Impact of light quality on a native LouisianaChlorella vulgaris/Leptolyngbyasp. co-culture (original) (raw)
Related papers
Impact of light quality on a native Louisiana Chlorella vulgaris /Leptolyngbya sp. co-culture
Engineering in Life Sciences, 2017
Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanobacteria have photosynthetic pigments that can capture photons of wavelengths not available to chlorophylls. A native Louisiana microalgae (Chlorella vulgaris) and cyanobacteria (Leptolyngbya sp.) co-culture was used to study the effects of light quality (blue-467 nm, green-522 nm, red-640 nm and white-narrow peak at 450 nm and a broad range with a peak at 550 nm) at two irradiance levels (80 and 400 μmol m −2 s −1) on the growth, species composition, biomass productivity, lipid content and chlorophyll-a production. The co-culture shifted from a microalgae dominant culture to a cyanobacteria culture at 80 μmol m −2 s −1. The highest growth for the cyanobacteria was observed at 80 μmol μmol m −2 s −1 and for the microalgae at 400 μmol m −2 s −1. Red light at 400 μmol m −2 s −1 had the highest growth rate (0.41 d −1), biomass (913 mg L −1) and biomass productivity (95 mg L −1 d −1). Lipid content was similar between all light colors. Green light had the highest chlorophyll-a content (1649 μg/L). These results can be used to control the species composition of mixed cultures while maintaining their productivity.
Egyptian Journal of Botany, 2019
Algae are a diverse group of photosynthetic organisms. They are classified to microalgae and macroalgae, they are present in aquatic and terrestrial ecosystems. Microalgae are microscopic organisms, including a huge variety of species. Microalgae require three main components for their growth including sunlight, nutrients from the water, and carbon source such as CO 2 from the air, they release about 50% of the atmospheric oxygen (Nigam & Singh, 2011). Nowadays, there is a wide field of applications which depends on microalgae. They can produce valuable materials including carotenoids, lipid, natural dye, polyunsaturated fatty acid, peptide, toxin, sterols, phenolic compounds, immune modulators, agars, agarose, alginates, carrageenans and vitamin B (Wen & Chen, 2003; He et al., 2005). They can be used for aquaculture feeds, animal, human nutrition supplements, pharmaceuticals, cosmetic products, pigments and biofertilizer. They can be used for extracting high-value molecules, stable isotope C HLORELLA vulgaris and Scenedesmus arvernensis are common eukaryotic green microalgae that have a very wide use in various applications. They can be used as raw materials in bio-energy production, in aquaculture nutrition, in pharmaceuticals, cosmetics, biofertilizers, biodegradation of wastes and dyes. So, this required several studies to test some factors that can influence the growth rate and evaluate their yield. This study investigated the effects of different media compositions: Bold's basal medium, BG-11 medium, modified Chu-10 medium, and Kuhl's medium on growth of C. vulgaris and S. arvernensis. Then, study the effect of four different light intensities on the growth rate using the optimized medium. The growth was recorded by estimating optical density (OD), cell counting (CC) and total chlorophyll contents. The results showed that the maximum growth was recorded at Modified CHU's 10 medium for C. vulgaris and BG-11 medium for S. arvernensis. The growth was compared with the initial record of C. vulgaris and S. arvernensis inocula; the OD increased by 6.85 and 5.15 times, respectively. C. vulgaris showed the optimum CC 9.60 times and total chlorophyll 7.96 times. CC recorded 10.42 times and total chlorophyll increased 5.90 times for S. arvernensis. Light intensities experiment showed that C. vulgaris gave the best growth rate at 60 μmol photons m-2 s-1 , on the 35 th day of cultivation with increasing in OD, CC and total chlorophyll, (6.18, 5.27 and 3.58 times), of the initial record, respectively. Concerning S. arvernensis optimum growth rate was reached at 40μmol photons m-2 s-1 , on the 35 th day accompanied by an increment in OD, CC and total chlorophyll, (6.20, 4.55 and 10.04 times), of the initial record, respectively.
Effect of Light Intensity and Quality on Growth Rate and Composition of Chlorella vulgaris
Plants
In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster g...
Enhanced algae growth in both phototrophic and mixotrophic culture under blue light
Bioresource Technology, 2011
Biomass productivity and fatty acid methyl esters (FAME) derived from intracellular lipid of a Nannochloropsis sp. isolated from Singapore's coastal waters were studied under different light wavelengths and intensities. Nannochloropsis sp., was grown in both phototrophic and mixotrophic (glycerol as the carbon source) culture conditions in three primary monochromatic light wavelengths, i.e., red, green and blue LEDs, and also in white LED. The maximum specific growth rate (l) for LEDs was blue > white > green > red. Nannochloropsis sp. achieved a l of 0.64 and 0.66 d À1 in phototrophic and mixotrophic cultures under blue lighting, respectively. The intracellular fatty acid composition of Nannochloropsis sp. varied between cultures exposed to different wavelengths, although the absolute fatty acid content did differ significantly. Maximum FAME yield from Nannochloropsis sp. was 20.45% and 15.11% of dry biomass weight equivalent under photo-and mixotrophic culture conditions respectively for cultures exposed to green LED (550 nm). However, maximum volumetric FAME yield was achieved for phototrophic and mixotrophic cultures (i.e., 55.13 and 111.96 mg/l, respectively) upon cell exposure to blue LED (470 nm) due to highest biomass productivity. It was calculated that incremental exposure of light intensity over the cell growth cycle saves almost 20% of the energy input relative to continuous illumination for a given light intensity.
Journal of Applied Phycology
Light (quantity and quality) is the main growth limiting factor of photoautotrophic microalgae. The integration of selective permeable photovoltaic filters above microalgae cultivation systems has been proposed previously to improve both production efficiencies and economics. In order to optimize such system, we evaluated the growth and photosynthesis of two spectrally acclimated strains of Nannochloropsis sp. (MUR 266 and MUR 267) grown semi-continuously under different light spectra in this study. No significant differences in biomass productivity were observed between cultures acclimated under full blue (BL, 400-525nm), and narrow blue (LEDB, 430-490nm) light when compared to the positive control of white light (WL, 400-700nm) while lower values were recorded under red (RL, 600-700nm) and pink light (PL, 400-525, 600-700nm) for both species. When compared to WL, the photosynthetic performance (Fq′/Fm′, αETR, ETRmax) of both species was higher under both BL and LEDB except for the Fq′/Fm′ of MUR 267 under LEDB. Chlorophyll a content was highest in cultures acclimated to RL while values tended higher under LEDB, RL and PL for MUR 267. Total lipid yield of both MUR 266 and MUR 267 was higher under BL and PL respectively than WL. Based on the results of this study, theoretical modelling of the proposed photovoltaic-microalgae system indicate approximately 150-210 W m-2 of electricity could be potentially generated if only blue wavelengths (BL and LEDB) are selectively filtered from sunlight while converting the remaining unused spectrum of sunlight into electricity.
Energies
Microalgae are a practical source of biological compounds for biodiesel production. This study examined the influence of three different light-emitting diode (LED) systems on the biomass production of green algae Chlorella vulgaris BA0002a. The cultivation was carried out in a photobioreactor illuminated from the bottom with a single side light jacket (PBR I), in a photobioreactor illuminated from the bottom with a double side light jacket (PBR II) and in a photobioreactor illuminated only from the top (PBR III). Research has shown that the intensification of algae cell production and growth depends on the light distribution and exposure time of a single cell to radiation. In the experiment, the highest growth of algae cells was obtained in the photobioreactor with double jacket and lower light panel. The lowest cell growth was observed in the photobioreactor illuminated only from above. For cultures raised in the PBR I and PBR II photobioreactors, increased oxygen production was ob...
Effect of light conditions on mixotrophic cultivation of green microalgae
Bioresource Technology, 2019
Current research aimed to increase mixotrophic biomass from various organic carbon sources by exploring best light conditions. Three substrates glucose, acetic acid and glycerol were studied for their effects on mixotrophic microalgae cultivation under four light conditions. Light irradiance exhibited variability in growth response and photosynthetic efficiency based on type of substrates used in mixotrophic growth. Each substrate showed variability in light requirements for their effective assimilations. From growth responses, glucose and acetic acid respectively exhibited heterotrophic and mixotrophic (better growth in light) natures. Continuous light-deficient condition was adequate for effective mixotrophic growth as well as energy saving for glucose. However, light-sufficient condition required for effective acetic acid supported mixotrophic growth. Mixotrophic benefits from glycerol and its uptake by Chlorella protothecoides was negligible in all light conditions. Investigation of heterotrophic biomass contribution by various substrates in overall mixotrophic yield, glucose offered maximum approx. 43% contribution.