Increase of Copper Toxicity to Growth of Chlorella vulgaris with Increase of Light Intensity

1998 ◽  
Vol 35 (2) ◽  
pp. 193-198 ◽  
Author(s):  
F.M. Lupi ◽  
H.M.L. Fernandes ◽  
I. Sá-Correia
Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria N. Metsoviti ◽  
George Papapolymerou ◽  
Ioannis T. Karapanagiotidis ◽  
Nikolaos Katsoulas

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 growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).


2016 ◽  
Vol 42 (2) ◽  
pp. 191-200
Author(s):  
NJ Tarin ◽  
NM Ali ◽  
AS Chamon ◽  
MN Mondol ◽  
MM Rahman ◽  
...  

Isolation and characterization of Chlorella vulgaris (green alga) and Anabaena variabilis (cyanobacterium) were made from natural and artificial water bodies of Dhaka University and Khulna, Bangladesh from March through December 2014 using modified Chu-10D medium to determine their potential as feedstock for biofuel production. Optimum growth measured as total chlorophyll and optical density under varying physical and chemical environments was determined. The optimum growth for C. vulgaris was obtained at pH 6.5 under light intensity of 110 μE m-2 s-1 and one and a half times the concentration of the Chu-10D. Compared to this, the optimum growth for A. variabilis was obtained at 7.0 pH, 90 μE m-2 s-1 light intensity and normal Chu 10D. Both organisms were grown at 25o C temperature. Aeration of medium showed a significant positive growth for both the isolates. Supplementation of medium with vitamin B1, B6, B7 and B12 would yield higher biomass of C. vulgaris as biofuel feedstock. Vitamins were not required for growing A. variabilis. Asiat. Soc. Bangladesh, Sci. 42(2): 191-200, December 2016


2020 ◽  
Vol 92 (9) ◽  
pp. 1225-1226
Author(s):  
T. Hernández Rodríguez ◽  
S. Deppe ◽  
V. Gassenmeier ◽  
F. Kuhfuss ◽  
M. Tölle ◽  
...  

Industrial waste disrupts the natural production of microalgae cultures. Cultivation of microalgae in a controlled environment highly results to biomass with lower contamination necessary as high-valued economic product. In response to the emerging challenges of sustainable energy production, the integration of computational intelligence and biosystems engineering is considered as an open research area. In this study, Chlorella vulgaris microalgae were cultivated in BG-11 growth medium on three customized surface-mount light bioreactors that are equipped with digital camera for growth monitoring in terms of accumulated biomass surface area and color reflectance intensity via IoT. Feature-based machine learning models predicted microalgae growth area in terms of water temperature, pH level and turbidity, and light intensity. Microalgae cultures were exposed to combinations of white artificial light source of 2000 ± 1000 lux and water temperature of 27 ± 5°C using Peltier plate to discriminate biomass growth within a 30-day cultivation period. A total of nine environmental conditions were employed to clearly discriminate the impacts of environmental stressors to microalgae growth. Combined neighborhood component analysis and ReliefF was used to select high impact color features of C, Ye, M, H, and S with biomass area. Electromagnetism-like mechanism optimized-RBNN bested RNN and generalized processing regression with R2 of 0.985 and RMSE of 6.262. There is also considerable growth in biomass surface area for certain combinations of light intensity and water temperature (2125 ± 625 lux and 28.75 ± 3.25°C), and turbidity and water pH concentrations (3.85 ± 0.15 NTU and 8.025 ± 0.775). However, the photobioreactor with 27°C and 2000 lux exposure is considered having the exact optimum controlled environment condition in cultivating Chlorella vulgaris based on the generated growth in biomass surface area of 38.314%. This developed intelligent system is scalable for seamless microalgae production of any strands for renewable energy resource.


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