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Growth and Some Metabolic Features of Cyanobacterium Fischerella Sp. FS18 in Different Combined Nitrogen Sources.
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نویسنده
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Soltani N. ,Khavari-Nejad R. A. ,Tabatabaei Yazdi M. ,Shokravi S.
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منبع
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journal of sciences islamic republic of iran - 2007 - دوره : 18 - شماره : 2 - صفحه:123 -128
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چکیده
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In the present research the growth and metabolism of cyanobacteriumfischerella sp. fs18, isolated from rice fields of gillan province (iran), were evaluated in different nitrogen sources. this strain is a good candidate as biological fertilizer due to high efficiency to n2 fixation. in this way, cells in logarithmic phase of stock were treated with different nitrogen sources (n-free, 1 & 2 mm nh4 + and 5 and 10 mm no3-). results indicated that maximum growth rate belonged to no3- treatment. dry weights of fischerella sp. fs18 in n-free medium and ammonium were in decreasing order of preference; and nh4 + 2 mmwas drastically toxic for this strain. the highest chlorophyll concentration was detected in n-free medium. no3 - 5 mm and nh4 + 2 mm had the lower contents of this pigment. photosynthesis rate varied the same as chlorophyll. phycocyanin and phycoerythrin had the highest rate in nitrate. the highest light-saturated photosynthetic rate and also steepest initial slope clearly belonged to nitrogen free-medium. all types of combined nitrogen sources had inhibitory effect on nitrogenase activity, regardless of the concentrations used. our results indicated that fischerella sp. fs18 is a potent diazotrophic species with increasing growth in the presence of nitrate; and ammonium 2mm seems to be toxic for it.
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کلیدواژه
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Ammonium; Cyanobacteria; Fischerella sp.; Nitrate; Nitrogenase; Photosynthesis;Photosynthetic pigments.
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آدرس
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ACECR, Research Institute of Applied Science., Department of Plant Ecology and Systematic , Iran., University for Teachers Education., Faculty of Science , Department of Biology , Iran., tehran university of medical sciences tums, Faculty of Pharmacy , Department of Pharmaceutical Biotechnology , ایران, Islamic Azad University, Branch Gorgan., Faculty of Science , Department of Biology , Iran.
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پست الکترونیکی
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soltani6@yahoo.com
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Authors
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