Cultivation Of Chlorella Research Articles

A sequential procedure for the quantification of biologically produced polyphosphate in sediment samples

A sequential procedure for the quantification of biologically produced polyphosphate in sediment samples Polyphosphate (poly-P) is a phosphate storage compound widespread in prokaryotic and eukaryotic cells. Its quantification, however, is not yet well developed for sediment samples because of the difficulties associated with using a single extractant to extract a specifie P compound without altering others. The present work uses an analytical procedure already developed to measure poly-P in algal cultures and later modified here for sediments to study poly-P in the sediment. The procedure uses the Ethylenediaminetetraacetic aeid (EDTA) method for sequential P-fractionation. This approach ensures that the main inorganic phosphate compounds (Le., Fe- and Ca-bound phosphate) are extracted prior to poly-P quantification. We applied this method to suspensions likely to contain biologically produced poly-P, such as laboratory cultures of Synechocystis PCC 6803 (Cyanobacteriaceae), Anabaena variabilis (Cyanobacteriaceae), and Chlorella sp. (Chlorophyceae) growing in a P­enriched medium, and activated sludge. According to this procedure, the concentrations of poly-P in Synechocystis PCC 6803, Anabaena variabilis and Chlorella cultures were 15.4, 6.2 and 7.2 % of the sum of all P-fractions, respectively, whereas activated sludge showed a lower percentage (3.7 %). Known volumes of these suspensions and a commercially available synthetic poly-P standard (Trimetaphosphate) were added to natural sediment. The P-composition of each sample was then compared in duplicate to the corresponding control samples (sediment alone). Poly-P in all control sediment samples was extremely low (0-2 ~g g-l d.w.). It increased in all sediment suspensions to which biological samples had been added. The increase was particularly noteworthy for Synechocystis (up to 220 ~g g-l d.w. of poly-P). The recovery of poly-P in sediment samples to which Anabaena cultures had been added showed some deviation from al: 1 expected:observed ratio, particularly when 2 mi of the culture were added (ratio of 0.79). However, the recovery improved to 1.12: 1 when a larger volume was added (5 mi), probably owing to the inhomogeneous nature of the cyanobacteria culture. In contrast, the addition of 500 mg of trimetaphosphate to the control sediment did not significantly increase (p > 0.05) the percentage found for the observed poly-P fraction. Consequently, biologically produced poly-P can be associated with the fraction of poly-P extracted through use of this procedure.

Nitrogen and phosphorus removal through laboratory batch cultures of microalga Chlorella vulgaris and cyanobacterium Planktothrix isothrix grown as monoalgal and as co-cultures

Batch cultures of the green microalga Chlorella vulgaris and cyanobacterium Planktothrix isothrix and their corresponding co-cultures were grown in municipal wastewater in order to study their growth as well as the nitrogen (NH4–N) and phosphorus (PO43−–P) removal. The cultures were grown under two irradiances of 20 and 60 μmol photons m−2 s−1 in shaken and unshaken conditions. The co-culture of unshaken Chlorella and Planktothrix showed the greatest growth under both irradiances. The monoalgal Planktotrix cultures showed better growth when unshaken than when shaken, whereas Chlorella cultures grew better when mixed, but only at the higher irradiance. The highest percentage of nitrogen removal (up to 80%) was attained by the unshaken co-cultures of Chlorella and Planktothrix. The amount of nitrogen recycled in the biomass reached up to 85% of that removed. Shaken monoalgal cultures of Chlorella showed phosphorus removal under both irradiances. They completely removed the initial phosphorus concentration (7.47 ± 0.17 mg L−1) within 96 and 48 h under 20 and 60 μmol photons m−2 s−1, respectively.

Lumostatic strategy for microalgae cultivation utilizing image analysis and chlorophyll a content as design parameters

Cultivation of microalgae Chlorella sp. was performed in draft-tube photobioreactors. Effect of light intensity on the microalgae growth performance was conducted under a light intensity range of 82–590 μmol/m 2 s. A lumostatic strategy was proposed based on the light distribution profiles obtained by image analysis and specific chlorophyll a content. The proposed lumostatic strategy allowed a maximum biomass dry weight of 5.78 g/L and a productivity of 1.29 g/L d, which were 25.7% and 74.3% higher than that achieved by the optimal constant light intensity, respectively. A comparison with other lumostatic strategies reported in the literature indicated that the proposed lumostatic strategy in the current study can be a promising approach in improving the growth of microalgae.

Production of high-density Chlorella culture grown in fermenters

The freshwater microalga Chlorella vulgaris was grown heterotrophically in fed-batch 50–600-L fermenters at 36°C, on aerated and mixed nutrient solution with urea as a nitrogen and glucose as a carbon and energy source. Cell density increased from the initial value 6.25 to 117.18 g DW L−1 in 32 h in the fermenter 50 L at a mean growth rate 3.52 g DW L−1 h−1. The DW increase in the fermenter 200 L was from 7.25 to 94.82 g DW L−1 in 26.5 h at a mean growth rate 3.37 g DW L−1 h−1. Mean specific growth rate I¼ was about 0.1 h−1 in the both fermenters, if nutrients and oxygen were adequately supplied. The DW increase in the fermenter 600 L was from 0.8 to 81.6 g DW L−1 in 66.5 h at a mean growth rate 1.22 g DW L−1 h−1 and I¼â€‰= 0.07 h−1. A limitation of the cell growth rate in 600 L fermenter caused by a low dissolved oxygen concentration above cell densities higher than 10 g DW L−1) occurred. Specific growth rate decreased approximately linearly with increasing glucose concentration (25–80 g glucose L−1) at the beginning of cultivation and decreased with the time of cultivation. The cell yield was 0.55–0.69 g DW (g glucose)−1. The content of proteins, I²-carotene, and chlorophylls in the cells steadily increased and starch content decreased, by keeping aerated and mixed culture another 12 h in fermenter after the cell growth was stopped due to glucose deficiency.

STUDI KARAKTERISTIK FLUORESENSI CHLORELLA spp : PENGARUH pH TERHADAP PENGKULTURAN

: Experiments for measuring the fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser of energy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration range from 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationship with the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at the starting culture influenced the cell concentration.

Sequential dark–photo fermentation and autotrophic microalgal growth for high-yield and CO 2-free biohydrogen production

Dark fermentation, photo fermentation, and autotrophic microalgae cultivation were integrated to establish a high-yield and CO 2-free biohydrogen production system by using different feedstock. Among the four carbon sources examined, sucrose was the most effective for the sequential dark (with Clostridium butyricum CGS5) and photo (with Rhodopseudomonas palutris WP3-5) fermentation process. The sequential dark–photo fermentation was stably operated for nearly 80 days, giving a maximum H 2 yield of 11.61 mol H 2/mol sucrose and a H 2 production rate of 673.93 ml/h/l. The biogas produced from the sequential dark–photo fermentation (containing ca. 40.0% CO 2) was directly fed into a microalga culture ( Chlorella vulgaris C–C) cultivated at 30 °C under 60 μmol/m 2/s illumination. The CO 2 produced from the fermentation processes was completely consumed during the autotrophic growth of C. vulgaris C–C, resulting in a microalgal biomass concentration of 1999 mg/l composed mainly of 48.0% protein, 23.0% carbohydrate and 12.3% lipid.

In-field experimental verification of cultivation of microalgae Chlorella sp. using the flue gas from a cogeneration unit as a source of carbon dioxide

A complex treatment of agricultural waste including the following major steps: anaerobic fermentation of suitable waste, cogeneration of the obtained biogas and growth of microalgae consuming the CO(2) from biogas and flue gas was verified under field conditions in a pilot-scale photobioreactor. The growth kinetics of microalgae Chlorella sp. consuming mixture of air and carbon dioxide (2% (v/v) of CO(2)), or flue gas (8-10% (v/v) of CO(2)) was investigated. The results obtained in the pilot photobioreactor were compared with results previously measured in laboratory photobioreactors. The field tests were performed in a pilot-scale outdoor solar-bubbled photobioreactor located at a biogas station. The pilot-scale photobioreactor was in the shape of a flat and narrow vertical prism with a volume of 300 L. The microalgae growth rates were correlated with empirical formulas. Laboratory analyses of the produced microalgae confirmed that it meets the strict EU criteria for relevant contaminants level in foodstuffs. Utilization of flue gases from cogeneration therefore was not found to be detrimental to the quality of microalgal biomass, and may be used in these types of bioreactors.

Optimization of the influential factors for the improvement of CO 2 utilization efficiency and CO 2 mass transfer rate

Microalgae fix CO 2 as energy source and afford biomass and high valued products such as carotenoids, pigments, proteins, and vitamins that can be used for the production of nutraceuticals, pharmaceuticals, animal feed additives, cosmetics, etc. Carbon dioxide is the sole source of carbon and it is supplied continuously for the microalgal cultivation. But undissolved CO 2 is lost by outgassing and sufficient dissolved CO 2 should be provided to avoid carbon limitation. The effect of CO 2 mass transfer with different CO 2 concentrations, aeration rate of gas, bubble size, baffle type and baffle number on the growth of Chlorella sp. AG10002 was investigated and the optimized conditions for the enhancement of biomass productivity were determined. We confirm that these results can be provided as basic data to improve the CO 2 mass transfer ability for the high density culture of Chlorella sp. and some microalgae having commercial value.

Investigation of the Complex Influence of the Preparation Stomp E33(Pendimethalin) Over Daphnia Magna Straws (Dissolved in Water and Accumulated from Chlorella Kessleri)

ABSTRACTAn experiment with juvenile Daphnia magna, according to ISO 6341 (1996), in two repetitions, has been carried out. A toxicity criterion was the immobilization of D. magna.During the cultivation of D. magna, Chlorella kessleri was added in concentration 2.105 cell/ml. This number of cells was a starting point for the toxicological experiment.Two cultures of chlorella with a different density of the cells (the first one with 2 times higher number of cells than the second one) were treated for 24h with 40 mg/l pendimethalin (this is 24h EC50 for chlorella established in our experiments). A control experiment variant was put in a clean medium. Two basic variants were obtained using centrifugation of the algal suspension followed by resuspendation in the daphnia medium: the first one with final concentration 0, 4 mg/l, and second one with 0, 8 mg/l pendimethalin.Chlorella density of was 2.105 cells/ml in both cases. For more complete picture of the effect of the treated algal cultures on D. magna, each of the above mentioned variants was divided into four subvariants.It was concluded that the variants with algal suspension influenced from pendimethalin and those with influenced algae, resuspended in Daphnia medium, were the most toxic for D. magna

Enhanced Chlorella vulgaris Buitenzorg growth by photon flux density alteration in serial photobioreactors

Microalgae perform oxygenic photosynthesis and are capable of taking up a large amount of CO2, using an inducible CO2 concentrating mechanism (CCM), and fixing CO2 into higher compounds. These characteristics make the microalgae potentially useful for removal and utilization of CO2 emitted from industrial plants and, generally, the usage of photosynthetic microorganisms has increased and significantly improved as a solution for CO2 emissions. In this light and based on previous research using Anabaena cylindrica IAM M1 and Spirulina platensis IAM M 135, enhancement was sought for CO2 fixation and biomass production by Chlorella vulgaris Buitenzorg by increasing the photon flux density concurrent with increases in culture biomass during the cellular growth phase and was compared to cultures of Chlorella grown at optimal constant illumination, with all cultures grown using Bennick basal medium, 29°C, and a flow of 1.0 atm. 10% CO2 enriched air delivered to three in serial photobioreactors of 0.200 dm3 capacity each. The results showed that increasing illumination during culture increased biomass production of Chlorella by ∼60% as well as increased CO2 fixation ability by ∼7.0%. It was also demonstrated that the non-competitive inhibition of [HCO3−] as a carbon source significantly affected the cultivation in both the increasing and constant photon flux density regimes.

INVOLVEMENT OF INDOLE-3-ACETIC ACID PRODUCED BY THE GROWTH-PROMOTING BACTERIUM AZOSPIRILLUM SPP. IN PROMOTING GROWTH OF CHLORELLA VULGARIS(1).

Involvement of indole-3-acetic acid (IAA), produced by the microalgae-growth-promoting bacteria Azospirillum brasilens and A.lipoferum, in promoting growth of the microalga Chlorella vulgaris Beij. was studied. Four wildtype strains of Azospirillum and their IAA-deficient mutants were co-immobilized with C.vulgaris in alginate beads. Cultures were grown in synthetic growth medium supplemented with tryptophan. Growth promotion of microalgae and production of exogenous IAA by Azospirillum spp. were monitored. All wildtype Azospirillum spp. produced significant but varying amounts of IAA, while their mutant forms produced significantly less. The results demonstrated a significant growth promotion in Chlorella cultures when immobilized with the four wildtype strains of Azospirillum, while very low or no enhanced growth was induced by the four IAA-deficient mutants, compared to when C.vulgaris is immobilized alone. A complementation experiment, where an IAA-attenuated mutant (A.brasilense SpM7918) was supplemented with IAA produced by its parental wildtype strain (A.brasilense Sp6), restored growth promotion in the microalgae-mutant culture.

Feasibility of Using Microalgal Biomass Cultured in Domestic Wastewater for the Removal of Chromium Pollutants

The feasibility of obtaining and using the biomass of a microalga, Chlorella miniata, from domestic wastewater (DW) cultures for the removal of chromium(III) [Cr(III)] and chromium(VI) [Cr(VI)] was compared with that from commercial Bristol medium (BM). Results showed that Chlorella miniata cultured in DW under 16-8 hours light-dark cycle [DW(16-8)] had similar growth to that in BM [BM(16-8)], but these two biomass had different biochemical compositions, and the former one had lower carbohydrate and higher protein content. When cultured in domestic wastewater, a higher biomass was obtained under continuous illumination [DW(24-0)], and the cells had higher carbohydrate and lower protein concentrations than that of DW(16-8). The spectra of the Fourier transform infrared spectrometer revealed that the functional groups on the surface of the three kinds of biomass--DW(16-8), DW(24-0), and BM(16-8)--were comparable, except an additional peak at 1731 cm(-1) was found in the biomass cultured in domestic wastewater, which was probably the result of bacterial contamination. Although biochemical differences were found among the three kinds of microalgal biomass, similar biosorption performances to chromium pollutants were recorded, with approximately 75% Cr(III) and 100% Cr(VI) removed at equilibrium in Cr(III) and Cr(VI) experiments, respectively, when dead biomass was used as a biosorbent. Therefore, it is possible to culture Chlorella miniata in domestic wastewater and use the biomass for the removal of chromium pollutants.

Application of the Stover–Kincannon kinetic model to nitrogen removal by Chlorella vulgaris in a continuously operated immobilized photobioreactor system

AbstractBACKGROUND: The aim of this study was to evaluate the ammonium nitrogen removal performance of algae culture Chlorella vulgaris in a novel immobilized photobioreactor system under different operating conditions and to determine the biokinetic coefficients using the Stover–Kincannon model.RESULTS: The photobioreactor was continuously operated at different initial ammonium nitrogen concentrations (NH4‐N0 = 10–48 mg L−1), hydraulic retention times (HRT = 1.7–5.5 days) and nitrogen/phosphorus ratios (N/P = 4/1–13/1). Effluent NH4‐N concentrations varied between 2.1 ± 0.5 mg L−1 and 26 ± 1.2 mg L−1 with increasing initial NH4‐N concentrations from 10 ± 0.6 mg L−1 to 48 ± 1.8 mg L−1 at θH = 2.7 days. The maximum removal efficiency was obtained as 79 ± 4.5% at 10 mg L−1 NH4‐N concentration. Operating the system for longer HRT improved the effluent quality, and the percentage removal increased from 35 ± 2.4% to 93 ± 0.2% for 20 mg L−1 initial NH4‐N concentration. The N/P ratio had a substantial effect on removal and the optimum ratio was determined as N/P = 8/1. Saturation value constant, and maximum substrate utilization rate constant of the Stover–Kincannon model for ammonium nitrogen removal by C. vulgaris were determined as KB = 10.3 mg L−1 d−1, Umax = 13.0 mg L−1 day−1, respectively.CONCLUSION: Results indicated that the algae‐immobilized photobioreactor system had an effective nitrogen removal capacity when the operating conditions were optimized. The optimal conditions for the immobilized photobioreactor system used in this study can be summarized as HRT = 5.5 days, N/P = 8 and NH4‐N0 = 20 mg L−1 initial nitrogen concentration to obtain removal efficiency greater than 90%. Copyright © 2008 Society of Chemical Industry

Presence of previously undescribed bacterial taxa in non-axenic Chlorella cultures

We determined the bacterial community profile in non-axenic cultures of Chlorella (Chlorophyceae, Chlorophyta) isolated from soil. The bacterial composition at the phylum level was different from that of whole soil bacteria, but it was similar to that reported for non-axenic cultures of marine microalgae such as diatoms (Bacillariophyceae, Heterokontophyta). Expected novel bacteria, i.e. those which do not have close relatives among described species, were maintained in the cultures, and these bacteria were chiefly composed of members of the phylum Bacteroidetes. They may have been 'as-yet-uncultured' but in practice unintentionally been cultured in microalgal cultures. They could serve as good bioresources in various fields of biological and ecological studies.

Biodegradation of a Nigerian Crude Oil by a Micro Alga and a Cyanobacterium

This study investigated the ability of pure and co-cultures of the eukaryotic green microalga Chlorella and the Cyanobacterium, Chroococcus sp. (Anacystis) obtained from a freshwater system in the Niger Delta, to degrade a Nigerian crude (Bonny Light) in a batch system for a 28-day period. Biodegradation experiments were carried out using BGII medium with pH range of 6.0-7.7. At day 28 percentage primary biodegradation of Chlorella, Chroococcus , co-cultures, and control, were 64.8%, 67.69. 69.8% and 3.8% respectively. Percentage of total organic carbon lost in these systems at day 28 were 64.8%, 67.9%, 80.9% and 2.9% respectively. The percentage of hydrocarbon levels of these systems remaining at day 28 were 26.7%, 16.7% 10.0% and 97.5% respectively. These results showed that there was no significant difference (P>0.05) between percentage primary biodegradation, total organic carbon and crude oil losses between cultures of Chlorella, Chroococcus and co cultures of both organisms. Thus both organisms may be used separately in the bioaugumentation protocol for remediation of crude oil contaminated aquatic systems. The use of co-cultures of both organisms did not offer any significant (P>0.05) advantage over the use of pure cultures of both organisms. Keywords : eukaryotes, prokaryotes, pure cultures, co-cultures, cyanobacteria, algae. Tropical Freshwater Biology Vol. 16 (1) 2007: pp. 17-30

Reduction of CO 2 by a high-density culture of Chlorella sp. in a semicontinuous photobioreactor

The microalga incorporated photobioreactor is a highly efficient biological system for converting CO 2 into biomass. Using microalgal photobioreactor as CO 2 mitigation system is a practical approach for elimination of waste gas from the CO 2 emission. In this study, the marine microalga Chlorella sp. was cultured in a photobioreactor to assess biomass, lipid productivity and CO 2 reduction. We also determined the effects of cell density and CO 2 concentration on the growth of Chlorella sp. During an 8-day interval cultures in the semicontinuous cultivation, the specific growth rate and biomass of Chlorella sp. cultures in the conditions aerated 2–15% CO 2 were 0.58–0.66 d −1 and 0.76–0.87 g L −1, respectively. At CO 2 concentrations of 2%, 5%, 10% and 15%, the rate of CO 2 reduction was 0.261, 0.316, 0.466 and 0.573 g h −1, and efficiency of CO 2 removal was 58%, 27%, 20% and 16%, respectively. The efficiency of CO 2 removal was similar in the single photobioreactor and in the six-parallel photobioreactor. However, CO 2 reduction, production of biomass, and production of lipid were six times greater in the six-parallel photobioreactor than those in the single photobioreactor. In conclusion, inhibition of microalgal growth cultured in the system with high CO 2 (10–15%) aeration could be overcome via a high-density culture of microalgal inoculum that was adapted to 2% CO 2. Moreover, biological reduction of CO 2 in the established system could be parallely increased using the photobioreactor consisting of multiple units.

Modeling of lutein production by heterotrophic Chlorella in batch and fed-batch cultures

Chlorella is a promising alternative resource of lutein (xanthophyll) production as it can be cultivated heterotrophically in fermentors. In this paper, a kinetic model for lutein production by heterotrophic Chlorella pyrenoidosa was developed based on batch cultivations in 250-ml flasks and a 19-l fermentor. The model was validated by experimental data from two fed-batch cultivations performed in the same fermentor. The dynamic behavior of lutein production by C. pyrenoidosa with various concentrations of glucose and nitrogen was analyzed based on the kinetic model. Model-based analyses suggested that glucose concentrations between 5 and 24 g/l and nitrogen concentrations between 0.7 and 12 g/l during the cultivation were favorable for lutein production by heterotrophic C. pyrenoidosa. It also showed that fed-batch cultivations are more suitable for efficient production of lutein than batch ones. The results obtained in this study may contribute to commercial lutein production by heterotrophic Chlorella.

Optimization for high-density cultivation of heterotrophic Chlorella based on a hybrid neural network model

The purpose of this study was to develop a reliable hybrid neural network (HNN) model for heterotrophic growth of Chlorella, based on which optimization for fed-batch (FB) cultivation of Chlorella may be successfully realized. Deterministic kinetic model was preliminarily developed for the optimization of FB cultivation of Chlorella. The highest biomass concentration and the maximum productivity were obtained as: 104.9 g l(-1) dry cell weight and 0.613 g l(-1) h(-1), respectively. After several cultivations had been performed, an HNN model was developed. The efficiency of biomass production was further increased by the optimization using this model. The highest biomass concentration and the maximum productivity attained was: 116.2 g l(-1) dry cell weight and 1.020 g l(-1) h(-1), respectively. The HNN model agreed well with experimental results in different cultivations. Comparison between the HNN model and the deterministic model showed that the former had better generalization ability, which made it a reliable tool in modelling and optimization. The high cell density and productivity of biomass obtained in this study is of significance for the commercial cultivation of Chlorella. The simple and efficient optimization strategy proposed in this paper may be employed in heterotrophic mass culture of Chlorella as well as other similar organisms.

A study of the growth for the microalga Chlorella vulgaris by photo‐bio‐calorimetry and other on‐line and off‐line techniques

Calorimetry and other on-line techniques are used for the first time as complement to the traditional off-line methods in order to follow the growth of the green Chlorella vulgaris microalgae. A 2-L photo-bio-reactor was adapted from a commercial calorimeter used previously to study heterotrophic microbial growth. An external source of light was added to favor the photosynthesis of the autotrophic cells. Heterotrophic growth was also tested with external glucose in the broth. A third mode, mixotrophic, allowed faster autotrophic plus heterotrophic growth. Calorimetric measurements were performed considering the corresponding calibrations in order to consider only the energy involved during the microalgal growth. The three different modes of Chlorella cultures were energetically characterized. Besides calorimetry, the weight of diluted nitric acid added to maintain the pH of the culture was correlated with the cellular growth and the nitrogen composition of the algae. Additionally, the on-line infrared spectroscopy proved to be an efficient technique to follow the composition of the broth in glucose, nitrates, and phosphates. These results were compared and complemented with some classic off-line techniques used to track this kind of cultures.

Utilization of flue gas for cultivation of microalgae Chlorella sp.) in an outdoor open thin-layer photobioreactor

Flue gas generated by combustion of natural gas in a boiler was used for outdoor cultivation of Chlorella sp. in a 55 m2 culture area photobioreactor. A 6 mm thick layer of algal suspension continuously running down the inclined lanes of the bioreactor at 50 cm s−1 was exposed to sunlight. Flue gas containing 6–8% by volume of CO2 substituted for more costly pure CO2 as a source of carbon for autotrophic growth of algae. The degree of CO2 mitigation (flue gas decarbonization) in the algal suspension was 10–50% and decreased with increasing flue gas injection rate into the culture. A dissolved CO2 partial pressure (pCO2) higher than 0.1 kPa was maintained in the suspension at the end of the 50 m long culture area in order to prevent limitation of algal growth by CO2. NO X and CO gases (up to 45 mg m−3 NO X and 3 mg m−3 CO in flue gas) had no negative influence on the growth of the alga. On summer days the following daily net productivities of algae [g (dry weight) m−2] were attained in comparative parallel cultures: flue gas = 19.4–22.8; pure CO2 = 19.1–22.6. Net utilization (η) of the photosynthetically active radiant (PAR) energy was: flue gas = 5.58–6.94%; pure CO2 = 5.49–6.88%. The mass balance of CO2 obtained for the flue gas stream and for the algal suspension was included in a mathematical model, which permitted the calculation of optimum flue gas injection rate into the photobioreactor, dependent on the time course of irradiance and culture temperature. It was estimated that about 50% of flue gas decarbonization can be attained in the photobioreactor and 4.4 kg of CO2 is needed for production of 1 kg (dry weight) algal biomass. A scheme of a combined process of farm unit size is proposed; this includes anaerobic digestion of organic agricultural wastes, production and combustion of biogas, and utilization of flue gas for production of microalgal biomass, which could be used in animal feeds. A preliminary quantitative assessment of the microalgae production is presented.