Publication Date: 2006
World Journal of Microbiology and Biotechnology (09593993)22(9)pp. 1003-1006
Three strains of Dunaliella salina (I, G and A) were cultivated under the climatic conditions of Iran, in open ponds to compare the β-carotene production and the specific rate of growth. The experiments were accomplished in two separate stages. In the first stage, the cells were grown in ponds on nutrient-rich medium containing 2 M NaCl to obtain the necessary biomass. In the second stage, cells were stressed on nutrient-poor medium containing 2.5 M NaCl for β-carotene induction. The results showed that the specific growth rate of strain I was the highest during the first stage, whereas during the second stage, the growth rates of three strains were approximately the same. The overall results indicated that strain G had the highest potential for β-carotene accumulation of the strains tested and hence it was concluded that this strain is more suitable for outdoor cultivation under the climatic conditions of Iran than the other two. © Springer 2006.
Publication Date: 2006
Pakistan Journal of Biological Sciences (18125735)9(8)pp. 1492-1496
Four strains of Dunaliella salina (I, G1, A and MUR8) were cultivated under the three salinity regimes (1, 2 and 3 M NaCl) to examine the effect of salinity on the β-carotene synthesis per cell and to compare the β-carotene production per culture volume and the rate of growth. During the 30 days of the experiments the batch cultures maintained in the 300 flasks containing 100 of Johnson's medium under the low irradiance (100 μmol photon m-2 s-1) with a 12/8 h light/dark regime and a continuous shaking. The results showed that the inductive effect of salinity on β-carotene accumulation per cell was strain dependent and when the values for the strains IR-1 and Gh-U were slightly higher at 3 M NaCl compare to lower salinities, there were no direct relationships between the concentrations of salt and the β-carotene contents per cell in other two strains (MUR-8 and Au-W). On the other hand, increase the salinity result in serious decreasing in the cell number and the β-carotene content per culture volume of all strains during the experiment. The highest β-carotene content per (14.2 mg L-1) was obtained at 1 M NaCl in the suspension culture of the strain Au-W. © 2006 Asian Network for Scientific Information.
Esmaeili, F.,
Tiraihi, Taki,
Movahedin, Mansoureh,
Mowla j., S.J. Publication Date: 2006
Rejuvenation Research (15491684)(4)
The antiaging effect of selegiline was reported by several investigators; therefore, there is a growing interest in the potential use of stern cell therapy in aging. In this investigation, selegiline was used to induce neuronal differentiation in undifferentiated pluripotent embryonic stem cells (ESCs). The results show that selegiline can induce neuronal phenotype associated with neurotrophic factor expression. Morphologic and immunohistochemical techniques were used to evaluate the differentiation of the CCE cells, Cresyl violet for the morphologic study, anti-synaptophysin and antityrosine hydroxylase antibodies for characterizing the neuronal phenotype of ESCs, and RT-PCR to study the neurotrophins. The results showed that selegiline can induce dose-dependent ESC differentiation into neurons. Moreover, selegiline can induce neurotrophin expression. This study suggests the potential use of combined selegiline and stem cell therapy to improve deficits in neurodegenerative diseases in aging. © Mary Ann Liebert, Inc.
Publication Date: 2006
Pakistan Journal of Biological Sciences (18125735)9(11)pp. 2048-2054
Under circumstances where electron transport is restricted, such under low temperature condition, oxidative stress may occur even at optimal or low-light intensities. Short-term-effects of light intensities (20 or 100 μmol m -2 sec-1), on the levels of 6 enzymatic, two nonenzymatic antioxidants, chl a, chl b, total carotenoid and β-carotene, on the antioxidant response of Dunaliella salina under cold temperature (13°C) were quantified after 24 h stress treatments. The activity of superoxide dismutase (SOD) increased, under 13°C/100 μmol m-2 sec-1, whereas ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), superoxide dismutase and pyrogallol peroxidase activities were induced under 13°C/20 μmol m-2 sec-1. The cells exhibited an increase in reduced ascorbate and reduced glutathione (GSH) coincident with a marked increase in oxidized glutathione (GSSG), at 13°C/100 μmol m -2 sec-1. There were no marked changes in ascorbate or glutathione pools at 13°C/20 μmol m-2 sec-1, which are similar to those at 28°C/100 μmol m-2 sec-1. Chlorophylls and carotenoids reduction were also observed under chilling treatments, which were more reduced by the higher light intensity (13°C/100 μmol m-2 sec-1). The results of present study indicated various antioxidants responds to different combinations of chilling and low light intensities, in D. salina. These responses are very sensitive to small increase in the light intensity. © 2006 Asian Network for Scientific Information.
