Design and Performance of a Photobioreactor Utilizing Spatial Light Dilution

2010 ◽  
Author(s):  
Dan Dye ◽  
Jeff Muhs ◽  
Byard Wood ◽  
Ron Sims
Keyword(s):  
Specific Growth ◽  
State University ◽  
Utah State University ◽  
Microalgal Biomass ◽  
Energy Conversion Process ◽  
Photobioreactor Design ◽  
And Performance ◽  
Specific Growth Rates ◽  
Kinetics Of ◽  
Volumetric Yield

A photobioreactor with an optical system that spatially dilutes solar photosynthetic active radiation has been designed, built, and tested at the Utah State University Biofuels Center. This photobioreactor could be used to produce microalgal biomass for a number of purposes, such as feedstock for an energy conversion process or high-value products such as pharmaceuticals and nutraceuticals. In addition, the reactor could be used to perform services such as removing nitrates, phosphates, and other contaminants from waste water, as well as scrubbing toxic gases and carbon dioxide from flue gas. Preliminary tests were performed that compared growth and productivity kinetics of this reactor with that of a control reactor simulating a pond. Tests indicated higher specific growth rates and higher areal and volumetric yields compared with the control reactor. The maximum specific growth rate, volumetric yield, and areal yield were 0.21 day−1, 0.059 gm L−1 day−1, and 15 gm m−2 day−1, respectively. Over 10 days of sequential-batch operation, the prototype photobioreactor converted direct-normal solar energy to energy stored in biomass at an average efficiency of 1%. The areal productivity, as mass per aperture per time, was three times higher than that of the control reactor, indicating the photobioreactor design investigated holds promise.

Design and Performance of a Solar Photobioreactor Utilizing Spatial Light Dilution

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
Dan Dye ◽  
Jeff Muhs ◽  
Byard Wood ◽  
Ron Sims
Keyword(s):  
Specific Growth ◽  
State University ◽  
Utah State University ◽  
Microalgal Biomass ◽  
Energy Conversion Process ◽  
Photobioreactor Design ◽  
And Performance ◽  
Specific Growth Rates ◽  
Kinetics Of ◽  
Volumetric Yield

A photobioreactor with an optical system that spatially dilutes solar photosynthetic active radiation has been designed, built, and tested at the Utah State University Biofuels Center. This photobioreactor could be used to produce microalgal biomass for a number of purposes, such as feedstock for an energy conversion process, or high-value products, such as pharmaceuticals and nutraceuticals. In addition, the reactor could be used to perform services such as removing nitrates, phosphates, and other contaminants from waste water, as well as scrubbing toxic gases and carbon dioxide from flue gas. Preliminary tests were performed that compared growth and productivity kinetics of this reactor with that of a control reactor without spatial light-dilution. Tests indicated higher specific growth rates and higher areal and volumetric yields compared with the control reactor. The maximum specific growth rate, volumetric yield, and areal yield were 0.21 day−1, 0.059 gm l−1 day−1, and 15 gm m−2 day−1, respectively. Over 10 days of sequential-batch operation, the prototype photobioreactor converted direct-normal solar energy to energy stored in biomass at an average efficiency of 1%. The areal productivity, as mass per aperture per time, was three times higher than that of the control reactor, indicating the photobioreactor design investigated holds promise.

scholarly journals Effect of Pulsed Electric Fields on the Growth and Acidification Kinetics of Lactobacillus delbrueckii Subsp. bulgaricus

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1146
Author(s):  
Kaidi Peng ◽  
Mohamed Koubaa ◽  
Olivier Bals ◽  
Eugène Vorobiev
Keyword(s):  
Electric Fields ◽  
Growth Rates ◽  
Specific Growth ◽  
Pulsed Electric Fields ◽  
Lactobacillus Delbrueckii ◽  
Accelerated Growth ◽  
Specific Growth Rates ◽  
The Impact ◽  
Kinetics Of ◽  
Lactobacillus Delbrueckii Subsp

The aim of this work was to investigate the effect of pulsed electric fields (PEF) on the growth and acidification kinetics of Lactobacillus delbrueckii subsp. bulgaricus CFL1 during fermentation. The PEF treatments were applied during the fermentation process using a recirculation pump and a PEF treatment chamber coupled with a PEF generator. The medium flow rate through the chamber was first optimized to obtain the same growth and acidification kinetics than the control fermentation without medium recirculation. Different PEF intensities (60–428 V cm−1) were then applied to the culture medium to study the impact of PEF on the cells’ behavior. The growth and acidification kinetics were recorded during the fermentation and the specific growth rates µ, pH, and acidification rate (dpH/dt) were assessed. The results obtained showed a biphasic growth by applying high PEF intensities (beyond 285 V cm−1) with the presence of two maximal specific growth rates and a decrease in the acidification activities. It was demonstrated that the cells were stressed during the PEF treatment, but presented an accelerated growth after stopping it, leading thereby to similar absorbance and pH at the end of the fermentation. These results show the great potential of PEF technology to be applied to generate low acidified products by performing PEF-assisted fermentations.

Heat Production and Growth Kinetics of E. coli K12 from Flow Calorimetric Measurements on Chemostat Cultures

1989 ◽  
Vol 44 (11-12) ◽  
pp. 1036-1048 ◽  
Author(s):  
H. P. Leiseifer
Keyword(s):  
Heat Production ◽  
Growth Rates ◽  
Specific Growth ◽  
Batch Cultures ◽  
E Coli ◽  
Chemostat Cultures ◽  
Basic Parameters ◽  
Specific Growth Rates ◽  
The Relationship ◽  
Kinetics Of

The heat production of E. coli K12 growing aerobically in glucose limited chemostat cultures is determined in the range of specific growth rates μ ( = dilution rates D) from 0,058 h-1 to 0.852 h-1 for two different glucose concentrations Se in the instream of the chemostat. namely Se1=0.3182 g·1-1 and Se2 = 0.6364 g·1-1. Heat production Q and biomass production P per unit of culture volume show well correlated patterns for Se1 and Se2. For Se1 the highest value Q actually measured is 443-10-3 W·1-1 at D = 0.74 h-1 with P = 0.068 g·1-1·h-1 and for Se2 593·10-3 W·1-1 at D = 0.497 h-1 with P = 0.108 g·1-1·h-1. Heat production QB per unit of biomass appears to be independent of Se at least up to D - 0.5 h-1.At higher D there is strong indication that QB possesses a real maximum. The highest value of QB actually measured is 4.8 W·g-1 at D = 0.74 h-1. For Se1 and Se2 there were significantly higher specific growth rates verified in chemostat culture than μmaxBatch= 0.717 h-1 which is the maximum specific growth rate in comparable, unlimited batch cultures. The real maximum of QB is estimated to be in the vicinity of μmaxBatch. This suggests the hypothesis of a maximum principle for the growth in batch culture. For Se1 a closed analytical expression is derived for the relationship between μ and the substrate concentration S. μ[S] features a S-shaped characteristic with μmaxChemostat= 0.905 h-1; 1/2 μmaxChemostat is reached at S = 2.85·10-3 g·1-1. Three basic parameters which characterize the overall metabolism of the cells, namely the heat released per unit of substrate consumed, (Qs, the effective yield of biomass, Yeff, and μmaxChemostat are identified to depend on Se.

scholarly journals EFFECTS OF DEPTH AND CONCENTRATION OF DIGESTATE ON GROWTH OF THREE MICROALGAL SPECIES

2016 ◽  
Vol 54 (5) ◽  
pp. 591 ◽  
Author(s):  
Nguyen Tran Thien Khanh
Keyword(s):  
Specific Growth ◽  
Low Cost ◽  
Middle Layer ◽  
Bottom Layer ◽  
Cell Number ◽  
Continuous Illumination ◽  
Microalgal Biomass ◽  
Specific Growth Rates ◽  
Counting Cell ◽  
Microalgal Species

In order to design a culture system for microalgal biomass production with a low cost and convenient cell collection, growth performance of mixtures of microalgal cells, including Euglena gracilis, Chlorella vulgaris, and Dunaliella tertiolecta cultured in a volume of 1 L were investigated at a PPFD of 300 µmol m-2 s-1 at the surface of the solution with continuous illumination at 30 °C. Each culture container contained diluted digestate at concentrations of 5, 10, 15, 20, and 50 %. Sample cells for counting cell number were collected daily at three depths: 0–50 mm (the surface layer), 10–15 mm (the middle layer), and 25–30 mm (the bottom layer). Pseudo-specific growth rates (ms) of each species at each depth were calculated as cellular multiplication rates using number of cells per time. In each layer, the average ms of each species was highest in 5 % digestate. The average ms of all three microalgal species (0.035 h-1) was observed in all layers in 5 % digestate solution. The ms of each species was highest in the bottom layer in 5% digestate (0.048 h-1, 0.041 h-1, and 0.022 h-1, respectively for C. vulgaris, E. gracilis, and D. tertiolecta). In conclusion, E. gracilis, C. vulgaris, and D. tertiolecta showed the highest specific growth rate in 5 % digestate in all layer.

scholarly journals Effect of Environmental Factors on Growth Kinetics of Biocontrol Agent Bacillus thuringiensis Bacterium using 2L and 5L A+ Sartorius Stedim Biostat® Fermentation Systems

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
C. S. Richardson ◽  
D. Upadhyay ◽  
S. Mandjiny ◽  
L. Holmes
Keyword(s):  
Growth Rate ◽  
Bacillus Thuringiensis ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Doubling Time ◽  
Specific Growth ◽  
Optimal Conditions ◽  
Specific Growth Rates ◽  
Kinetics Of

Bacillus thuringiensis (Bt) is a soil-dwelling, Gram-positive bacterium that is used as a biological pesticide and used to genetically engineer plants due to the toxic proteins it produces. B. thuringiensis was studied in batch cultures to determine the specific growth rates and doubling times. The purpose of this experiment was to research the growth kinetics of Bacillus thuringiensis in a 2L bioreactor and a 5L bioreactor containing growth media at different environmental conditions. Fermentation parameters were controlled by utilizing a Sartorius Stedim Biostat® A+ bioreactor system for bacterial growth. The environmental conditions included temperature, agitation, and aeration. The specific growth rates of B. thuringiensis were determined. The optimal conditions for the 2L bioreactor were 200 RPM, 30°C, 1.5 VVM, and with the highest specific growth rate 0.30 hr and the shortest doubling time 2.3 hr. For the 5L bioreactor, the optimal conditions were 150 RPM, 30°C, 1.5 VVM, and with the highest specific growth rate 1.2 hr and the fastest doubling time 0.6 hr.

scholarly journals Impact of salinity on the kinetics of CO2 fixation by Spirulina platensis cultivated in semi-continuous photobioreactors

2021 ◽  
Vol 46 (1) ◽  
pp. 21-34
Author(s):  
Javier Christian Ramirez-Perez ◽  
Harry Janes
Keyword(s):  
Kinetic Parameters ◽  
Spirulina Platensis ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Fixation ◽  
Specific Growth ◽  
Co2 Concentration ◽  
Co2 Removal ◽  
Co2 Biofixation ◽  
Photobioreactor Design ◽  
Kinetics Of

In this research, the physiological response of the microalgae Spirulina platensis to salinity stress (1 and 100 g L-1 ) was investigated. Spirulina platensis and Spirulina platensis (adapted to high salt concentration) were operated at laboratory scale in a semi-continuous photobioreactors. The responses examined were within 0.5 to 10% CO2 concentration, temperatures from 10 to 40 oC, light intensities from 60 to 200 μmol m-2 s -1 and presented better results in terms of all kinetic parameters. The highest rate of CO2 biofixation for Spirulina platensis was 25.1 gCO2 m-3 h -1 , and the maximum specific growth (μmax) achieved was 0.44 d-1 - 0.67 d-1 at 2.5% CO2, 150 µmol m-2 s -1 at 25 oC. Corresponding determined values of Spirulina platensis adapted were 18.2 gCO2 m-3 h -1 , 0.31 d-1 - 0.58 d-1 at 2.5% CO2, 60 µmol s-1 m-2 and 28 oC. However, both microalgae exhibited experimental limiting growth factors, CO2 10%, 40 oC and 200 µmol m-2 s -1 , conditions under which photosynthetic CO2 biofixation may be inhibited and photoinhibition of photosynthesis may be enhanced by salinity. The efficiency of 2.5% CO2 removal by Spirulina platensis achieved 99%, whereas Spirulina platensis adapted to 96%, respectively. The kinetic parameters estimated for Spirulina platensis can be used to improve photobioreactor design for reducing of atmospheric carbon dioxide.

The Growth Kinetics of Isochrysis Galbana in Cultures Containing Sublethal Concentrations Of Mercuric Chloride

1974 ◽  
Vol 54 (1) ◽  
pp. 157-169 ◽  
Author(s):  
Anthony G. Davies
Keyword(s):  
Growth Kinetics ◽  
Specific Growth ◽  
Isochrysis Galbana ◽  
Enzyme Reaction ◽  
Toxic Substances ◽  
Enzyme Reactions ◽  
Specific Growth Rates ◽  
Kinetics Of ◽  
Sublethal Concentrations ◽  
Effect Of Inhibitors

There is increasing evidence that the specific growth rates of phytoplankton are hyperbolically related to the intracellular concentrations of rate-determining nutrients by expressions of the Michaelis-Menten type used in the study of enzyme reaction kinetics (see, for example, Caperon, 1968; Droop, 1968; Davies, 1970; Paasche, 1973). This has led us to inquire whether there might also be relationships, analogous to those which describe the effect of inhibitors upon the rates of enzyme reactions (Dixon & Webb, 1958) which can be applied to the growth of phytoplankton in the presence of sublethal levels of toxic substances.

Oscillating conditions for influencing the composition of mixed biological cultures

1998 ◽  
Vol 37 (4-5) ◽  
pp. 259-262 ◽  
Author(s):  
Bjarne R. Horntvedt ◽  
Morten Rambekk ◽  
Rune Bakke
Keyword(s):  
Growth Rate ◽  
Specific Growth ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Rate Reduction ◽  
Similar Strategy ◽  
Sinusoidal Oscillations ◽  
Specific Growth Rates ◽  
Rate Limiting ◽  
Concentration Levels

This paper presents a strategy in which mixed biological cultures are exposed to oscillating concentration levels, to improve the potential for coexistence of desired bacterial species. A mechanistic mathematical model is constructed to investigate and illustrate this strategy. This paper is focused on competition between nitrifying, denitrifying and aerobic heterotrophic bacteria in a CSTR with sludge recycle. For nitrifying and aerobic heterotrophic cultures, the effect of sinusoidal oscillations in DO levels with an amplitude of 1.0 mg/l is a 16% specific growth rate reduction compared to that at a constant DO level. The denitrifiers growth rate is increased by an average of 59%, compared to the constant DO level situation. A similar strategy has been tested in a pilot plant. It is concluded that the influence on specific growth rates is a function of the amplitude of the oscillations. The effects are greatest when concentrations fluctuate around the half saturation concentration of the rate limiting component(s).

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