IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
EFFECT OF FE SUPPEMENTATION DURING THE DEVELOPMENT OF THE ANTARCTIC DIATOM FRAGILARIA SP
Autor/es:
PUNTARULO S,; ROBELLO E
Lugar:
Buenos Aires
Reunión:
Congreso; Reunión Conjunta de las Sociedades de Biociencias; 2017
Institución organizadora:
SAIB
Resumen:
The aim of this work was to evaluate the effect of moderate Fe concentrations on the nitrosative metabolism in cultures of the diatom Fragilaria sp (from natural populations of the Antarctica) grown in f-2 media supplemented with either 0.3 (control) or 50 µMFe-EDTA (1:1). The growth was evaluated, over 15-20 days at 4ºC under 12 h light-dark cycle, by spectrophotometry and by cellular counting, the total intracellular Fe content by spectrophotometry, labile iron pool (LIP) by spectrofluorometry, nitrite-dependent nitric oxide (NO) generation by Electro Paramagnetic Resonance, and nitration of total protein by Western Blot. The supplementation with 50 µM Fe increased the total Fe content by 22-fold (p≤0.01) and the LIP by 2.3-fold (p≤0.1), as compared to values in control cultures in exponential phase of development (Exp). However, Fe supplementation from 100 to 500 µM Fe increased linearly the LIP content (m= 0,0155% R2 = 0.835) in Exp. The growth rate of the cultures supplemented with 50 µM Fe in Exp was increased by 3-fold, as compared to growth in control cultures (p≤0.05). The total cellular protein nitration in cultures exposed to 50 µM Fe in lag phase of development (Lag) was slightly increased (1.3-fold) respect to values in control cultures (p≤0.1). Supplementation with 50 µM Fe produced a significant reduction (7.9-fold) in the nitrite-dependent NO generation rate in Lag, as compared to the values in control cultures (p≤0.01). These results suggested that increases in Fe in the culture, as those seen in the natural habitat, could be appropriately control by endogenous mechanisms avoiding drastic increases in LIP. However, presumable due to the Fe capacity of NO chelation, associated to Fe-dependent ability of catalyzing reactive species generation, the exposure to an Fe excess in the medium lead to alterations in the nitrosative metabolism in the cell in the lag phase of development when antioxidant pathways are still not fully operative.