Impact of biomass density on growth rates of Spirulina platensis under different light spectra (original) (raw)
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A Review of Effect of Light on Microalgae Growth
Algae-organisms are unicellular or simple multicellular body plant that is able to manufacture their own food material by photosynthesis. Algae can be cultivated under certain conditions of temperature, light and sufficient nutrients to produce biodiesel. Many researchers worked to increase the efficiency of the production rate in both indoor and outdoor cultivating systems and by designing special photobioreactors (PBRs) to increase the rate of photosynthesis. Light conditions affect directly the growing and photosynthesis of microalgae. (Duration and intensity).Microalgae needs a light/dark regime for productive photosynthesis, it needs light for a photochemical phase to produce (ATP, NADPH) and also needs dark for biochemical phase synthesize essential molecules for growth. This article critically reviews research under taken to date to study the effect of light on the microalgae growth.
Effects of using light-emitting diodes on the cultivation of Spirulina platensis
Biochemical Engineering Journal, 2007
Various light-emitting diodes (LEDs) with different light wavelengths and illumination intensities were employed to explore the effects of light source on photoautotrophic cultivation of Spirulina platensis. From the experimental results, red LED exhibited the highest specific growth rate of 0.40 (day −1 ) under the condition of 3000 mol m −2 s −1 . Blue LED showed the least efficiency in the conversion of photon to biomass. Hence, a modified Monod model was proposed to fit the specific growth rates of S. platensis from different light sources. The light intensity threshold for minimum photoautotrophic growth was also determined. In comparing the economic efficiency of energy to biomass, the use of red LED gave the most effective performance for the photoautotrophic cultivation.
Journal of Chemical Technology and Biotechnology, 2008
BACKROUND:Spirulina platensis (Toliara, Madagascar) provides a food supplement which can fight against malnutrition and food insufficiency in Madagascar. In this country, the current production from three open basins is not sufficient to cover needs, and presents drawbacks such as low productivity and possible contamination. Thus cultivation of S. platensis in a closed photobioreactor opens the possibility of extending this microalga production. In this study, the influence of colour and intensity of the light on S. platensis growth and protein content was investigated in a bubble column.RESULTS: Growth kinetics were obtained for four colours (green, white, red and blue) and four intensities (400, 800, 1000 and 1200 lux) of light. The influence of light colour on Spirulina growth was discussed. The highest productivity (183.6 mg L−1 d−1) and concentration (2643 mg L−1) were obtained for green light at 1200 lux. The protein content was 58%.CONCLUSION: Using green light allows improvement of S. platensis growth. Performance obtained with the closed system was higher than that reported in the literature. Copyright © 2008 Society of Chemical Industry
Biomass and Bioenergy, 2004
The in uence of light intensity reduction on Spirulina platensis cultivation was investigated, using urea and KNO3 as nitrogen sources. The reduction of light intensity from 5 to 2 klux was studied both on the 9th and the 13th day of cultivation. Increases of up to 29% in the total chlorophyll production were observed for the cultivations with light intensity reduction, in comparison with the cultivations carried out at ÿxed light intensities. ?
Biochemical Engineering Journal, 2010
Light-emitting diodes (LEDs) with various light wavelengths (red, yellow, green, blue and white) and various levels of light intensity (750, 1500 and 3000 mol m −2 s −1 ) are applied to study the effects of light sources on chlorophyll a (Chl) and phycocyanin (Phy) production of Spirulina platensis. Logistic rate equations are used to depict the kinetic behavior of algal growth and pigments formation under various light sources and intensities. According to the regression results, a red LED is the best for algae growth. On the other hand, yellow light gives the best specific Chl production rate with a light intensity of 750 or 1500 mol m −2 s −1 , and blue light yields the best specific pigments (for Chl and Phy) production rates at 3000 mol m −2 s −1 . From the model fitting results, it is found that, at a higher light intensity, a higher specific Chl production rate accompanied by a higher S. platensis biomass is obtained. However, as for Phy production, a higher biomass results in a lower specific Phy production rate. The only exception is the use of blue light, which shows a positive effect on both Chl and Phy production rates under a higher light intensity.
Response of Spirulina platensis C1 to High Temperature and High Light Intensity
Kasetsart Journal - Natural Science
Response of Spirulina platensis strain C1 to high temperature and high light intensity was studied. Specific growth rate of the S. platensis C1 cells grown in batch cultures at 35°C with a light intensity of 100 μE/m2/s was 0.0247 h-1. The specific growth rate decreased to 0.008 h-1 at 43°C, which was designated to be the critical temperature for this alga strain C1. A suddenly increasing in light intensity from 100 to 500 μE/m2/s showed an impact to the cell growth, which it had significant affects to photosynthesis (as O2-evolution) as well as its pigment content (chlorophyll and phycocyanin). However, a less effect on the alga growth was obtained when the cells were shifted to grow at higher temperature of 43°C. The alga cells grown at high temperature with high light intensity resulted in decreasing protein content while carbohydrate content increased. The fatty acid profiles of the cells grown at high temperature exhibited a decrease in polyunsaturated fatty acid (C18:3Δ6,9,12)...
Bioresource Technology, 2020
LEDs have specific wavelengths that can positively influence the production of microalga biomass and biomolecules of interest. Filling the gaps in the literature, this study evaluated the effect of different LED wavelengths and photoperiods on protein productivities and free amino acid (FAA) profile of Spirulina sp. LEB 18 cultures. The best protein productivity results were obtained in red and green LED cultures using integral and partial photoperiods, respectively. In these experiments, protein productivities increased 2 and 1.6 times, respectively, compared to the control culture using fluorescent light. Green LEDs in partial photoperiod provided also the highest concentrations of essential and non-essential FAA, about 1.8 and 2.3 times higher, respectively, than control cultures. LEDs showed to be a promising sustainable light source for increasing protein productivity and FAA concentration in Spirulina sp. LEB 18 cultures.
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