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The phenomenon of cyanobacterial bloom, among other things, is chronic and periodic pollution, which is mainly caused by phosphorus and nitrogen, as well as high temperatures and direct sunlight. To carry out this experiment, in order to obtain blooming cyanobacteria in the warm water pond fish, water samples were taken from 5 farms and after purification, mass culture of 4 species of cyanobacteria that had the highest density was prepared. Then kaolin with a concentration of 0.5 g/liter and separately with two sizes of 50 and 100 micrometers was added to the pure culture of any cyanobacteria species using a 1-meter column. The amount of reduction of cyanobacteria was checked by counting by Neubauer chamber at 0, 3, 9 and 24 hours after adding to it. The results showed the decrease in the number of cyanobacteria Chroococcus sp. For kaolin with two sizes of 100 and 50 micrometers, it was 24.4 and 39%, respectively. This rate was 25.8 and 15.5% for the cyanobacterium Gloeocapsa sp. Also, for cyanobacterium Oscillatoria sp., 23.5 and 35.3% were calculated and finally for cyanobacterium Microcystis sp., 29.4 and 33.3% were calculated. The results of this research showed that the separate use of two sizes of kaolin, 100 and 50 micrometers, is effective for the immediate control of cyanobacterial bloom, and also, comparing the two sizes of kaolin, kaolinite with the size of 50 micrometers had better operation. [ABSTRACT FROM AUTHOR]

Heavy metals such as mercury (Hg) can cause disturbances in the metabolic and phycoremediation activities of microalgae. γ-aminobutyric acid or GABA is a non-protein amino acid and has a signaling role that can regulate the homeostasis of reactive oxygen species (ROS) under environmental stress. In this research, the effect of exogenous GABA on the physiological responses of blue-green algae (cyanobacterium) Spirulina platensis under mercury stress was investigated. HgCl2 in 4 and 8 μM, and GABA in 2 and 4 mM, individually and as a combined treatment, were applied to the microalgal cell suspensions for 48 hours. Then, the indices; dry weight, chlorophyll a, carotenoid, phycobilins, phenol, carbohydrate, protein, malondialdehyde, and polyphenol oxidase and peroxidase activities were evaluated. HgCl2 treatment (individually) decreased dry weight, chlorophyll a, carotenoid, phycoerythrin, phenol, carbohydrate and protein compared to those in control and increased the level of lipid peroxidation and the activities of polyphenol oxidase and peroxidase enzymes. Single treatment of GABA increased dry weight, phycobilin, phenol, malondialdehyde, protein and enzyme activity. But the combined treatments (GABA + HgCl2) improved most of the physiological indices. HgCl2 treatment in one or both concentrations caused a negative effect on the physiological indicators of Spirulina platensis and decreased metabolites such as phenol and proteins, but GABA treatment in most cases reduced the negative effects of mercury and improved the indices. According to the literature, Hg toxicity can be caused by disrupting the biosynthesis of photosynthetic pigments and the activity of enzymes and the occurrence of oxidative stress. While, exogenous GABA can improve the metabolic and physiological cell condition as a signaling molecule through the occurrence of some intracellular events. [ABSTRACT FROM AUTHOR]

The blue green algae as photosynthetic organisms have a main effect on life and productivity of the aquatic ecosystems. Intensive and longtime studies on identification, distribution, and diversity of Cyanophyta have to be a crucial task in the Caspian Sea. Four transects were determined parallel to the Sabzehrud River, the Lavij River, the Noor River, and the Faculty of Marine Sciences of Tarbiat Modares University from 2014 to 2015. Samples were seasonally collected from three stations in each transect by a plankton net with a mesh size of 55 and the Ruthner's bathometer. Standard hydrobiological and phycology approaches were used for identification and counting abundance of Cyanophyta. The most number of Cyanophyta was observed 1.06 × 106 cells per liter at the station of A1 during summer. Genera such as Chroococcus, Gloeocapsa, Merismopedia, Microcystis belonged to unicellular taxa and Anabaena, Anabaenopsis, Nostoc, Oscillatoria, Phormidium were identified as multicellular genera. At the most stations, Anabaenopsis nadsonii was found as the most encountered species. Overall, Cyanophyta abundance was significantly different among stations in all investigated seasons. The blue green species also did not have same frequency distribution inside of the each transect (Test Chi-Square, P

Environmental pollution by heavy metals is one of the main problems in the environment. Biosorption, is inactivated or live and dead biomass is used for the removal of heavy metals. In this study, a micro alga (Cyanobacteria) Spirulina platensis was used as adsorbents for the remediation of copperfrom aqueous solution.The purpose of this research is to study the possibility or impossibility of copper heavy metal removal by cyanobacteria S. platensis under different environmental conditions. Bisorption of Copper under different conditions, including different concentrations of copper (10, 50, 100, 200 mg /L), pH (3, 4, 5, 6), time (30, 60, 120, 360 min) and the concentration of biomass non-living (0.5, 1, 1.5, 2 g / L) were studied. Finally, toincrease the efficiency of cyanobacteria were determined absorb theoptimal conditions using the Taguchi method. The optimization process of absorption, the bestamount of each of the parameters pH 5, and the weight of the algae S. platensis 0.5 g/L, 200mg/L for metal concentration and the time required was120 minutes. The results showed that the S. Platensisbiomassis suitable for economic development and efficient structures for the removal of heavy metals from aqueous solutions.

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. [ABSTRACT FROM AUTHOR]

The present study was aimed to identify thermophilic cyanobacterial of Chah-ahmad hot springs located in Hormozgan province. Sampling was done based on water resource condition, Water physicochemical analysis was performed due to their dramatic effects on species distribution. Thermophilic samples collected at different temperature gradients were fixed in 4% formaldehyde to minimize changes in phytoplankton. The taxonomic determination was carried out using artificial keys presented in some valid publications. Semi-permanent slides of each isolate were prepared and morphometric study is done using light microscopy. The vegetative and reproductive characters such as shape, color and size of the cell, colony, thallus and trichomes, shape, size and color of vegetative cells, apical cell shape, presence of sheaths and some other morphological were used in the taxonomic determination. Results showed the highest level of diversity was achieved at lower temperatures. Jaaginema angustissimum, Jaaginema pseudogeminatum and Jaaginema metaphyticum were present in all temperature gradients and well adapted to temperature gradients. CCA analysis was done in order to explore the relationship between the species composition in individual spring and physic-chemical parameters as environmental variables. According to the result indicated species are well separated along some parameter such pH, Do, temperature, Ca, Na, K, No3, Po4, So4.

Present study was aimed to identify thermophilic cyanobacterial of three hot spring included, Hajiabad, Khorgoo and Geno located in central part of Hormozgan province. Sampling was done based on water resource condition physicochemical analysis of the water due to a dramatic effect on species distribution was performed, samples collected at different temperature gradients and were divided into two part, one part was fixed in 4% formaldehyde due to minimize quantitative and qualitative changes in phytoplankton and another were kept in a refrigerator for preparing and isolating pure cultures. Taxonomic determination was carried out by morphological characters such as shape, color and size of the cell, colony, thallus and trichome width and length of them shape, size and color of vegetative cells and …, based on artificial valid keys by prepared semi-permanent slides. Results showed these three hot springs have temperature ranging from 33 to 45°C, high distribution of blue-green algae, occurring in Hajiabad spring because of low temperature, in apposite Khoorgoo spring had lowest species distribution because of unfavorable environmental conditions. In each spring also achieved the highest level of diversity at lower temperatures. The species Jaaginema angustissimum, Jaaginema pseudogeminatum, and Jaaginema metaphyticum in all springs and all temperature gradients were present.