Maximum Cell Concentration Research Articles

English

In response to the environmental problems caused by plastics of petrochemical origin, a reduction in the use of these materials and their replacement by biodegradable polymers have been sought. Polyhydroxybutyrate (PHB), a biopolymer of biological origin that belongs to the polyhydroxyalkanoates (PHAs), is similar to polypropylene in terms of its mechanical properties, thermodegradability and melting temperature. Various microorganisms, including cyanobacteria, can synthesize this biopolymer. The objective of this study was to stimulate biopolymer synthesis by Spirulina sp. LEB 18 that was grown under different nutritional conditions. Initially, the growth was conducted with Spirulina sp. LEB 18 without the adaptation of the inoculum. In these assays, the concentrations of the carbon, nitrogen and phosphorus sources were varied. The assay that showed the maximum concentration of biopolymers was reproduced with the adaptation of the inoculum for 45 days. There was an inverse relationship between the cell growth and biopolymer synthesis. The assay that contained 0.25 g L-1 sodium nitrate, 4.4 g L-1 sodium bicarbonate and 0.5 g L-1 potassium phosphate showed the maximum cell concentration (0.6 g L-1) and a low biopolymer accumulation (13.4%). In addition, the assay that contained 0.05 g L-1 sodium nitrate, 8.4 g L-1 sodium bicarbonate and 0.5 g L-1 potassium phosphate produced a high biopolymer concentration (30.7%) and a low cell concentration (0.5 g L-1). The adaptation of the inoculum increased the cell concentration by 7.0% and the biopolymer yield by 20.5%. The biopolymer production was more efficient in assays in which the nitrogen was restricted and had maximum carbon consumption. Key words: Biopolymers, polyhydroxyalkanoates, microalgae, cyanobacteria.

GROWTH AND COMPOSITION OF Arthrospira (Spirulina) platensis IN A TUBULAR PHOTOBIOREACTOR USING AMMONIUM NITRATE AS THE NITROGEN SOURCE IN A FED-BATCH PROCESS

NH4NO3 simultaneously provides a readily assimilable nitrogen source (ammonia) and a reserve of nitrogen (nitrate), allowing for an increase in Arthrospira platensis biomass production while reducing the cost of the cultivation medium. In this study, a 22plus star central composite experimental design combined with response surface methodology was employed to analyze the influence of light intensity (I) and the total amount of added NH4NO3 (Mt) on a bench-scale tubular photobioreactor for fed-batch cultures. The maximum cell concentration (Xm), cell productivity (PX) and biomass yield on nitrogen (YX/N) were evaluated, as were the protein and lipid contents. Under optimized conditions (I = 148 μmol·photons·m-2·s-1 and Mt = 9.7 mM NH4NO3), Xm = 4710 ±34.4 mg·L-1, PX = 478.9 ±3.8 mg·L-1·d-1 and YX/N = 15.87 ±0.13 mg·mg-1 were obtained. The best conditions for protein content in the biomass (63.2%) were not the same as those that maximized cell growth (I = 180 μmol·photons·m-2·s-1 and Mt = 22.5 mM NH4NO3). Based on these results, it is possible to conclude that ammonium nitrate is an interesting alternate nitrogen source for the cultivation of A. platensisin a fed-batch process and could be used for other photosynthetic microorganisms.

PRODUCTION OF DOCOSAHEXAENOIC ACID (DHA) FROM Thraustochytrium sp. ATCC 26185 USING DIFFERENTS NITROGEN CONCENTRATIONS

Polyunsaturated fatty acids (PUFAs) of the type ω3 and ω6 play important physiological functions in human organism, since they are components of cell membranes and brain cells; they decrease the levels of triglycerides and can prevent the incidence of coronary heart disease. Various parameters, including concentration of the nitrogen source in the cultivation of oleaginous microorganisms have been reported to be essential in the biosynthesis and accumulation of PUFAs. The objective of this work is to study the effect of different concentrations of total nitrogen (TN) in the production of PUFAs, especially DHA, from Thraustochytrium sp. ATCC 26185. The concentrations of TN evaluated were 2.4 and 0.8 g/L (batch) and 0.009 g/L (hourly) under fed-batch process. The content of cell biomass, glucose consumption, TN and production of PUFAs was determined. The major composition of the PUFAs in Thraustochytrium sp. ATCC 26185 cell biomass were DPA ω6 (21-25%) and DHA (69-73%), regardless of the type and time of culture. The maximum cell concentration obtained (30.2 g/L) was using 2.4 g/L TN in 168 h of culture. With this same concentration of TN it was possible to produce the highest concentration of DHA (1.16 g/L) in 120 h of culture, demonstrating that the growth of Thraustochytrium sp. ATCC 26185 and yield of PUFAs are dependent on the concentration TN source available for consumption of this oleaginous microorganism, as well as culture time.

Ferric sulfate coagulation and powdered activated carbon adsorption as simultaneous treatment to reuse the medium in Arthrospira platensis cultivation

AbstractBACKGROUNDCyanobacteriae and microalgae industries require large amounts of water for their cultivation. Reusing the Arthrospira platensis culture medium is scarcely evaluated in the literature. This work evaluates coagulation and adsorption as a simultaneous process to treat A. platensis spent medium by applying different concentrations of powdered activated carbon (PAC) and ferric sulfate (S) and by using different contact times (T) to remove organic matter and pigments.RESULTSThe process efficiency was measured by removal of both organic matter and pigments by absorbance at 254 and 440 nm, respectively. The highest maximum cell concentration (4863 ± 64 mg L−1) and protein content values (60.0 ± 0.6%) were observed in a medium treated with optimal conditions using PAC = 40.0 mg L−1, S = 32.8 mg L−1 and T = 36.1 min. Under such conditions, chlorophyll‐a biomass content of 24.5 ± 0.6 mg g dry cell−1 and chlorophyll‐a productivity of 16.8 ± 0.1 mg L−1 d−1 were obtained.CONCLUSIONSCoagulation and adsorption as a simultaneus treatment allowing reuse of the spent medium of A. platensis cultivation can diminish not only its production costs but also environmental pollution. The biomass produced in the treated medium contains more protein and chlorophyll than that produced in the standard medium. © 2015 Society of Chemical Industry

Ferric chloride flocculation plus carbon adsorption allows to reuse spent culture medium of Arthrospira platensis

Arthrospira platensis cultivation produces a saline spent medium that must be treated to allow its reuse, thus saving water and avoiding environmental pollution. This study evaluates the association of flocculation followed by adsorption to treat the spent medium by applying different concentrations of granular activated carbon (GAC) and ferric chloride (F), and using different residence times (T). The simultaneous optimization of the independent variables GAC, F, and T was performed using both a 23 central composite design and a response surface methodology. The cells cultivated in the medium obtained after the optimal conditions of treatment (GAC = 54.2 g L−1, F = 10.0 mg L−1, and T = 30.8 min) provided the highest maximum cell concentration, Xm = 3140 ± 77 mg L−1 in 0.5 L Erlenmeyer flasks with the highest protein biomass content (44.9%). The treated medium in such conditions was also used in a 3.5 L tubular photobioreactor (PBR), reaching Xm = 4033 ± 110 mg L−1 and biomass with high contents of both protein (47.3 ± 2.6%) and chlorophyll (9.7 ± 0.3 mg g dry cell−1). Therefore, this study can contribute to diminishing costs of A. platensis production by reusing its culture medium and improving its biomass quality in PBRs.

Proof of Concept: Containment Systems that Prevent Freeze-Dryer Contamination When Lyophilizing Escherichia coli (JM 109)

This study describes the use of containment systems to prevent escape of microorganisms during lyophilization, thereby avoiding contamination of freeze-drying equipment. Cultures of Escherichia coli (JM 109) of an approximate cell concentration of 109 cfu/mL were suspended in 0.9% saline, aseptically dispensed into vials, double-wrapped in either medical-grade paper or Tyvek sterilization pouches and freeze-dried. An intentional collapse phenomenon was observed during the freeze-drying process, ejecting debris and aerosols from the vials, thus representing a worst-case challenge for containment. Following freeze drying, the layers of the pouches were tested for microbial contamination using 3 M Clean-Trace surface ATP analyzer swabs, surface swabs, and tryptone soya agar contact plates. The paper and Tyvek pouches were able to contain a maximum cell concentration of 1 × 106 cfu/mL of E. coli recovered from ejected debris. Some penetration through the first paper pouch layer was observed (although not Tyvek); however, this was successfully retained by the second, outer layer preventing contamination of the lyophilization apparatus and laboratory environment.

Effects of Nitrogen‐Doped Multiwall Carbon Nanotubes on Murine Fibroblasts

The effect of nitrogen‐doped multiwall carbon nanotubes (CNx) on the proliferation of NIH‐3T3 murine fibroblasts is presented. CNTs were dispersed in distillated water and incubated with mammalian cells in order to evaluate their toxicity. Also, the influence of factors such as dosage (7 and 70 µg/mL), exposure time (24 to 96 h), and the exposure route (before and after cell liftoff) on the cell proliferation was evaluated. When the CNx were simultaneously incubated with the cells, the control culture reached a maximum cell concentration of 1.3 × 105 ± 3.4 × 104 cells per well at 96 h, whereas cultures with 7 µg/mL reached a concentration of 2.6 × 104 ± 5.3 × 103 cells. In the case of 70 µg/mL of CNx most of the cells were dead. The CNx that were added 24 h after cell dissociation showed that live cells decreased, with a cell concentration of 9.6 × 104 ± 9 × 103 for 7 µg/mL and 5.5 × 104 ± 9.5 × 103 for 70 µg/mL, in contrast to control cultures with 1.1 × 106 ± 1.5 × 104. The results showed that the CNx had cytotoxic effects depending on the concentration and exposure route.

A split airlift bioreactor for continuous culture of Glycyrrhiza inflata cell suspensions

In this study, we established a perfusion split airlift bioreactor coupled with a cell retention device (CRD) and tested for the production of Glycyrrhiza inflata cell suspension cultures. The main components of the CRD were two steel membrane filters and a bidirectional-pump. The results indicated that cells could effectively be separated from the medium by using 200-μm-pore membrane filters. When the bioreactor was operational, liquid was rotated in both the reaction column and the CRD. The frequency with which the direction of liquid circulation changed in the CRD was a key factor for ensuring that the membrane was clean and the filter remained unclogged. This was achieved even at high cell densities, when the direction of liquid circulation in the CRD changed every 5 min. Nevertheless, liquid circulation mode in the reaction column was disturbed to some extent by the fast rotation of the bidirectional-pump, which worked against mass transfer and cell growth. Under appropriate conditions the bioreactor system operated smoothly and the maximum cell concentration of 27.2 g L−1 dry weight was attained.

Use of acetate in fed-batch mixotrophic cultivation of Arthrospira platensis

Arthrospira platensis has been photoautotrophically cultivated for the production of high quality biomass. It contains satisfactory contents of protein, pigments, and fatty acids. The use of organic compounds as a carbon source has been studied, aiming to improve the biomass productivity in a mixotrophic process. In this study, A. platensis was cultivated by fed-batch process with the addition of sodium acetate, evaluating the effect of different concentrations and feeding time of this organic carbon source by the use of response surface methodology. Addition of sodium acetate was shown to be suitable for increasing the maximum cell concentration. The optimum condition was estimated by the model to be achieved with 387 mg L−1d−1 of sodium acetate for 6.5 days. Employing this condition, average Xm of 1769 ± 71 mg L−1 was achieved. This Xm value had an increase of almost 39 % in comparison with the standard cultivation, without acetate addition (1275 mg L−1).

Cultivation of the benthic microalga Prorocentrum lima for the production of diarrhetic shellfish poisoning toxins in a vertical flat photobioreactor

In this study, the cultivation conditions of Prorocentrumlima, including temperature, nutrient concentration, photoperiod, and salinity were observed, and then an effective method for the large-volume cultivation of P. lima using a vertical flat photobioreactor was developed for the first time. The maximum cell concentrations and toxin contents of P. lima cultured in the photobioreactor were reached after a 35days cultivation. Moreover, a step-wise double-sedimentation centrifugation method was used to harvest the microalgae cells, with the harvest rate of 89%. Toxin analysis of dry microalgal powder indicated that OA and DTX1 contents were 15.2 and 21.6mgg−1, respectively. These results verify that the culture method using the proposed photobioreactor is effective to massively produce DSP toxin-containing P. lima. This study may serve as a guide for the large-scale production of toxin-producing red-tide benthic microalgae.

Effects of temperature on the astaxanthin productivity and light harvesting characteristics of the green alga Haematococcus pluvialis

The green alga Haematococcus pluvialis, which accumulates astaxanthin at an optimal temperature of 20°C, was cultivated under temperatures of 20°C, 23.5°C, 27°C, and 30.5°C, in order to assess the effects on algal metabolism during the growth phase. The culture growth rate declined with above-optimal increases in temperature, and the final maximum cell concentration at 30.5°C reached only 35% of that attained at 20°C. On the contrary, the biomass productivity was increased under all the high-temperature conditions, probably reflecting the metabolism switch from cell duplication to energy accumulation that is typically observed in algal cultures subjected to environmental stress. Moreover, an increase in the light-harvesting capability of the alga was observed by means of the total pigment balance and the photosynthesis-intensity (PI) curve measured under the different cultivation conditions. Cultures kept at higher temperatures were able to better harvest and utilize the impinging light due to photo-acclimation. Finally, the differences in the astaxanthin metabolism were elucidated by subjecting the cultures to nitrogen starvation at 20°C and 27°C. In the culture at 27°C, a 1.4-fold increase in the astaxanthin productivity was observed when compared to that at 20°C, and the latter required almost two-fold more energy for the astaxanthin production compared with the 27°C culture.

Increasing efficiency of human mesenchymal stromal cell culture by optimization of microcarrier concentration and design of medium feed

Background aimsLarge amounts of human mesenchymal stromal cells (MSCs) are needed for clinical cellular therapy. In a previous publication, we described a microcarrier-based process for expansion of MSCs. The present study optimized this process by selecting suitable basal media, microcarrier concentration and feeding regime to achieve higher cell yields and more efficient medium utilization. MethodsMSCs were expanded in stirred cultures on Cytodex 3 microcarriers with media containing 10% fetal bovine serum. Process optimization was carried out in spinner flasks. A 2-L bioreactor with an automated feeding system was used to validate the optimized parameters explored in spinner flask cultures. ResultsMinimum essential medium-α–based medium supported faster MSC growth on microcarriers than did Dulbecco's modified Eagle's medium (doubling time, 31.6 ± 1.4 vs 42 ± 1.7 h) and shortened the process time. At microcarrier concentration of 8 mg/mL, a high cell concentration of 1.08 × 106 cells/mL with confluent cell concentration of 4.7 × 104cells/cm2 was achieved. Instead of 50% medium exchange every 2 days, we have designed a full medium feed that is based on glucose consumption rate. The optimal medium feed that consisted of 1.5 g/L glucose supported MSC growth to full confluency while achieving the low medium usage efficiency of 3.29 mL/106cells. Finally, a controlled bioreactor with the optimized parameters achieved maximal confluent cell concentration with 16-fold expansion and a further improved medium usage efficiency of 1.68 mL/106cells. ConclusionsWe have optimized the microcarrier-based platform for expansion of MSCs that generated high cell yields in a more efficient and cost-effective manner. This study highlighted the critical parameters in the optimization of MSC production process.

Control of tyramine and histamine accumulation by lactic acid bacteria using bacteriocin forming lactococci

The aim of this study was to evaluate the competitive effects of three bacteriocin producing strains of Lactococcus lactis subsp. lactis against two aminobiogenic lactic acid bacteria, i.e. the tyramine producing strain Enterococcus faecalis EF37 and the histamine producing strain Streptococcus thermophilus PRI60, inoculated at different initial concentrations (from 2 to 6logcfu/ml). The results showed that the three L. lactis subsp. lactis strains were able to produce bacteriocins: in particular, L. lactis subsp. lactis VR84 and EG46 produced, respectively, nisin Z and lacticin 481, while for the strains CG27 the bacteriocin has not been yet identified, even if its peptidic nature has been demonstrated. The co-culture of E. faecalis EF37 in combination with lactococci significantly reduced the growth potential of this aminobiogenic strain, both in terms of growth rate and maximum cell concentration, depending on the initial inoculum level of E. faecalis. Tyramine accumulation was strongly reduced when E. faecalis EF37 was inoculated at 2logcfu/ml and, to a lesser extent, at 3logcfu/ml, as a result of a lower cell load of the aminobiogenic strain. All the lactococci were more efficient in inhibiting streptococci in comparison with E. faecalis EF37; in particular, L. lactis subsp. lactis VR84 induced the death of S. thermophilus PRI60 and allowed the detection of histamine traces only at higher streptococci inoculum levels (5–6logcfu/ml). The other two lactococcal strains did not show a lethal action against S. thermophilus PRI60, but were able to reduce its growth extent and histamine accumulation, even if L. lactis subsp. lactis EG46 was less effective when the initial streptococci concentration was 5 and 6logcfu/ml. This preliminary study has clarified some aspects regarding the ratio between bacteriocinogenic strains and aminobiogenic strains with respect to the possibility to accumulate BA and has also showed that different bacteriocins can have different effects on BA production on the same strain. This knowledge is essentially aimed to use bacteriocinogenic lactococci as a predictable strategy against aminobiogenic bacteria present in cheese or other fermented foods.

Effect of soil extracts concentration on specific growth rate and lipid content of chlorella vulgaris in bolds basal medium

Effective nutrient medium is the key factor that significantly influences the specific growth rate and the final concentration of microalgae. The main objective of this study was to optimize the microalgal growth in mass culture system under the effect of soil extract in modified Bolds Basal medium. Chlorella vulgaris was grown aseptically for 10 days at five different concentrations of soil extract (10, 20, 30, 40, 50ml/L) at 25°C cultivation temperature. After 10 days of cultivation, Chlorella vulgaris showed maximum cell concentration of 5x107/ml at 30ml/L of soil extract concentration which corresponds to the maximum specific growth rate 1.56μd-1 with the doubling rate of 2.25d-1 andlipid yield of 22.74 % of dry weight.________________________________________GRAPHICAL ABSTRACT

Urea increases fed‐batch growth and γ‐linolenic acid production of nutritionally valuable Arthrospira (Spirulina) platensis cyanobacterium

In this article we investigate the simultaneous influence of feeding time and amount of urea added as a nitrogen source on the fed‐batch growth and composition of Arthrospira (Spirulina) platensis. Cultivations were performed in 5‐L minitanks at constant temperature (25°C) and light intensity (42 μmol photons/m2s), using exponentially increasing rate of urea addition, and varying the above independent variables in the ranges 9–15 days and 4.6–12.1 mM, respectively. Special emphasis was placed on the content of added high value fatty acids (e.g., γ‐linolenic acid) of concern for the food industry. To this purpose, a 22‐plus star central composite design was employed, and maximum cell concentration, cell productivity, yield of biomass on nitrogen added, protein content and fatty acids profile were evaluated by multiple regression analysis. The highest cell concentration (1759 mg/L) was obtained at feeding time of 14 days and amount of urea per unit reactor volume of 5.8 mM, while the highest contents of γ‐linolenic acid (27.5% of the lipid fraction) and proteins (77.2%) were obtained at 10 and 14 days and 5.8 and 10.8 mM, respectively. The results confirm the possibility of using urea as cheap nitrogen source to culture this nutritionally valuable cyanobacterium.

PRODUCTION OF DOCOSAHEXAENOIC ACID (DHA) FROM Thraustochytrium sp. ATCC 26185 USING DIFFERENTS NITROGEN CONCENTRATIONS

In this work it was studied the polyunsaturated fatty acids (PUFAs) production, especially DHA, from Thraustochytrium sp. ATCC 26185, under different total nitrogen (TN) availability. Three different TN conditions were evaluated: two with initial concentrations of 2.4 g/L and 0.8 g/L, and the third in a fed-batch process with a rate of 0.009 g/L.h. For each experiment the biomass, glucose, TN and PUFAs were determined. The major composition of the PUFAs in Thraustochytrium sp. ATCC 26185 cell biomass were DPA ω6 (21-25 %) and DHA (69-73 %), regardless of the type and time of culture. The maximum cell concentration (30.2 g/L) was obtained using 2.4 g/L TN in 168 h of culture. With this same concentration of TN it was possible to produce the highest concentration of DHA (1.16 g/L) in 120 h of culture, demonstrating that the growth of Thraustochytrium sp. ATCC 26185 and yield of PUFAs are dependent on the source concentration of TN available for consumption of this oleaginous microorganism, as well as culture time.

Approach toward an efficient inoculum preparation stage for suspension BHK-21 cell culture.

Mammalian cells are the most frequently used hosts for biopharmaceutical proteins manufacturing. Inoculum quality is a key element for establishing an efficient bioconversion process. The main objective in inoculation expansion process is to generate large volume of viable cells in the shortest time. The aim of this paper was to optimize the inoculum preparation stage of baby hamster kidney (BHK)-21 cells for suspension cultures in benchtop bioreactors, by means of a combination of static and agitated culture systems. Critical parameters for static (liquid column height: 5, 10, 15mm) and agitated (working volume: 35, 50, 65mL, inoculum volume percentage: 10, 30% and agitation speed: 25, 60rpm) cultures were study in T-flask and spinner flask, respectively. The optimal liquid column height was 5mm for static culture. The maximum viable cell concentration in spinner flask cultures was reached with 50mL working volume and the inoculum volume percentage was not significant in the range under study (10-30%) at 25rpm agitation. Agitation speed at 60rpm did not change the main kinetic parameters with respect to those observed for 25rpm. These results allowed for a schedule to produce more than 4×10(9) BHK-21 cells from 4×10(6) cells in 13day with 1,051mL culture medium.

Temperature dependence of an estuarine harmful algal bloom: Resolving interannual variability in bloom dynamics using a degree day approach.

Observations of harmful algal blooms (HABs) of the dinoflagellate Alexandrium fundyense in an estuary over multiple years were used to assess drivers of their spatial and temporal variability. Nauset Estuary on Cape Cod, Massachusetts has a recurrent, self-seeding A. fundyense population that produces paralytic shellfish poisoning toxins and leads to nearly annual closure to shellfishing. Weekly surveys of the entire estuary were made in 3 of 4 consecutive years, with surveys of a subembayment during the intervening year. Major A. fundyense blooms were observed all 4 years, with maximum concentrations >106 cells L-1. Concentrations were greatest in three salt ponds at the distal edges of the estuary. The bloom timing varied among the salt ponds and among years, although the blooms had similar durations and maximum cell concentrations. Nutrient concentrations did not correlate with the growth of the bloom, but differences in water temperature among years and ponds were significant. Net growth rates inferred from the surveys were similar to those from laboratory experiments, and increased linearly with temperature. A growing degree day calculation was used to account for effects of interannual variability and spatial gradients in water temperature on population development. The approach collapsed variability in the timing of bloom onset, development, and termination across years and among ponds, suggesting that this relatively simple metric could be used as an early-warning indicator for HABs in Nauset and similar areas with localized, self-seeding blooms.

Kinetics and modeling of microalga Tetraselmis sp. FTC 209 growth with respect to its adaptation toward different trophic conditions

Biomass and lipid production of microalga, Tetraselmis sp. FTC 209, isolated from local coastal waters was evaluated for photoautotrophic, mixotrophic and heterotrophic metabolism. Four non-linear growth models (logistic, logistic with lag, modified Gompertz, Baranyi–Roberts) were assessed for prediction of culture performance. Using statistical criteria, the Baranyi–Roberts model was chosen to estimate the growth kinetics values. Walne's mariculture medium was redesigned based on the concept of elemental balance to support higher density photoautotrophic growth. Biomass capacity of at least 100% was fixed for all micronutrient components while a sequential increase of 10% was imposed on deficient macronutrients. Results indicate that the new medium (W-30) managed to achieve a maximum cell concentration (Xmax) of 1.505g/L and maximum lipid content (Pmax) of 376mg/L (∼25% of dry cell weight), representing 1.8 and 3.7-fold improvements, respectively, relative to Walne's basal. Light and dark cultivations with glucose supplementation revealed that Tetraselmis sp. FTC 209 favors mixotrophic over heterotrophic mode in terms of cell growth and lipid production. Compared with the baseline photoautotrophic W-30 medium, cultivation with addition of 30g/L glucose produced the highest Xmax at 8.08g dry cell weight/L. This effectively provides significant algal biomass and lipid productivity of 404mg dry cell weight/L per day and 90.9mg lipid/L per day, respectively.

Protein production in Spirulina platensis biomass using beet vinasse-supplemented culture media

Beet vinasse is a by-product from molasses fermentation factories, which is difficult to dispose of and involves a severe environmental concern. The present work deals with the valorisation of beet vinasse by means of the protein production in Spirulina platensis biomass. A preliminary study was firstly planned in batch flasks to analyse the influence of environmental factors on S. platensis protein content and protein productivity in beet vinasse supplemented culture media. Experimental conditions were selected to operate the photobioreactor that could provide a balance between protein content and cell growth. Then, S. platensis was cultured in an airlift tubular photobioreactor using mineral medium supplemented with beet vinasse (SVM media). The maximum cell concentration and protein productivity achieved in the tubular photobioreactor were 6.5±0.7gL−1 and 168±18mgL−1d−1, respectively (with SVM 1gL−1 of vinasse). The addition of a higher vinasse concentration (SVM 2gL−1) led to biomass concentration and protein productivity values (3.6±0.3gL−1 and 86±6mgL−1d−1, respectively) closer to those achieved using unsupplemented mineral medium. Stable biomass concentrations were maintained during the continuous operation, thus demonstrating the ability of S. platensis to adapt to these culture media.