Modified equation of chlorophyll content in microalgal biomass under light limitation

2020 ◽  
pp. 17-24
Author(s):  
Alexander S. Lelekov ◽  
Rudolf P. Trenkenshu ◽  
Tatyana M. Novikova
Keyword(s):  
Chlorophyll Concentration ◽  
Arthrospira Platensis ◽  
Light Limitation ◽  
Specific Rate ◽  
Microalgal Biomass ◽  
Basic Model ◽  
Microalgae Biomass ◽  
Rate Of Photosynthesis ◽  
Species Specific ◽  
Irradiation Parameter

The paper presents a modified mathematical model of light-dependent chlorophyll concentration in the microalgae biomass. The basic model is based on the concept of biomass as a sum of reserve and structural components. Considering that part of the structural biomass can turn into a reserve, the minimum irradiation parameter (“photosynthesis compensation point”) is added to the basic equation. Verification of the model on experimental data for turbidostat cultures of Tetraselmis viridis and Arthrospira platensis allowed us to evaluate species-specific coefficients. The obtained coefficient values are similar for both species. The share of chlorophyll in structural biomass is about 2 %, the maximum share of structural forms of biomass is 84 %, the economic conversion factor of reserve biomass to structural is 80–90 %, and the maximum specific rate of photosynthesis is 14–20 times higher than the rate of endogenous consumption of biomass.

scholarly journals Modeling Of Chlorophyll a Content in Microalgae Cultures

2020 ◽  
Vol 15 (2) ◽  
pp. 158-171 ◽  
Author(s):  
A.S. Lelekov ◽  
R.P. Trenkenshu
Keyword(s):  
Chlorophyll A ◽  
Arthrospira Platensis ◽  
Basic Model ◽  
Cell Structures ◽  
Kinetic Coefficients ◽  
Microalgae Biomass ◽  
Species Specific ◽  
Specific Growth Rates ◽  
Chlorophyll A Content ◽  
Good Agreement

The work focuses on mathematical modeling of light influence mechanisms on chlorophyll a content in microalgae biomass. The well-known qualitative models are based on concepts of synthesis and photodestructive oxidation of chlorophyll a, however the later for some microalgae species seems doubtful. We proposed an alternative approach to modeling the light-dependent chlorophyll a content in microalgae biomass. The basic model is based on generally accepted two-stage photoautotrophic growth of microalgae. At the first stage, during photosynthesis a reserve part of biomass is formed, from which the biosynthesis of cell structures occurs at the second stage. Three partial solutions of the basic system of equations describing the dependence of chlorophyll a content on the external light intensity are considered for various limiting conditions. Due to the equality of specific growth rates of formation of reserve and structural forms of biomass, the equations obtained can be used only for turbidostat cultures. Verification of the obtained equations for Arthrospira platensis allows us to estimate kinetic coefficients, the values of which are generally in good agreement with theoretically calculated ones. For approximate calculations, a simple equation is proposed that shows a good agreement with experimental data for Tetraselmis viridis (R2 = 0.98), Dunaliella tertiolecta (R2 = 0.92) and describes the results for Sceletonema costatum and Chlorella vulgaris (R2 = 0.8) quite well. Chlorophyll a refers to structural forms of biomass. The proportion of chlorophyll a in the structural biomass is about 2.5–3.5 %, it is a species-specific parameter.

scholarly journals Effects of Liquid Digestate Treatment on Sustainable Microalgae Biomass Production

2021 ◽  
Author(s):  
Marta Kisielewska ◽  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Joanna Kazimierowicz ◽  
Piera Quattrocelli ◽  
...  
Keyword(s):  
Growth Medium ◽  
Biomass Production ◽  
Culture Medium ◽  
Culture Media ◽  
Biomass Concentration ◽  
Arthrospira Platensis ◽  
Microalgal Biomass ◽  
Liquid Digestate ◽  
Microalgae Biomass ◽  
High Treatment

AbstractThe aim of the study was to investigate the potential of microalgal cultivation on anaerobic liquid digestate as a growth medium. The two methods of liquid digestate treatment including centrifugation and distillation and the two algal strains (Chlorella vulgaris and Arthrospira platensis) were compared. Additionally, the volume of the liquid digestate used to prepare the culture medium constituted from 10 to 50% of the medium volume. The study demonstrated that the highest C. vulgaris and A. platensis biomass productions of 2490 mg TS/L and 2990 mg/L, respectively, were obtained by adding 50% of distilled digestate to a growth medium. Regarding centrifuged liquid digestate, only 10% dilution was required to obtain the maximum final biomass concentration. A. platensis removed 81.1% and 66.4% of the total nitrogen from medium prepared on distilled and centrifuged digestate, respectively, while C. vulgaris ensured 64.1% and 47.1% of removal, respectively. The phosphorus removal from both culture media was higher than 94.2% with A. platensis, while it was 70.4% from distilled and 87.4% from centrifuged media with C. vulgaris. The study confirmed a great potential of microalgal biomass production on anaerobic liquid digestate with a high treatment efficiency of digestate.

scholarly journals Chlorophyll concentration in marine microalgae biomass under the condition of light limitation (model)

2019 ◽  
Vol 4 (4) ◽  
pp. 100-102 ◽  
Author(s):  
R. P. Trenkenshu ◽  
T. M. Novikova
Keyword(s):  
Mathematical Model ◽  
Chlorophyll Concentration ◽  
Marine Microalgae ◽  
Experimental Results ◽  
Light Limitation ◽  
Microalgae Biomass ◽  
Tetraselmis Viridis

The paper presents a mathematical model of light-dependent chlorophyll concentration in the marine microalgae biomass. The model is based on the concept of biomass as the sum of reserve and structural macromolecular forms of organic cell matter. At the same time, chlorophyll refers to structural forms of biomass. Using such concepts, it is possible to apply known equations for light-dependent content of structural forms in biomass. The proposed equation describes well the experimental results obtained in a number of experiments with the chlorophyllostate culture Tetraselmis viridis.

scholarly journals Sugar and no sugar added fruit microalgae-enriched jams: a study about their physicochemical, rheological, and textural properties

2021 ◽  
Author(s):  
Zaida Natalia Uribe-Wandurraga ◽  
María Bravo-Villar ◽  
Marta Igual ◽  
Carmen Savall ◽  
Purificación García-Segovia ◽  
...  
Keyword(s):  
Food System ◽  
Textural Properties ◽  
Arthrospira Platensis ◽  
Microalgae Biomass ◽  
Textural Parameters ◽  
Weak Gel ◽  
Biomass Extract ◽  
And Control ◽  
Colour Coordinates ◽  
Control Samples

AbstractJams are preparations of fruits whose main preserving agent is sugar. Due to this, health concerns of consumers have resulted in a sugar reduction, and its replacement using alternative sweeteners and introducing new ingredients enhancing nutritional properties. In this study, four types of fruits jams (plum, strawberry, apple, and peach), with or without sugar, were prepared using two microalgae biomass, Arthrospira platensis (Spirulina) and Chlorella vulgaris, and Dunaliella salina extract as ingredients at different mix levels of concentrations, 0.10%–0.10%–0.05% respectively, for plum; 0.04%–0.00%–0.01 respectively, for strawberry; 0.06%–0.04%–0.00% respectively, for apple and 0.00%–0.01%–0.04% respectively, for peach. Physicochemical, rheological, and textural parameters were evaluated. Substitution of sugar/fructose syrup in the jam’s preparation caused changes in pH values, solid soluble content, and rheological and textural properties compared to sugar jams. Using sugar or sweeteners as isomalt, stevia and sucralose and microalgae biomass or extract showed significant changes in colour coordinates, however, these differences were not perceptible by the human eye. Jams containing microalgae biomass-extract showed higher G', G'', G*, and η* values than their corresponding control samples. All the jams presented weak-gel characteristics, distinguishing fruit jams. However, the results of weak-gel model analysis suggest that the influence of the different ingredients in the food system depends not only on their concentration but also on the interactions in the gel structure. Strawberry and apple jams showed no significant differences between microalgae biomass-extract samples and control samples, for both sugar and no sugar added jams being the best-obtained samples.

Influence of Reservoir Transit on Riverine Algal Transport and Abundance

1984 ◽  
Vol 41 (12) ◽  
pp. 1803-1813 ◽  
Author(s):  
D. M. Søballe ◽  
R. W. Bachmann
Keyword(s):  
Water Temperature ◽  
Retention Time ◽  
Standing Crop ◽  
Algal Biomass ◽  
Chlorophyll Concentration ◽  
Light Limitation ◽  
Des Moines ◽  
Flow Dependence ◽  
Major Loss ◽  
Chlorophyll Concentrations

The Des Moines River lost 65–75% of its algal standing crop (chlorophyll a) in passing through each of two impoundments (mean retention times 11 and 16 d), and chlorophyll concentrations within both impoundments were 50–90% below the predictions of empirical chlorophyll–nutrient models. Sedimentation of river-borne algae and light limitation within the impoundments were identified as major loss processes. A reduction in algal size from upstream to downstream in one reservoir paralleled the loss of algal biomass. Algal losses in each impoundment increased with both increasing retention time and water temperature so that chlorophyll concentration below the dams was uncoupled from the temperature and flow dependence seen in river reaches not influenced by impoundments. The reduction in riverine algal transport associated with reservoir transit was cumulative over the two-reservoir series; this reduction can be interpreted as a "reset" to river headwater conditions.

scholarly journals The Application of Catalytic Processes on the Production of Algae-based Biofuels: A Review

2020 ◽  
Author(s):  
Antonio Zuorro ◽  
Janet B. García-Martínez ◽  
Andrés F. Barajas-Solano
Keyword(s):  
Fossil Fuels ◽  
Operating Conditions ◽  
Thermochemical Conversion ◽  
Chemical Components ◽  
High Carbon ◽  
Microalgal Biomass ◽  
Microalgae Biomass ◽  
End Products ◽  
Recent Developments ◽  
Thermochemical Processes

Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, the biocrudes obtained from direct thermochemical conversion have substantial quantities of heteroatoms (oxygen, nitrogen, and sulfur) due to the complexity of the biomass's content of chemical components (lipids, carbohydrates, and proteins). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.

scholarly journals The Application of Catalytic Processes on the Production of Algae-Based Biofuels: A Review

2020 ◽  
Author(s):  
Antonio Zuorro ◽  
Janet B. García-Martínez ◽  
Andrés F. Barajas-Solano
Keyword(s):  
Algal Biomass ◽  
Fossil Fuels ◽  
Operating Conditions ◽  
Thermochemical Conversion ◽  
High Carbon ◽  
Microalgal Biomass ◽  
Microalgae Biomass ◽  
End Products ◽  
Recent Developments ◽  
Thermochemical Processes

Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, because of the complexity of the biomass (lipids, carbohydrates , and proteins), the obtained biofuels from direct thermochemical conversion have large amounts of heteroatoms (oxygen, nitrogen , and sulfur). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.

scholarly journals RESEARCH ON HARVESTING OF MICROALGAE CHLORELLA SP. BY ELECTROCHEMICAL FLOTATION METHOD USING CORROSIVE ELECTRODES

2018 ◽  
Vol 55 (4C) ◽  
pp. 14 ◽  
Author(s):  
Ha Vinh Hung
Keyword(s):  
Current Density ◽  
Colloidal Stability ◽  
Biodiesel Production ◽  
Iron Electrode ◽  
Aluminum Electrode ◽  
Microalgal Biomass ◽  
Flotation Process ◽  
Chlorella Sp ◽  
Commercial Scale ◽  
Microalgae Biomass

Microalgae are a promising feedstock for biodiesel production. Harvesting of microalgal biomass is still a bottleneck to its commercial scale application, due to small cell size, low culture densities, colloidal stability and thus economic disadvantage. The aim of this study was to evaluate the biomass separation of the small size microalgae Chlorella sp. by electrochemical flotation process with rectangle electrodes using aluminum or iron plates. The most effective conditions for this experiment involved the use of an aluminum electrode for 30 min with a current density of 1.5 mA/cm2, whereas the iron electrode has been used ineffectively with the same of conditions. The effect of current density (0.5–3 mA/cm2), concentration of microalgae biomass (0.29–1.5 g/L), and electrolyte (0–2 g/L) for aluminum electrode were analyzed. The highest recovery efficiency of 90 % was obtained for Chlorella sp. at 1.5 mA/cm2 in 30 min and concentration of microalgae biomass of 0.74 - 1.5 g/L with power consumption of 1.36 kWh/kg.  The electrochemical flotation process with aluminum electrodes could be a possible harvesting step at commercial scale for microalgal biomass production.

scholarly journals Sustainable Production of Monoraphidium Microalgae Biomass as a Source of Bioenergy

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5975
Author(s):  
Małgorzata Hawrot-Paw ◽  
Adam Koniuszy ◽  
Małgorzata Gałczyńska
Keyword(s):  
Phosphorus Content ◽  
Biomass Concentration ◽  
Biomass Productivity ◽  
Ash Content ◽  
Saline Wastewater ◽  
Microalgal Biomass ◽  
Recirculating Aquaculture ◽  
Microalgae Biomass ◽  
The Individual ◽  
Tubular Photobioreactors

Microalgae are a renewable source of unconventional biomass with potential application in the production of various biofuels. The production of carbon-neutral fuels is necessary for protecting the environment. This work determined the possibility of producing biomass of microalgae belonging to Monoraphidium genus using saline wastewater resulting from proecological salmon farming in the recirculating aquaculture system. The tests were carried out in tubular photobioreactors using LED light. As a part of the analyses, the growth and productivity of microalgal biomass, cell density in culture, and lipid concentration and ash content in biomass were determined. In addition, the concentration of selected phosphorus and nitrogen forms present in wastewater corresponding to the degree of their use by microalgae as a nutrient substrate was determined. The biomass concentration estimated in the tests was 3.79 g·L−1, while the maximum biomass productivity was 0.46 g·L−1·d−1. The cells’ optical density in culture measured at 680 nm was 0.648. The lipid content in biomass was 18.53% (dry basis), and the ash content was 32.34%. It was found that microalgae of the genus Monoraphidium effectively used the nitrogen as well as phosphorus forms present in the wastewater for their growth. The total nitrogen content in the sewage decreased by 82.62%, and total phosphorus content by over 99%. The analysis of the individual forms of nitrogen showed that N-NO3 was reduced by 85.37% and N-NO2 by 78.43%, while orthophosphate (V) dissolved in water was reduced by 99%. However, the content of N-NH4 in wastewater from the beginning till the end of the experiment remained <0.05 mg·L−1.

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