Authors:Alexander Alyabyev, Ireana Andreyeva and Guzel Rachimova
respiration of these microalgae have a close resemblance with those in plants and thus they are valid models for them.
As is known, infringement of an ionic homeostasis as in a case of salting, and any ion stress, including changes of proton
Authors:V.M. Nascimento, K.M. Nascimento and G.G. Fonseca
Microalgae are unicellular organisms of rapid growth. They are found in marine environment, freshwater, and soil. They have the potential to reduce emerging environmental problems, e.g. greenhouse effect and water pollution ( H arun et al., 2010
Marine micro-algae (Nannochloropsis sp., Phaeodactylum sp., etc.) wereobtained from the Pacific Ocean off Iwate Prefecture, Japan, and culturedpurely in nutritive seawater, PES and artificial seawater, ASP7 as a culturesolution. The algae in 5 ml of the culture solution was collected on a polycarbonatefilm (pore size : 1.0 µm) by suction filtration. The algae on the filmwas subjected to PIXE analysis. A 2.9 MeV proton beam bombarded it at 50 nAfor 15 minutes. Induced X-ray was measured by Si(Li) detector. Concentrationsof Na, Mg, Al, Si, P, S, Cl, K, Ca, Cr, Mn, Fe, Cu, Zn and Sr were determinedsimultaneously. PIXE can used for multi-element analysis of a sample below1 mg, so the culture size for algae was 10–250 ml and every apparatuswas small and of low cost. Nannochloropsis sp. was given a different culturesolution (PES) including Zn2+ from 0.050 to 1.0 mg/l and incubatedat 22 °C, 2000 lux for 10 hours. Zn in Nannochloropsis sp. increased inproportion to the Zn2+ concentration in the culture solution. Theconcentration factor was given as 1600 500 (dry weight base). It was shownthat PIXE was a powerful tool for multi-element analysis of micro organismsand the measurement of bioaccumulation.
Ördög, V., Stirk, W. A., van Staden, J., Novák, O., Strnad, M. (2004): Endogenous cytokinin in three genera of microalgae from the Chlorophyta. J. Phycol. , 40 , 88-95.
Endogenous cytokinin in three genera of microalgae from
At first, a natural widespread mass growth of Zygnema stellinum was recorded in El-Hikstep new city (Egypt). The mechanical, physical and chemical characters of the wet soil in El-Hikstep new city where filaments of Zygnema were collected; the natural city soil where there is no growth and soil from ditches after the death of the filamentous growth were studied and analysed. The current study revealed that pH, E.C., MgSO4 and NaCl, available P and N were the most controlling factors those enhance the green algal mats growth of Zygnema stellinum in this site. The physico-chemical analysis of soil sample after the death of Zygnema was characterised by a reduction in the values of pH, E.C., change in soil texture from sand in city soil to loamy-sand for two other soil samples. These were associated with increase in the values of organic matter, organic carbon, phosphorus, nitrogen and Fe comparing with physico-chemical analysis of the city soil sample. These may emphasise that the growth and death of green algal mats of Zygnema in soil probably have reclaimative properties in soil. Meanwhile, cultivation test revealed successfully growth of Zygnema stellinum in city soil extract medium followed by the city soil extract nutritive media. Whereas the growth of Zygnema stellinum in Beijerinck and Allen media doesn’t well.