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Showing 3 results for Nannochloropsis Oculata
Masoumeh Amouzad Khalili, Abdolmohammad Abedian Kenari, Masoud Rezaei,
Volume 6, Issue 1 (6-2017)
Abstract
The effect of vitamins C and E in enhancing the shelf life of the algal paste during 12 weeks cold storage (4°C) was assessed. The microalga, Nannochloropsis oculata, was grown in Conway media under 24ºC temperature, 25ppt salinity, and continuous light intensity of 1000- 2000 lux with) and harvested at the logarithmic phase by cream separator centrifugation at 12000 rpm in the form of paste. The algal cell viability was determined by Evans blue dye. The algal paste samples were treated with different vitamin treatments, including: vitamin C and E (0.1%w/w), and an equal proportions of mixed vitamin E and C, and then stored in refrigerator for two months. The results showed that the 95% cell viability of vitamin C treated paste was significantly higher than the control group (p>0.05). FFA and pH in vitamin C treated group was lower than the control treatment. The comparsion of between different treatments during the storage period indicating that it contains vit E had a slower increase than the other treatments in during the storage the time. Overall, it was demonstrated that vitamins functioned as suitable preservatives for the microalgal paste in cold storage (4 °C).
Volume 11, Issue 2 (6-2020)
Abstract
Objectives: In this study, the effect of different concentrations (1-50 mg/L) of colloidal Ag-NPs investigated on the growth, fatty acids profile and biodiesel indices of N. oculata, after estimating EC50 (20.88 mg/L).
Materials and methods: In this research, N. oculata was selected owing to fast growth and its ability to synthesize lipids for biodiesel production. This microalga exposed to colloidal silver nanoparticles under marine conditions for 72 h. The optical density (OD) and fatty acid profiles were investigated using spectrophotometric analysis and gas chromatography, respectively. Statistical analysis growth data was performed using ANOVA and Duncan's multiple test at 2% probability level.
Results: The algal growth significantly decreased in N. oculata cells treated with the 5-50 mg/L of Ag-NPs. The increase of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) as well as the decrease of monounsaturated fatty acids (MUFAs) contents were also observed in response to 25 mg/L of Ag-NPs in compared to the control. The important indicators of biodiesel oxidative stability containing LCSF, CFPP and CP increased in N. oculata exposed to Ag-NPs, while the level of DU decreased. The results of this study showed that despite the toxicity of silver nanoparticles, this nanoparticle can increase the biodiesel stability produced from N. oculata.
Azin Fahim, Mohammad Reza Kalbassi, Abdolmohammad Abedian Kenari, Mohammad Sadegh Sabet,
Volume 11, Issue 4 (12-2022)
Abstract
The aim of this study is to investigate the changes in fatty acid composition in Nannochloropsis oculata microalgae under physicochemical stresses (light intensity and salinity). In this regard, the growth rate, the amount of chlorophyll and carotenoid, the approximate analysis and the profile of fatty acid changes of marine microalgae N. oculata under two mutual stresses of salinity (15, 25 and 40 g/l) and light intensity (Lux 1500 and Lux 10000) which at the end of the phase Logarithms were applied are examined. The results showed that according to the application of stresses after the completion of growth, there was no significant difference in the growth rate in different treatments (P>0.05). Also, despite the fact that the highest amount of lipid was obtained under the salinity treatment of 40 g/l and the light intensity of Lux 1500, the highest amount of saturated fatty acids (SFA) was obtained under the treatment of salinity of 15 g/l and the light intensity of 10000 Lux, the highest amount of monounsaturated fatty acids (MUFA) under 25 g/l treatment and 10000 Lux light intensity and the highest amount of polyunsaturated fatty acids (PUFA) under 15 g/l treatment and 10000 Lux light intensity were obtained after 4 days of stress. Considering the effectiveness of fatty acid compounds in N. oculata microalgae, by controlling the cultivation conditions, the maximum amount of desired fatty acids can be achieved in accordance with the desired goals.
