits in terms of economic aspects, the use of 4 tons per hectare of biochar along with the use of mycorrhiza and Azotobacter to achieve acceptable yield while maintaining chemical quality in tobacco farms is recommended.

In the present study, two regulatory phytohormones, abscisic acid and auxin, were extracted from two different macroalgae, Sargassum muticum and Gracilaria corticata, for the first time. Sampling was performed each month with three replicates, from Bushehr Province shores located in the north region of Persian Gulf for six alternative months. The alteration of seaweeds biomass and the probable impacts of some environmental factors were measured. The extracted phytohormones were isolated employing HPLC method and identified by injection of standards. The highest amount of ABA phytohormone in the two species, occurred in November. Also, the highest amount of Auxin in Sargassum muticum was reported in May, while the highest amount of this hormone in Gracilaria corticata was observed in January. In January, the maximum mean biomass in Sargassum muticum was 679gr/m2, while the minimum mean of 20.66gr/m2 was observed in September. Moreover, the highest average biomass in Gracilaria corticata was 423/33gr/m2 in March and the lowest mean of 158g/m2 was reported in November. ANOVA and Chi-squared test results showed a significant difference in all samples. These phytohormones could be applied in preparing algae liquid fertilizer in future studies.

In this study, some biochemical compounds taxa of brown algae, belonging to 5 different genera in Lengeh port, Hormozgan province, including Sargassum vulgare (C. Agardh, 1820), Padina australis (Hauck, 1887), Cystoseira myrica (C. Agardh, 1820) Colpomenia sinousa (Derbes & Solier, 1851) and Iyengaria sp. (Borgesen) were studied in winter (February 2019) and summer (July 2018) and algae were collected at low tide. Extraction of protein was performed by Lowry method, lipid by Freeman method, carbohydrate by phenol sulfuric acid method and alginate by Istini method. The highest percentage of protein from algae Cystoseira myrica 2.7 % in February, lipid with 75 % of the algae Padina australis in February, by 3.4%, carbohydrates from algae Sargassum vulgare in February and alginate with 30% was achieved in July. The mean difference of these compounds between February and July was significant (P <0.05). According to the obtained results, considering the high amount of lipid in the algae of this study, they can be used to increase the fat content of animal milk. Also, the alginate obtained in this study has a suitable amount among the brown algae studied and it can be extracted for useing in various industries.

Tobacco is cultivated as a valuable crop in more than one hundred countries in different climatic conditions and plays an important role in the economies of some countries.This study was performed to evaluate the effect of mycorrhiza and azotobacter with application of biocahr on tobacco leaf yield, root characteristics and phytochemical components under rainfed conditions for two growing seasons at 2016 and 2017 at the Research Farm of Tirtash Tobacco Research and Education Center of Mazandaran province, Iran. A factorial experiment based on randomized complete block design with four replications and three treatments was performed. Treatments consisted of biochar (B) at three levels (0, 4 and 8 ton/ha), mycorrhiza (M), and azotobacter (A) both at two levels (without and with application). Application of 4 ton/ha biocahr increased fresh yield by 26%, cured yield 26%, root dry weight 44%, root fresh weigth 37%, root length 41%, nicotine 3%, while reduced sugar content 24% and sugar to nicotine ratio by 21% as compared to zero level of biochar application. The effect of mycorrhiza and azotobacter application on tobacco leaf yield but it was not significant, however, azotobacter had the most significant effect on nicotine content (17%). There was a positive and significant correlation between root characteristics and tobacco leaf yield. Due to the lack of significant differences between levels of 4 and 8 tons per hectare of biochar in most of the evaluated traits in terms of economic approach, the use of 4 tons per hectare of biochar along with mycorrhiza and Azotobacter to reduce the adverse of low water effects in rainfed farms and ameliorate the tobacco growth is recommended. Also azotobacter application is considered as desirable factor to increase of nicotine in tobacco.

Water resource limitation in the end of growth season of rapeseed crop is one of the main problems for production and development of this crop in semi-arid regions of Iran. Therefore, introduction of compatible and tolerate cultivar to this condition is crucial for growth expansion of rapeseed. To identify and introduce suitable rapeseed cultivar for delayed planting, a split plot experiment based on randomized complete block design with three replications at Research Field of Seed and Plant Improvement Research Institute of Karaj, Iran was conducted in 2015-16 and 2016-17. In this study, sowing dates were October 7 (normal) and November 6 (delayed planting) asseinged to the main plots, and rapeseed cultivars including ES Hydromel, ES Alonso, ES Darko, ES Lauren and Ahmadi to the sub-plots. To introduce of tolerate cultivar to drought tolerance indices, experimental plots were subjected to two common irrigation conditions (control) and irrigation interruption from the flowering stage onwards (drought stress). Combined analysis of data indicated that delayed planting significantly reduced rapeseed oil percentage and oil yield. According to the results ES Hydromel cultivar produced the highest oil percentage (41.61%) and oil yield (1381.08 kg.ha-1). Based on the selected indices of this study, including geometric mean productivity, stress tolerance index, and mean productivity, the most tolerant cultivar under both normal and delayed planting was ES Hydromel and the least tolerant cultivar under normal conditions was ES Lauren and under stress conditions was ES Darko. The results of cluster analysis also confirmed the formation of two clusters, ES Darko, Ahmadi and ES Lauren in belonged to sensitive cluster and ES Hydromel and ES Alonso to the tolerant cluster.

This research was accomplished in 2016 at greenhouse for study of effect of different concentrations of seaweed (Sargassum) extract on growth of Menthapiperita. Present research was done in a factorial design with a completely randomized four replications. The factors were different concentrations of seaweed extract with 0, 10, 20, 30 and 40 percent, different spray time in two period types of every 5 and 10 days.Results in this study showed that Sargassum extract concentrations had no positive effects on morphological characteristics including stem high, the number of shoot, number of leaves, number of nodes, fresh and dry weight.In general it can be concluded that, the use of this alga in the production of peppermint because of the decline in growth rates is not recommended and the concentration of the alga more than 20% can be used as herbicide.

Effect of temperature, irradiance and photoperiod on biomass and the alginate content of Sargassum boveanum was evaluated for 42 days under laboratory conditions. The seaweed samples were collected from coast lines of Bandae-e-Lengeh in Hormozgan province (South of Iran) in June 2009. The algae were suspended in aquariums,40.30.60 cm (20 litter) in 3 replicates. The algae were cultured under temperatures gradients ( 15,20 and 25 ºC ), irradiances levels (4700,5700 and 6700 Lux) and three photoperiods (12;12, 14;10 and 16:8 hours, Light:Dark) . The algae were weighted once a week . After 6 weeks of experiments, the algae were collected, dried and weighed. The highest biomass of S. boveanum was obtained at 25° c (48.12 gr.) ,4700 Lux (42.48 gr) 12:12, light: dark (34 gr). Maximum content of alginate (29.67%) was extracted in temperature of 25 ºC. As the results showed, mariculture of this algae should done in spring with optimum of temperature and photoperiod. The alginate content of S. boveanum in this project is high in compare with the other studies.

In order to investigate the effect of water deficit tension on different growth stages on yield, yield components and produced grain quality of sorghum seeds cultivars,  an experiments was performed as split plots based on randomized complete blocks design with four replications in Isfahan Ghiam Cultivation and Cattle Farm Company in 2017. The main factor including irrigation cut at four levels (irrigation cut from the pollination stage onwards, irrigation cut from the milking stage onwards, irrigation cut from the paste stage onwards and normal irrigation (control)) and sub-factor including three cultivars of seed sorghum (Sepideh, Kimia and Payam). The results showed that plant height traits, panicle length, one-thousand grain weight, panicle weight, grain weight in panicle, grain yield, protein percentage, sugar, starch and seed fat were affected by irrigation cut at different stages of growth. There was also a significant difference between different cultivars based on height traits, number of claws per plant and length of panicle. The results of the mean comparison showed that water deficit tension reduced grain yield and in terms of water cut-off tension before pollination compared to control caused 63.95 percent of yield loss and in terms of irrigation cut in milking stage compared to control, 34.4 percent of yield loss. While by cutting off the water in the paste stage, the yield increased by 2.2 percent compared to the control. In general, the highest grain yield, one thousand grain weight and panicle weight were obtained in Kimia cultivar, which could represent a more tolerant cultivar to water deficit tension.

In order to investigate the morpho-physiological responses of purslane plant to humic acid under Nickle stress a split plot experiment based on a completely randomized design with two factors and three replications were carried out in the greenhouse. The factors were nickel concentrations with four levels (0, 0.2, 0.4 and 0.6 mM) as the main plots and four levels of humic acid concentrations (0, 200, 400 and 600 mg/L) as sub-main plots. The results showed that different nickel and humic acid concentrations had significant effects on most of morpho-physiological traits such as; root length, MDA, SOD, CAT chlorophyll and carotenoid contents. By increasing nickel levels, the growth indices such as shoot and root length, fresh and dry weight, chlorophyll, a, total chlorophyll and the amount of carotenoid decreased, while by increasing the nickel levels the proline content, MDA and CAT decreased. By increasing humic acid level, the proline content and the activity of CAT increased, while the amount of MDA and SOD enzymes decreased. The highest yield and chlorophyll and carotenoid contents was obtained at 0.4 mM nickel and 600 mg/L humic acid. However, it can be concluded that applying the humic acid can be a suitable procedure to reduce the harmful effects of nickel stress and improving in physiological and biochemical parameters and plant tolerance to nickel stress in Portulaca oleracea.

The increase of organic and inorganic compounds in the river basin of the south coastal area of the Caspian Sea has been exacerbated by intensification of the Eutrophication process. In order to provide some useful data for planning of coastal management, the trophy of the chlorophyll a, total phosphorus and total nitrogen were determined. The result of measuring three limnologic parameters (chlorophyll a, total phosphorus and total nitrogen) for a period of 11 months, were entered into the geographic information system during the spring of 2013 to February 2014. By determining the position of ten stations in south coast of the Caspian Sea, in Gilan province, from Khosk-Rood to Astara, their trophy status in terms of chlorophyll a, total phosphate, total nitrogen, as well as TSI index were determined. Based on the results of this study, among the three effective factors of trophic in the studied areas, in winter, the highest correlation was found between total phosphorus and total nitrogen of 47%. The annual survey showed a correlation between phosphorus and total nitrogen of 87%, followed by correlation between chlorophyll a and nitrogen of 56%. The results showed that, 39 and 61 percent of south coastal areas in Gilan province were oligotrophic and mesotrophic, respectively. The normal curvecomparison of total phosphate based on OECD standards, indicated a trend in coastal change from oligotrophic to mesotrophic, which can be a threat to the region

This experiment explored the impact of seasonal changes on the activity of photosynthetic pigments (i.e., Chlorophyll a, Chlorophyll b, & Carotenoids) and proline on Haloduleuninervis sea grass. The results indicated a decrease in Chlorophyll a during the spring and summer and a decrease in Chlorophyll b and Caroteniods during the fall and winter. Furthermore, proline measurement revealed that its amount in root was less than leaf and that the maximum amount of proline in leaf and root belonged to the spring and summer. The ANOVA results showed a significant difference at p

Effect of salinity, ammonium and cytokinin on biomass and the content of agar in Gracilaria corticata algae were evaluated in a period of 42 days under laboratory condition. The alga G. corticata was sampled from coasts of Bostaneh port in Hormozgan province in June 2009. The algae were raised in aquariums 40.30.60 cm with 20 liter capacity, by suspension method in 3 replicates under light intensity of 3300 lux and 25oC temperature condition. The algae were cultured under salinities 25, 35 and 45 PPT, ammonium concentrations (0.00, 0.001 and 0.002 gram per liter) and cytokinin (0.01, 0.001 and 0.0001 mol). The algae were harvested once a week and weighted. At 6 weeks of experiments, the algae were collected, dried and weighed. The highest biomass of G. corticata was at 25 PSU (4.58 grams), 0.01 mol cytokinin (14.88 gr) and 0.002 mol ammonium (26.34 gr). Maximum level of agar was observed in ammonium concentration of 0.002 equal to 32.56 percent. The results of this work showed that G. corticata is one of the commercial algae in the world and this alga needs to be cultured near estuaries with high amount of ammonium.

In this work, the batch removal of Ni ions from aqueous solution and wastewater using marine brown alga Sargassum was investigated. Activated carbon, prepared from Sargassum by acid decomposition, was also used for the removal of Ni from aqueous solution and wastewater. The effects of pH, biosorption time, adsorbent dose, metal ions concentration were considered. The most effective pH was found to be 5.0. The maximum uptake rates for nickel with initial concentrations of 30, 50 and 70 mg/L were obtained to be 97.8% , 84.53% and 60.34% respectively at pH=5. The equilibrium adsorption data were fitted to isotherm models. The adsorption followed second order kinetic. This study shows the application of activated carbon as valuable material for the removal of Ni from aqueous solution and wastewater

In this research, the Halodule uninervis sea grass was collected in the tidal area of Golshahr (Bandarabaas-Iran) in maximum period of ebb in summer-autumn- winter 88 to spring 89. The physiological analysis of Halodule uninervis was performed three times by measuring Photosynthetic pigments (Chlorophylls a, b and Carotenoids) and the amount of Prolinewas also investigated. The results indicated that the minimum amount of Chlorophyll a was found in spring (1/19 ± 0/002 mg/g) and the minimum amount of Chlorophyll b (0/68 ± 0/003 and 0.68 ± 0/003 mg/g) and Carotenoids (1/25 ± 0/002 and 1/26 ± 0.002 mg/g) was found in autumn and winter respectively. The Proline measurement revealed that the amount of Proline in roots was less in comparison to the leaves and the minimum amount of Proline found in roots was in spring (0/07 ±0/006 mg/g) and summer ( 0/08 ± 0.004 mg/g).

The green alge Gracilaria salicornia was collected from coasts of Gheshm Island in Persian Gulf in September 2010.The effect of temperature, photoperiod and irradiance on growth of Gracilaria salicornia were carried out over 6 weeks under laboratory conditions. For each treatment, the algae were inoculated into 20 litre water with diameters of 60×30×40 cm. The suspension method used for culture .All treatments (tanks) were carried out in triplicates. The treatments were temperatures (20, 25 and 30oC), photoperiods (12:12, 14:12 and 16:8, light: dark, respectively) and photon irradiances (24, 66 and 94 photons m-2 S-1). The length, width and weight of the thalli were measured on 7, 14, 21, 28, 35 and 42 days. The results of this study showed significant differences on growth of G.salicornia between treatments (P<0.05). Maximum relative growth rate was obtained from 12:12 photoperiod with 2.46 %.

Sargassum is one of the main sources of alginate, the substance with many commercial uses. The species Sargassum boveanum is an edible algae and study of effect of environmental factors on its growth is a step towards is culture. Therefore, growth of Sargassum boveanum under various temperature, irradiance and photoperiod was studied over 6 weeks under laboratory condition. The macroalgae was collected from coasts of Lengeh in June 2011. For each treatment, the algae were inoculated into 20 liters of water aquariums with diameters of 60×30×40 cm. The suspension method used for culture of algae. .The culture conducted at 4700 lux for irradiance, 25Co for temperature ,35PPT for salinity and 12:12 hour (light: dark) photoperiod. The treatments were: temperature (15, 20 and 25oC), photoperiod (12:12, 14:10 and 16:8, light: dark, respectively) and photon irradiances (4700, 5700, 6700 lux). All treatments (tanks) were carried out in triplicates. The length and weight of the thalli were measured on 7, 14, 21, 28, 35 and 42 days. The results of this study showed significant differences on growth of S. boveanum between treatments. Maximum relative growth rate was obtained at 12:12 hour photoperiod (% 4/32), 25Co (% 2.68) and 4700 lux (% 4.32) that proved to be suitable for indoor culture. We recommend spring as the best season for mariculture this alga.

Microalgal growth can be restricted due to low levels of nutrients in the environment. Moreover, there can be changes in their biochemical content. Some microalgae are used for feeding various animal breeds. In spring of the 1390 a study was conducted at the Islamis Azad University of North Tehran Branch, Tetraselmis suecica was grown in f2 Guillard culture in various concentrations of nitrate (6.12 (low), 12.25 (standard), and 24.71 (high) mgL 1) and the effect of different concentrations of nitrate on the amount of protein, chlorophyll, and dried weight of algae Tetraselmis suecica was evaluated. Results showed that increasing the amount of nitrate significantly increased the protein content of algae (p < 0.05). The amount of protein by the 5th day of culture in high concentration of nitrate was at 5.8%, which increased to 10.7% by the 9th day. However, the amount of protein in the 9th day of culture for standard and low nitrate concentrations did not exceed 5.8% and 5.1% respectively. Chlorophyll a decreased significantly (p < 0.05) as a result of decreasing the available nitrate levels for algal cells. By the 9th day, the dried weight of cells grown in low nitrate concentration was measured at 0.18 mgL-1, and in high concentration of nitrate at 0.156 mgL-1.

Effects of salinity, ammonium and cytokinin were evaluated on  Gracilaria corticata algae in a period of 42 days under vitro condition . G .corticata was sampled from coasts of Bandar Bostaneh in Hormozgan Province in June 2009.The algae were raised in aquariums, 40*30*60 cm with 20 liter capacity, and using suspension method in 3 replicates. Light intensity to grow was 3300 lux and temperature was 35 degree centigrade. The treatments include 25ppt (salinity of brakishwater), 35ppt (marine), ammonium (0.001& 0.002 mol.) and cytokinin (0.01, 0.001& 0.0001mol.). Sampels were harvested once a week. Length, weight and relative growth rate were measured. Result showed that, effects of environmental factors of salinity , ammonium and cytokinin on G.corticata were significant(P<0.05).The growth of G.corticata in different levels of concentration of cytokinin and salinity and ammonium in different days showed significant differences and its maximum level was observed in ammonium concentration of 0.002 mol. with 8.02 percent.

In this research, identification and biomass of macroalgae in Jofreh, Naftkesh, Daneshjo, Lian sights in Bushehr Province in winter 1388 (2010) at low, mid and high intertidal zone have been studied. Sampling was done randomly with 0.5 m2 quadrate. Totally 9 genera of green, red and brown macro algae were recognized. Maximum and minimum biomass of algae belonged to brown and green algae with 2166/7and 687g/m2, respectively. The green algae  Codium, sp., Chaetomorpha, sp. , Chatomotpha gracilis and the red algae   Hypnea sp., Gracillaria, sp., Laurencia,sp. , Gracillara corticata, Laurencia papillosa and Laurencia obtuse , also 6 brown algae including Sargassum sp., Padina sp., Colpomenia sp. , Cystoseria sp. ,Colpomenia sinuosa and Cystoseria fimbriata, were recognized. Key words:

Aquatic environments are often exposed to heavy metals, this can affect aquatic organisms. The effect of Cu 2+ on cell density and chla content of  S.obliquus was studied. The algae were grown for 5 days at temperature of 2± 23  ˚c and light intensity of 300 lux on z8 medium .Copper  treatment was carried out at a concentration of 0 (control) ,2,4,,6 and 8 mgl-1. Cell counting was performed at 0,24,48,72 and 96 hours using heamocytometer and amount of chla was determined at the same hours. There was a significant difference between time and treatments (p< 0.05). The difference of cell density was significant between control and metal concentrations, 2,4 mgl-1 with 6,8 mgl-1. In control groups, the cell density and chla content were increased with time. On the other hand, the content of chla and cell number reduced with Cu2+ . The concentration of Cu2+ from 2 to 8 mgl-1 inhibited cell density from 72.09% ( 2mg.l-1 , 96 h) to 92.33% ( 8mgl-1,96 h), respectively. In the Cu2+ treatments the death of algal biomass was observed in 24 h, but there was an increase in cell numbers of S.obliquus in control and the algae were still on exponential phase at 96 h.