EDTA (Etilendiamintetraasetat)' nın 10nM Fe(III) konsantrasyonunda Thalassiosira weissflogii (Bacillariophyta)' nın büyümesine etkileri

Demir (Fe) biyolojik olaylarda görev yapan önemli bir eser metaldir ve pek çok organizma için hayatidir. Fe'in biyolojik olaylarda hala tam olarak bilinmeyen işlevleri, sudaki kullanılabilir formları ve alımını etkileyen faktörlerin belirlenmesi konularına katkıda bulunmak amacıyla yürütülen çalışmada, 10 nM demir (Fe) içeren modifiye F/2 ortamında, suni ligand EDTA (Ethylenediaminetetraacetate) (100pM) nın, Thalassiosira weissflogifnm büyümesine etkileri araştırılmıştır. Denemenin yürütüldüğü ortamda, 18 ± 2 °C sıcaklık ve 80|jmol m~2 s1 aydınlanma şiddeti sürekli olacak şekilde sağlanmıştır. Denemede kullanılan deniz suyu, makro besleyiciler ve EDTA, Chelex-100 reçinesinden geçirilmiş, kullanılan bütün malzemeler ise asit ile yıkanarak eser metallerinden arındırılmıştır. Denemenin sonunda, EDTA nın, T. weissflogii kültürlerinde, hücre yoğunluğu, klorofil-a miktarı, büyüme hızı ve büyümeye paralel olarak artan pH değerlerini etkilemediği (p>0.05) saptanırken hücresel Fe miktarları arasında farklılık olduğu (p

The effects of EDTA (Ethylenediaminetetraacetate) on the growth of thalassiosira weissflogii (Bacillariophyta) in 10nM Fe(III) concentration

Being active in a number of biological events, iron (Fe) is essential trace metal, which is vital for a great many organisms. In an effort to find out a biological approach to the functions of Fe, which are not yet fully understood, and its available marine forms as well as to help determine the factors affecting Fe uptake, the effects of artificial ligand EDTA (Ethylenediaminetetraacetate) (100jjM) on the growth of Thalassiosira weissflogii were studied in modified F/2 medium consisting of 10nM iron. An ambient temperature of 18± 2 °C and lighting intensity of 80|jmol m2 s-1 were provided during the experiment. Sea water used macro nutrients and EDTA were let through Chelex-100 resin while all other items were freed from any trace metals in acid bath. Acording to the results, it was found that in T.weissflogii culture, EDTA didn't have any effect on cell number, the number of chl-a, growth rate and the pH values which increased proportional to the growth (p>0.05). It was also appeared to be a difference among cell Fe quota (p

PDF

___

Boyd, C.E. 1979. Water Quality in Warmwater Fish Ponds. Auburn University Agricultural Experiment Station.
Coale, K.H., Johnson, K.S., Fitzwater, S.E., Gordon, R.M., Tanner, S., Chavez, F.P., Ferioli, L, Sakamoto, C, Rogers, P., Millero, F., Steinberg, P., Nightingale, P., Cooper, D., Cochin, W.P., Landry, M. R., Constantinou, J., Rollwagen, G., Traswina, A., Kuela., R., 1996. A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean. Nature, 383; 495-501.
Anderson, M.A. and Morel, F.M., 1982. The influence of aqueous iron chemistry on the uptaka of iron by the coastal diatom Thalassiosira weissflogii. Limnol. Oceanogr., 27:789-813.
Geringa, L.J.A., De Baar, H.J.W., Timmermans., 2000. A comparison of iron limitation of phytoplankton in natural aceanic waters and laboratory media conditioned with EDTA. Marine Chemistry., 68; 335-346.
Guillard, R.R.L., 1973. Division Rates in Handbook of Phycological methods (J. R. ETEIN editör). Culture Methods and Growth Measurements, Chambridge Universty Press, Chambridge, pp.289-311.
Harrison, G.J, and Morel, F.M.M., 1986. Response of marine diatom Thalassiosira weissflogii to iron stress. Limnol. Oceanogr., Vol.31, pp.989-997.
Martin, J.H., Coale, K.H, Johnson, K.S., Fitzwater, S.E., Gordon, R.M., Tanner, S.J., Hunter, C.N., Eldor, V.A., Nowicki, J.L., Coley, T.L., Barber, R.T., Lindey, S., Watson, A.J., Van Scoy, K., Law, C.S., Liddicoat, M.I., Ling, R., Station, T., Stockel, J., Collins, C, Anderson, A., Bidigare, R., Ondrusek, M., Latasa, M., Millero, F. J., Lee, K, Yao, W, Zhang, J.Z., Fredierich, G., Sakamoto, C, Chavez, F., Buck, K., Kolber, Z., Green, R., Fallowski, P., Chisholm, S.W., Hoge, F., Swift, R., Yangel, J., Turner, S., Nightingale, P., Hatton, A., Liss, P., TindaleE, N.W., 1994. Testing the iron hypothesis in ecosystems of the equatorial pacific Ocean. Nature, 359:123-129.
Mckay, R.M.L., Geider, R.J and Lacroche, J.,1997. Physiological and Biochemical Response of the Photosynthetic Apparatus of Two marine Diatoms to Fe stress. Plant Physiol., 114; 615-622.
Martin, J.L., Gordon. R.M., Fitzwater, S.E., Broenkow, W.W, 1989. Deep-Sea Research. Part A. Oceanographic Research, Page:36
Öztürk, M. 2002;2003;2004. Doğal Bilimler ve Teknoloji Fakültesi, TBS. Norwec Bilim ve Teknoloji Üniversitesi. Trondheim, NO-7491.
Shkolnik, M.Y., 1984. Trace elements in plants. Develop. Crop Sci. V. 6. Elsevier.
Sunda, W.G., Huntsman, S.A., 1991. Low iron requirement for growth in oceanic phytoplankton. Nature, 351:55-57.
Sunda, W.G., Huntsman, S.A., 1995. Iron uptake and growth limitation in oceanic and coastal phytoplankton. Mar. Chem., 50:189-206.
Schmidt, M.A. and Hutchins, D.A., 1999. Size-fractionated biological Fe and uptake along a coastal to offshore transect in the NE Pacific. Deep-Sea Res. 11,46/12, in press.
Van Den Hoek, C, Mann, D.G., Jahs, H.M., 1995. Algae an Introduction to phycology. Cambridge University Press.133,219:614.