Arthrospira platensis as a Feasible Feedstock for Bioethanol Production
Open accessAbstract
In recent decades and to deal with the scarcity of fossil fuels, many studies have been developed in order to set up a sustainable biofuel production sector. This new sector must be efficient (high productivity), economically profitable (low production costs and therefore acceptable fuel prices), and ethical (low carbon balance, no competition with food resources). The production of bioethanol is based on the fermentation of reserve sugars, accumulated in the form of starch in microalgae and glycogen in cyanobacteria. The advantage of this bioenergy production route lies in the fact that the post-crop fermentation process is at the industrial stage since it has already been tested for many years for the production of bioethanol from agricultural resources. One of the most cultivated cyanobacteria is Arthrospira (“Spirulina”) and its production is also already at industrial scale. Depending on the cultivation conditions, this cyanobacteria is able to accumulate up to 65% DW (dry weight) of glycogen, making it a feasible feedstock for bioethanol production. The aim of this review is to provide a clear overview of these operating conditions for glycogen accumulation.
AI snapshot
Written from the paper’s full text.
TL;DR
This review argues that *Arthrospira platensis* is a feasible bioethanol feedstock because it can accumulate glycogen up to 65% DW (abstract; up to 70% DW in the introduction) under stress, and its glycogen-to-ethanol route resembles starch-based first-generation fermentation. It aggregates cultivation conditions—light, nitrogen/phosphorus/sulfur depletion, salinity, and combined stresses—that enhance glycogen, while noting biomass-cost and biomass-loss trade-offs.
Key findings
- High light promotes glycogen: at >200 μmol photons m⁻² s⁻¹, accumulation is about 45% DW (42–65% DW depending on study), versus below 20% DW at lower irradiances. Aikawa et al. reached 50% DW at 700 μmol photons m⁻² s⁻¹, and high light plus nitrogen depletion reached over 65% DW, compared with 18% DW for the control and 45% DW for nitrogen depletion alone.
- Nitrogen depletion raises glycogen/carbohydrates: Hasunuma et al. reported glycogen increasing to 63.2% DW while protein decreased to 15.4% under nitrate absence; Depraetere et al. reported total carbohydrates rising from 14% to 74% DW and protein falling from 37% to 10% DW. Aikawa et al. showed complete nitrogen starvation was not required, as 3 mM nitrate stimulated glycogen accumulation.
- Phosphorus and sulfur limitation can enhance glycogen without necessarily reducing biomass: phosphorus starvation reached up to 30% DW after 18 h (Klanchui et al.), 15.1 to 28.9% DW (Monshupanee and Incharoensakdi), and a 300% carbohydrate increase when phosphate was halved from 0.5 to 0.25 g/L (El-Shouny et al.). A 50% K₂SO₄ reduction enhanced carbohydrate production by 25%, a 100% reduction by 380%, and SO₄²⁻ depletion increased glycogen yield 300% after 24 h, reaching 60% DW after 96 h.
- Salinity and combined stresses also increase carbohydrates: NaCl from 1 to 40 g/L positively affected carbohydrate and lipid contents; nitrogen starvation plus 15% CO₂ increased total carbohydrate content by 61.5%, and nitrogen starvation plus 0.5 M NaCl increased it by 228.6%, reaching 58% DW. Techno-economically, Spirulina dry biomass cost was estimated at 5.1 USD kg⁻¹ for a plant producing 750,000 kg year⁻¹, higher than corn or sugarcane, but advantages include high growth rate, non-arable land use, CO₂ capture, mature cultivation, and co-product extraction.
Methods
- Review article; no primary experimental data. It synthesizes published studies on *A. platensis* growth requirements and environmental stresses for glycogen accumulation, including light intensity, nitrogen, phosphorus, sulfur, salinity, and combined stresses.
- Main analysis is narrative comparison of reported glycogen/carbohydrate contents, biomass effects, and culture conditions, plus techno-economic considerations comparing bioethanol process routes and feedstock costs.
Limitations
- Stated: studies are difficult to compare because of different cultivation conditions, strains, and glycogen quantification methods; some studies quantify only total carbohydrates, not specifically glycogen, and total carbohydrates can include EPS, trehalose, and glucosyl-glycerol.
- Stated: stress effects on glycogen accumulation are scarcely studied, and combined-stress studies are scarce; nutrient depletion can reduce biomass production, so two-stage cultivation is often required to first produce biomass and then induce glycogen.
- Stated/evident: biomass production costs are high (Spirulina dry biomass estimated at 5.1 USD kg⁻¹), and techno-economic evaluation is complicated by variations in process design and assumptions; evident from the text, the review does not describe a systematic search or quality-assessment protocol.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
0 of 56 cited sources checked · 0 supported · 0 flagged
- Interpretationreasoning
A. platensis is a feasible feedstock for bioethanol production.
“making it a feasible feedstock for bioethanol production.”
Quote in the paperSubstantial claim - Premisecitation
A. platensis can accumulate glycogen to high levels (up to 65-70% DW) depending on cultivation conditions.
“Depending on the cultivation conditions, this cyanobacteria is able to accumulate up to 65% DW (dry weight) of glycogen, making it a feasible feedstock for bioethanol production.”
- Also stated in: § 1. Introduction · plain
“This energy-store polysaccharide is mainly formed in Arthrospira platensis as a response of nutrient-stressed conditions, and accumulated (up to 70% DW) in granules in the thylakoid membranes [29][30][31].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [29][30][31]
Not checked in the free run.
- Also stated in: § 1. Introduction · plain
- Premisecitation
Glycogen can be degraded via enzymatic hydrolysis (saccharification) and fermented into bioethanol.
“This polysaccharide can be degraded via enzymatic hydrolysis (saccharification) and fermented into bioethanol [28].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [28] Monshupanee, 2014, Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803, J. Appl. Microbiol. source
Not checked in the free run.
- Interpretationreasoning
The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why A. platensis achieves similar biomass productivity under N-limited as under N-replete conditions despite impaired photosynthetic energy production.
“The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why Arthrospira is able to achieve a similar biomass productivity under N-limited as under Nreplete conditions, despite the fact that photosynthetic energy production was impaired by N-limitation.”
Quote in the paperNot a substantial claim - Premisecitation
Under nitrogen starvation, the flow of photosynthetically fixed carbon is diverted from protein synthesis to carbohydrates or lipids.
“Under nitrogen starvation, the flow of the photosynthetically fixed carbon is diverted from the protein synthesis metabolic pathway to carbohydrates or lipids [57].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [57] Chentir, 2018, Induced change in Arthrospira sp. (Spirulina) intracellular and extracellular metabolites using multifactor stress combination approach, J. Appl. Phycol. source
Not checked in the free run.
- Premisecitation
In presence of nitrate, glycogen and protein contents of Arthrospira remained nearly constant at ~15% DW and ~50% DW, respectively.
“In the presence of nitrate, the glycogen and protein contents remained nearly constant at ~15% DW and ~50% DW, respectively.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [64] Hasunuma, 2013, Dynamic metabolic profiling of cyanobacterial glycogen biosynthesis under conditions of nitrate depletion, J. Exp. Bot. source
Not checked in the free run.
- Interpretationnone given
Different modifications in culture medium and culture conditions of A. platensis can enhance glycogen production.
“Different modifications in culture medium and culture conditions of Arthrospira platensis can enhance glycogen production.”
Quote in the paperSubstantial claim - Premisecitation
Yoshikawa et al. observed a positive correlation of glycogen content with increasing light intensity, reaching 42% DW at 250 μmol photons m−2 s−1.
“They observed a positive correlation of the glycogen content with the increasing light intensity, reaching 42% DW for 250 μmol photons m 2 s -1 .”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [59] Yoshikawa, K., Aikawa, S., Kojima, Y., Toya, Y., Furusawa, C., Kondo, A., and Shimizu, H. (2015). Construction of a Genome-Scale Metabolic Model of Arthrospira platensis NIES-39 and Metabolic Design for Cyanobacterial Bioproduction. PLoS ONE, 10. source
Not checked in the free run.
- Premisecitation
Some studies have reached 60% DW glycogen under N-limitation.
“The proportion of carbohydrates in Arthrospira platensis cells can reach up to 50% dry weight (DW) by optimizing the cultivation conditions [17]; some studies have even reached 60% DW of glycogen under the N-limitation condition [31].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [31] Yao, 2016, Utilization of recovered nitrogen from hydrothermal carbonization process by Arthrospira platensis, Bioresour. Technol. source
Not checked in the free run.
- Premisecitation
El-Shouny et al. increased total carbohydrates of A. platensis by 300% when phosphate concentration was half-reduced from 0.5 g/L to 0.25 g/L.
“Another interesting result was obtained by El-Shouny et al. [66], who increased the total carbohydrates of Arthrospira platensis by 300%, when the phosphate concentration was half-reduced during the culture (from 0.5 g/L to 0.25 g/L).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [66] Sharaf, 2015, Production enhancement of some valuable compounds of Arthrospira platensis, J. Bas. E Environ. Sci.
Not checked in the free run.
- Premisecitation
If the concentration of inorganic phosphorus is low, glycogen synthesis is stimulated.
“If the concentration of inorganic phosphorus is low, the synthesis of glycogen is stimulated, as shown by [32], in phosphorus starvation conditions.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [32] Markou, 2012, Alteration of the biomass composition of Arthrospira (Spirulina) platensis under various amounts of limited phosphorus, Bioresour. Technol. source
Not checked in the free run.
- Premisecitation
At 700 μmol photons m−2 s−1, glycogen reached up to 50% DW.
“However, for higher light intensity (700 μmol photons m -2 s -1 ), the amount of glycogen reached up to 50% of cell dry weight.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [61] Aikawa, 2012, Synergistic enhancement of glycogen production in Arthrospira platensis by optimization of light intensity and nitrate supply, Bioresour. Technol. source
Not checked in the free run.
- Premisecitation
Shifting cyanobacterial cells into nitrogen depletion and cultivating for 72 h resulted in global metabolic modifications involving reductions in free amino acids (aspartate, glutamate, glutamine) and increases in organic acids (2-ketoglutarate, malate, succinate).
“Analyzing the metabolic intermediates, they observed that shifting the cyanobacterial cells into nitrogen depletion and cultivating them for 72 h resulted in global metabolic modifications that involved reductions in the levels of several free amino acids (aspartate, glutamate, and glutamine), and increased in the levels of organic acids (2-ketoglutarate, malate, and succinate).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [64] Hasunuma, 2013, Dynamic metabolic profiling of cyanobacterial glycogen biosynthesis under conditions of nitrate depletion, J. Exp. Bot. source
Not checked in the free run.
- Interpretationown data
The decrease in EPS/glycogen ratio with increasing light suggests a redirection of carbon flux toward glycogen.
“This decrease in EPS/glycogen ratio can thus suggest a redirection of the carbon flux toward glycogen while increasing the light.”
Quote in the paperNot a substantial claim - Interpretationreasoning
This approach would increase the overall yield of bioethanol production.
“Therefore, this approach would increase the overall yield of the bioethanol production.”
Quote in the paperSubstantial claim - Premisecitation
At four irradiances (100, 400, 800, and 1200 μmol photons m−2 s−1), EPS/glycogen ratios were 3.1, 1.79, 1.54, and 0.64, respectively.
“Additionally, as light intensity was found to be a key parameter for glycogen and EPS modulation, these authors also performed experiments at four irradiances (100, 400, 800, and 1200 μmol photons m -2 s -1 ) and calculated EPS/glycogen ratios, established respectively at 3.1, 1.79, 1.54, and 0.64.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [56] Thouand, 2019, Characterization of the polysaccharides chemical diversity of the cyanobacteria Arthrospira platensis, Algal Res. source
Not checked in the free run.
- Premisenone given
Under stress conditions, carbon flow is diverted from protein synthesis to lipids, carbohydrates, and carotenoids to ensure cell viability.
“In these conditions, the carbon flow is diverted from protein synthesis to lipids, carbohydrates, and carotenoids, among other metabolic pathways to ensure cell viability.”
Quote in the paperSubstantial claim - Premisecitation
Glycogen is mainly formed in A. platensis as a response to nutrient-stressed conditions.
“This energy-store polysaccharide is mainly formed in Arthrospira platensis as a response of nutrient-stressed conditions, and accumulated (up to 70% DW) in granules in the thylakoid membranes [29][30][31].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [29][30][31]
Not checked in the free run.
- Premisecitation
Phelippe et al. meta-bibliographic analysis showed an increase in glycogen content with light intensity.
“In 2019, Phelippe et al. [56] performed a meta-bibliographic analysis focused on glycogen and EPS production by Arthrospira, showing an increase in glycogen content with light intensity.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [56] Thouand, 2019, Characterization of the polysaccharides chemical diversity of the cyanobacteria Arthrospira platensis, Algal Res. source
Not checked in the free run.
- Premisecitation
The effect of different stress factors on glycogen accumulation is scarcely studied, despite their high added value for biofuel production.
“The effect of different stress factors on glycogen accumulation is scarcely studied, despite their high added value for biofuel production [57].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [57] Chentir, 2018, Induced change in Arthrospira sp. (Spirulina) intracellular and extracellular metabolites using multifactor stress combination approach, J. Appl. Phycol. source
Not checked in the free run.
- Premisecitation
Time-course profiling demonstrated transient increases in levels of other amino acids (glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, threonine, tyrosine).
“Time-course profiling of metabolites demonstrated transient increases in the levels of other amino acids (glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, threonine, and tyrosine).”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [64] Hasunuma, 2013, Dynamic metabolic profiling of cyanobacterial glycogen biosynthesis under conditions of nitrate depletion, J. Exp. Bot. source
Not checked in the free run.
- Premisecitation
Arias et al. observed with mixed cyanobacterial cultures that glycogen accumulation was enhanced, obtaining up to 47% of total carbohydrate content.
“This has also been observed by Arias et al. [72] with mixed cyanobacterial cultures, for which the glycogen accumulation was enhanced, obtaining up to 47% of total carbohydrate content.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [72] Arias, 2018, Polymer accumulation in mixed cyanobacterial cultures selected under the feast and famine strategy, Algal Res. source
Not checked in the free run.
- Premisecitation
The proportion of carbohydrates in A. platensis cells can reach up to 50% DW by optimizing cultivation conditions.
“The proportion of carbohydrates in Arthrospira platensis cells can reach up to 50% dry weight (DW) by optimizing the cultivation conditions [17]; some studies have even reached 60% DW of glycogen under the N-limitation condition [31].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [17] Rubio, 2021, Dietary exposure to trace elements (B, Ba, Li, Ni, Sr, and V) and toxic metals (Al, Cd, and Pb) from the consumption of commercial preparations of Spirulina platensis, Environ. Sci. Pollut. Res. Int. source
Not checked in the free run.
- Interpretationcitation
Reduction of phosphorous to enhance glycogen content of A. platensis seems like a good strategy, assuring both high glycogen content and biomass production.
“In summary, the reduction of phosphorous to enhance the glycogen content of Arthrospira platensis seems like a good strategy, assuring both high glycogen content and biomass production.”
Quote in the paperSubstantial claim - Premisecitation
Combining high light intensity and nitrogen depletion allowed Arthrospira platensis to reach over 65% DW, compared with 18% DW for the control and 45% DW for nitrogen depletion only.
“Aikawa et al. [61] proposed combining high light intensity and nitrogen depletion, allowing them to reach over 65% DW, whereas it was only 18% DW for the control and 45% DW for nitrogen depletion only.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Aikawa et al. [61] Aikawa, 2012, Synergistic enhancement of glycogen production in Arthrospira platensis by optimization of light intensity and nitrate supply, Bioresour. Technol. source
Not checked in the free run.
- Premisecitation
Ding et al. observed an increase in the total carbohydrate content of Arthrospira platensis of 61.5% using nitrogen starvation and a high level of CO2 (15% of CO2).
“Ding et al. [26] observed an increase in the total carbohydrate content of Arthrospira platensis of 61.5% using nitrogen starvation and a high level of CO2 (15% of CO2)”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Ding et al. [26] Ding, 2017, Three-stage gaseous biofuel production combining dark hydrogen, photo hydrogen, and methane fermentation using wet Arthrospira platensis cultivated under high CO2 and sodium stress, Energy Convers. Manag. source
Not checked in the free run.
- Interpretationreasoning
In most cases, two-stage cultivation is required to first produce a sufficient amount of biomass and then further induce glycogen accumulation.
“in most cases, two stage cultivation is required in order to first produce a sufficient amount of biomass, and then further induce glycogen accumulation.”
Quote in the paperSubstantial claim - Interpretationreasoning
Maintenance of cell growth is important to improve glycogen production for cyanobacteria as a biofuel feedstock.
“However, for the utilization of cyanobacteria as a biofuel feedstock, maintenance of cell growth is also important to improve glycogen production”
Quote in the paperSubstantial claim - Premisecitation
There is evidence that this modification of the metabolism can enhance glycogen production.
“as there is evidence pointing that this modification of the metabolism can enhance glycogen production [77].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [77] Trewavas, 2002, Cyclic nucleotides: The current dilemma, Curr. Opin. Plant Biol. source
Not checked in the free run.
- Premisecitation
Ding et al. observed an increase of 228.6% in total carbohydrate content using nitrogen starvation and osmotic stress (0.5M NaCl), reaching 58% DW total carbohydrate content compared to the control without CO2 nor NaCl.
“as well as an increase of 228.6% using nitrogen starvation and osmotic stress (0.5M of NaCl) reaching 58% DW of total carbohydrate content compared to the control without CO2 nor NaCl.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Ding et al. [26] Ding, 2017, Three-stage gaseous biofuel production combining dark hydrogen, photo hydrogen, and methane fermentation using wet Arthrospira platensis cultivated under high CO2 and sodium stress, Energy Convers. Manag. source
Not checked in the free run.
- Premisecitation
El-Shouny et al. demonstrated that reducing sulfur concentration in media significantly modified A. platensis carbohydrate accumulation without affecting growth or biomass productivity.
“El-Shouny et al. [66] also demonstrated that reducing the sulfur concentration in media significantly modified Arthrospira platensis carbohydrate accumulation without affecting the growth or biomass productivity.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [66] Sharaf, 2015, Production enhancement of some valuable compounds of Arthrospira platensis, J. Bas. E Environ. Sci.
Not checked in the free run.
- Interpretationreasoning
The main drawback of nutrient depletion is the reduction in biomass production.
“the main drawback is the reduction in the biomass production.”
Quote in the paperSubstantial claim - Premisecitation
Increased osmotic stress can induce Arthrospira cells to synthesize osmoprotectants (trehalose, glucosyl-glycerol, and glucosyl-glycerate).
“An increase in osmotic stress can induce Arthrospira cells to synthesize osmoprotectants (trehalose, glucosyl-glycerol, and glucosyl-glycerate) [76]”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [76] Carrieri, 2011, Contribution of a sodium ion gradient to energy conservation during fermentation in the cyanobacterium Arthrospira (Spirulina) maxima CS-328, Appl. Environ. Microbiol. source
Not checked in the free run.
- Premisecitation
Increases in sodium concentration are a strategy to accumulate carbohydrates, especially glycogen, in Arthrospira platensis.
“Increases in sodium concentration have been commonly observed in the literature as a strategy to accumulate carbohydrates in Arthrospira platensis, especially glycogen [26].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [26] Ding, 2017, Three-stage gaseous biofuel production combining dark hydrogen, photo hydrogen, and methane fermentation using wet Arthrospira platensis cultivated under high CO2 and sodium stress, Energy Convers. Manag. source
Not checked in the free run.
- Interpretationcitation
Increase in glycogen can have a beneficial side effect.
“The increase in glycogen in Arthrospira platensis can have a beneficial side effect”
Quote in the paperNot a substantial claim - Interpretationcitation
Different stresses can enhance the glycogen content of Arthrospira biomass.
“Different stresses can allow for the glycogen content of Arthrospira biomass to be enhanced.”
Quote in the paperSubstantial claim - Interpretationcitation
Arthrospira feedstock price appears much greater than corn or sugarcane.
“This feedstock price appears then to be much greater than corn or sugar-cane”
Quote in the paperSubstantial claim - Premisecitation
Accumulation of glycogen in Arthrospira platensis is accompanied by an increase in cellular density and sedimentation of the biomass.
“the accumulation of glycogen is accompanied by an increase in the cellular density and sedimentation of the biomass [63].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [63] Liu, 2019, Production and structural characterization of a new type of polysaccharide from nitrogen-limited Arthrospira platensis cultivated in outdoor industrial-scale open raceway ponds, Biotechnol. Biofuels source
Not checked in the free run.
- Premisecitation
NaCl from 1 up to 40 g/L exerts a positive effect on both the carbohydrate and lipid contents of Arthrospira platensis.
“Chentir et al. [57] found that the NaCl (from 1 up to 40 g/L) exerted a positive effect on both the carbohydrate and lipid contents of Arthrospira platensis.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites Chentir et al. [57] Chentir, 2018, Induced change in Arthrospira sp. (Spirulina) intracellular and extracellular metabolites using multifactor stress combination approach, J. Appl. Phycol. source
Not checked in the free run.
- Interpretationcitation
Increased cellular density and sedimentation facilitate downstream processing of biomass at industrial scale.
“This can be of great interest while producing glycogen at an industrial scale as it will facilitate downstream processing of the biomass.”
Quote in the paperSubstantial claim - Premisecitation
Addition of NaCl in the culture medium could affect the transcriptional regulation of the metabolism of different cyanobacteria via cAMP as a signaling molecule.
“The addition of NaCl in the culture medium could also affect the transcriptional regulation of the metabolism of different cyanobacteria via cAMP as a signaling molecule [59]”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [59] Yoshikawa, K., Aikawa, S., Kojima, Y., Toya, Y., Furusawa, C., Kondo, A., and Shimizu, H. (2015). Construction of a Genome-Scale Metabolic Model of Arthrospira platensis NIES-39 and Metabolic Design for Cyanobacterial Bioproduction. PLoS ONE, 10. source
Not checked in the free run.
- Premisecitation
Lipids and protein productivities were decreased as sulfur concentration decreased by half (40% and 44%, respectively).
“However, lipids and protein productivities were decreased as sulfur concentration decreased by half (40% and 44%, respectively), meaning that the modification in the concentration of sulfur can be oriented depending on the final product of interest.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [66] Sharaf, 2015, Production enhancement of some valuable compounds of Arthrospira platensis, J. Bas. E Environ. Sci.
Not checked in the free run.
- Premisecitation
Production costs of Spirulina dry biomass are estimated at 5.1 USD kg-1 assuming a plant with a productivity of 750,000 kg year-1.
“In a recent review, [82] estimated the production costs of Spirulina dry biomass at 5.1 USD kg -1 assuming a plant with a productivity of 750,000 kg year -1 .”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [82] Costa, 2019, Operational and economic aspects of Spirulina-based biorefinery, Bioresour. Technol. source
Not checked in the free run.
- May combine two claims. 27
- Classified as probably not a substantial claim. 14
May combine two claims.
PremisecitationA. platensis is suitable for biofuel production (3rd generation) due to its fast growth, all year cultivation, and chemical composition (44.4% carbohydrates, 45% proteins, and 10% lipids and ashes).
“Nevertheless, this microorganism is also suitable for biofuel production (3rd generation) due to its fast growth, all year cultivation, and chemical composition (44.4% carbohydrates, 45% proteins, and 10% lipids and ashes) [19][20][21].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [19][20][21]
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationArthrospira platensis is commercialized in at least 22 countries and represents about 60% of the global microalgal biomass production.
“Arthrospira platensis is commercialized in at least 22 countries and represents about 60% of the global microalgal biomass production [5].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [5] Lima, 2018, Influence of spectral light quality on the pigment concentrations and biomass productivity of Arthrospira platensis, Algal Res. source
Not checked in the free run.
May combine two claims.
PremisecitationAt 50 and 270 μmol photons m−2 s−1, glycogen content of A. platensis increased from 18% to 40% DW after 12 h and decreased to initial contents after three days.
“Regarding the glycogen accumulation, a similar tendency was observed at 50 and 270 μmol photons m -2 s -1 as glycogen content increased from 18% to 40% of cell dry weight after 12 h and decreased to the initial contents after three days.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [61] Aikawa, 2012, Synergistic enhancement of glycogen production in Arthrospira platensis by optimization of light intensity and nitrate supply, Bioresour. Technol. source
Not checked in the free run.
May combine two claims.
PremisecitationDuring exponential phase, A. platensis growth focuses on protein production and diverts maximum carbon and energy into cell growth and reproduction; during stationary phase (nutrient starvation) or under stress, glycogen is accumulated.
“The growth of Arthrospira platensis during the exponential phase is focused in protein production and diverts maximum carbon and energy into cell growth and reproduction, although, during the stationary phase (nutrient starvation) or under different stress conditions, glycogen is accumulated [56].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [56] Thouand, 2019, Characterization of the polysaccharides chemical diversity of the cyanobacteria Arthrospira platensis, Algal Res. source
Not checked in the free run.
May combine two claims.
PremisecitationKumaresan et al. observed downregulated genes in amino acid biosynthesis, protein folding, and rRNA binding, whereas genes involved in carbohydrate metabolism, DNA repair, among others, were upregulated during sulfur-stress conditions.
“Kumaresan et al. [74] analyzed the transcriptome profile of different genes involved in various sulfur-dependent pathways in Arthrospira sp and observed downregulated genes in amino acid biosynthesis, protein folding, and rRNA binding, whereas genes involved in carbohydrate metabolism, DNA repair, among others, were upregulated during sulfur-stress conditions.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [74] Kumaresan, 2017, Transcriptome changes of blue-green algae, Arthrospira sp. in response to sulfate stress, Algal Res. source
Not checked in the free run.
May combine two claims.
PremisecitationMonshupanee and Incharoensakdi found that total glycogen content increased from 15.1 to 28.9% DW under phosphorus deprivation, with biomass production not compromised.
“Another example of the enhancement in the production of glycogen via phosphorus deprivation is in Monshupanee and Incharoensakdi [28], where the total glycogen content increased from 15.1 to 28.9% DW.”
- Also stated in: § 3.3. Phosphorous Depletion · plain
“Nevertheless, the biomass production was not compromised.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [28] Monshupanee, 2014, Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803, J. Appl. Microbiol. source
Not checked in the free run.
- Also stated in: § 3.3. Phosphorous Depletion · plain
May combine two claims.
PremisecitationTranscriptomic and proteomic analysis indicated that N-limited condition induced downregulation of de novo protein synthesis, downregulation of photosynthetic energy production and carbon fixation, and upregulation of glycogen synthesis.
“Transcriptomic and proteomic analysis indicated that the N-limited condition induced a downregulation of de novo protein synthesis.”
- Also stated in: § 3.2. Nitrogen Depletion · plain
“In addition, photosynthetic energy production and carbon fixation were both downregulated, while glycogen synthesis was upregulated.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [29] Depraetere, O., Deschoenmaeker, F., Badri, H., Foubert, I., Leys, N., Wattiez, R., and Muylaert, K. (2015). Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches. PLoS ONE, 10. source
Not checked in the free run.
- Also stated in: § 3.2. Nitrogen Depletion · plain
May combine two claims.
PremisecitationDepraetere et al. observed an increase in total carbohydrates from 14% DW to 74% DW and a decrease in protein content from 37% DW to 10% DW under N-limited conditions.
“In another study, Depraetere et al. [29] observed an increase in total carbohydrates (from 14% DW to 74% DW) and a decrease in protein content (from 37% DW to 10% DW).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [29] Depraetere, O., Deschoenmaeker, F., Badri, H., Foubert, I., Leys, N., Wattiez, R., and Muylaert, K. (2015). Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches. PLoS ONE, 10. source
Not checked in the free run.
May combine two claims.
PremisecitationSulfur is an essential element for amino acids, lipid biosynthesis, and whole metabolism, and different concentrations can modify metabolism of cyanobacteria and production of glycogen and other bioactive molecules.
“Sulfur is known to be an essential element for amino acids, lipid biosynthesis, and the whole metabolism in general, where there is evidence that different concentrations of this element can modify the metabolism of cyanobacteria and its production of glycogen and other bioactive molecules [73].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [73] Cheng, 2014, Assessment of environmental stresses for enhanced microalgal biofuel production–an overview, Front. Energy Res. source
Not checked in the free run.
May combine two claims.
PremisecitationIn absence of nitrate, glycogen content increased to 63.2% DW while protein content decreased to 15.4%.
“In contrast, in the absence of nitrate, the glycogen content increased to 63.2% DW while the protein content decreased to 15.4%.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [64] Hasunuma, 2013, Dynamic metabolic profiling of cyanobacterial glycogen biosynthesis under conditions of nitrate depletion, J. Exp. Bot. source
Not checked in the free run.
May combine two claims.
PremisecitationUnder phosphorous starvation, compared with other starvation scenarios, there was no significant difference in biomass production compared to control, while glycogen production increased, reaching up to 30% DW after 18 h.
“In this case, comparing phosphorous starvation with the other scenarios, it did not present a significant difference in the biomass production compared to the control, while an increase in the production of glycogen was observed, reaching up to 30% DW of glycogen content after 18 h of culture.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [62] Klanchui, A., Dulsawat, S., Chaloemnegam, K., Cheevadhanarak, S., Prommeenate, P., and Meechai, A. (2018). An improved Genome-scale metabolic model of Arthrospira platensis C1 (iAK888) and its application in glycogen overproduction. Metabolites, 8. source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing).
Premisenone givenIn some studies, only total carbohydrates are quantified, and not specifically glycogen.
“Moreover, in some studies, only total carbohydrates are quantified, and not specifically glycogen.”
Quote in the paperNot a substantial claim- Rests on an assumption: Total carbohydrate measurements in some studies can be used as evidence for glycogen accumulation.
May combine two claims.
InterpretationcitationA limitation of nitrogen is sufficient to promote glycogen synthesis, opening the possibility of producing glycogen in continuous mode.
“This finding is of interest for industrial scale production, as a limitation is sufficient to promote the synthesis, thus opening the possibility of producing glycogen in continuous mode.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe proteins first degraded by A. platensis under nitrogen limitation seem to be the light-harvesting apparatus, phycobilisome, to provide nitrogen.
“As demonstrated for other cyanobacteria [70], the proteins first degraded by A. platensis seem to be their light-harvesting apparatus, phycobilisome, to provide nitrogen when exogenous nitrogen is limited.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [70] Grossman, 1993, Environmental effects on the light-harvesting complex of cyanobacteria, J. Bacteriol. source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationAlthough the precise role of glycogen in cyanobacteria remains unclear, it has been suggested that glycogen accumulation may be advantageous during starvation, providing stored energy and carbon surplus.
“Although the precise role that glycogen plays in cyanobacteria remains unclear, it has been suggested that the accumulation of glycogen by cyanobacteria may be advantageous during starvation periods, providing both a stored source of energy and a carbon surplus [69].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [69] Strange, 1968, Bacterial glycogen and survival, Nature source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisereasoningStudies on glycogen production in A. platensis are difficult to compare due to different cultivation conditions, strains used, and glycogen quantification methods.
“However, studies are sometimes difficult to compare, mainly due to the different cultivation conditions, strains used, and glycogen quantification methods.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationLow molecular weight carbohydrates (trehalose and glucosyl-glycerol) are found in A. platensis and are part of the total carbohydrates.
“Additionally, some low molecular weight carbohydrates (trehalose and glucosyl-glycerol) can be found [58] and are also part of the total carbohydrates.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [58] Hagemann, 2011, Compatible solute biosynthesis in cyanobacteria, Environ. Microbiol. source
Not checked in the free run.
May combine two claims.
PremisecitationGlycogen synthesis in A. platensis is strictly regulated by the amount of phosphorous in the cell, and ADP-glucose pyrophosphorylase is responsible for producing ADP-Glc, the glucosyl donor for elongation of α-1,4-glucosidic chain to synthesize glycogen.
“The glycogen synthesis in Arthrospira platensis is strictly regulated by the amount of phosphorous in the cell, and the enzyme ADP-glucose pyrophosphorylase is responsible for producing ADP-Glc, which is the glucosyl donor for the elongation of the α-1,4-glucosidic chain to synthesize glycogen [71].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [71] Ballicora, 2003, ADP-Glucose pyrophosphorylase, a regulatory enzyme for bacterial glycogen synthesis, MMBR source
Not checked in the free run.
May combine two claims.
PremisecitationNitrogen deficiency in culture media affects biomass production but significantly enhances production of energy-rich components like lipids and carbohydrates.
“The deficiency of nitrogen in the culture media affects biomass production but significantly enhances the production of energy-rich components like lipids and carbohydrates as a response to adverse conditions like starvation or environmental stress [69].”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [69] Strange, 1968, Bacterial glycogen and survival, Nature source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing).
InterpretationreasoningSuch transient increases might be caused by protein hydrolysis and subsequent assimilation of these amino acids into glycogen via gluconeogenesis.
“Such transient increases might be caused by protein hydrolysis and subsequent assimilation of these amino acids into glycogen via gluconeogenesis.”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
Premisenone givenA. platensis strains produce an exopolysaccharide (EPS) that remains bound to the cells and is supposed to protect cells from environmental stresses.
“Arthrospira strains also produce an exopolysaccharide (EPS), which remains bound to the cells and is supposed to protect cells from environmental stresses.”
Quote in the paperNot a substantial claimMay combine two claims.
PremisecitationA. platensis has a high carbon sequestration rate that can reach 0.92 g/L/d, making it a feasible biofuel feedstock.
“Its high carbon sequestration rate can reach 0.92 g/L/d, making it a feasible biofuel feedstock [22,23].”
Quote in the paperNot a substantial claim0 of 2 sources checked- cites [22] Sydney, 2010, Potential carbon dioxide fixation by industrially important microalgae, Bioresour. Technol. source
Not checked in the free run.
- cites [23] Choi, 2019, Microalgae Bioenergy with Carbon Capture and Storage (BECCS): An emerging sustainable bioprocess for reduced CO2 emission and biofuel production, Bioresour. Technol. Rep. source
Not checked in the free run.
May combine two claims.
PremisecitationComplete nitrogen starvation is not required for glycogen accumulation; 3 mM nitrate stimulated glycogen accumulation.
“Interestingly, Aikawa et al. [61] demonstrated that complete nitrogen starvation is not required, as glycogen accumulation was stimulated by using 3 mM of nitrate.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [61] Aikawa, 2012, Synergistic enhancement of glycogen production in Arthrospira platensis by optimization of light intensity and nitrate supply, Bioresour. Technol. source
Not checked in the free run.
Classified as probably not a substantial claim.
Interpretationnone givenDifferent strategies concerning the composition of culture media and culture conditions can enhance glycogen yields in Arthrospira platensis.
“Different strategies can be considered to enhance glycogen yields concerning the composition of the culture media and the culture conditions.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationProduction of ethanol through biological fermentation of sugars extracted from sugarcane or corn and wheat (1st generation biofuel) is technically mature and commercially available.
“Production of ethanol through biological fermentation of sugars extracted from sugarcane [78] or corn and wheat [79,80] (1st generation biofuel) is technically matured and commercially available.”
Quote in the paperNot a substantial claim0 of 3 sources checked- cites [78] Soccol, 2005, Brazilian biofuel program: An overview, J. Sci. Ind. Res.
Not checked in the free run.
- cites [79] Gulati, 1996, Assessment of ethanol production options for corn products, Bioresour. Technol. source
Not checked in the free run.
- cites [80] Mohanty, S.K., and Swain, M.R. (2019). Bioethanol production from corn and wheat: Food, fuel, and future. Bioethanol Prod. Food Crops, 45–59. source
Not checked in the free run.
May combine two claims.
InterpretationreasoningAccumulation of these low molecular weight carbohydrates increases the total amount of sugars, thereby enhancing bioethanol production.
“and the accumulation of these low molecular weight carbohydrates increases the total amount of sugars, thus enhancing the bioethanol production.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationIn A. platensis, one of the main solutes produced to mitigate osmotic pressure is trehalose, glucosyl-glycerol, and glucosyl-glycerate.
“In Arthrospira platensis, one of the main solutes produced to mitigate osmotic pressure is the production of trehalose, glucosyl-glycerol, and glucosyl-glycerate.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [58] Hagemann, 2011, Compatible solute biosynthesis in cyanobacteria, Environ. Microbiol. source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationHigh salt concentrations generate two major problems for living systems: low water potential results in loss of water accumulating osmotically-active compounds, and high ionic strength results in continuous influx of inorganic ions (mainly Na+ and Cl−).
“High salt concentrations generate two major problems for living systems: first, low water potential results in a loss of water accumulating osmotically-active compounds, and second, the high ionic strength of the surrounding medium results in a continuous influx of inorganic ions (mainly Na + and Cl -) [58].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [58] Hagemann, 2011, Compatible solute biosynthesis in cyanobacteria, Environ. Microbiol. source
Not checked in the free run.
May combine two claims.
PremisecitationA 50% reduction in K2SO4 enhanced carbohydrate production by 25%; further reduction of K2SO4 by 100% reached an enhancement of 380% compared to control (1 g/L K2SO4), while biomass concentrations did not represent a significant difference (134 and 136 mg/L/d).
“The reduction of 50% in K2SO4 enhanced carbohydrate production by 25%; interestingly, the further reduction of K2SO4 by 100%, reached an enhancement of 380% compared to the control (1 g/L of K2SO4), while the biomass concentrations did not represent a significative difference (134 and 136 mg L -1 d -1 , respectively).”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [66] Sharaf, 2015, Production enhancement of some valuable compounds of Arthrospira platensis, J. Bas. E Environ. Sci.
Not checked in the free run.
May combine two claims.
InterpretationreasoningConversion of glycogen into bioethanol would be close to a 1st generation process, and high cost pretreatments will not be required.
“As the glycogen is a polymer of glucose, just like starch, the conversion of glycogen into bioethanol would thus be closed to a 1st generation one from a process point of view, and high cost pre-treatments will not be required.”
Quote in the paperSubstantial claim- Rests on an assumption: Glycogen is a polymer of glucose, just like starch.
May combine two claims.
InterpretationreasoningArthrospira has high glycogen content in the biomass, leading to potentially better conversion yields.
“(5) the high glycogen content in the biomass (thus fermentescible sugars), thus leading to potentially better conversion yields;”
Quote in the paperSubstantial claimMay combine two claims.
PremisecitationKlanchui et al. analyzed depletion of NO3−, PO4−, and SO4− to obtain glycogen-enriched biomass of A. platensis; reduction in SO4− increased yield of glycogen production 300% compared to control after 24 h, but after 96 h amounts of glycogen were similar to NO3− depletion (60% DW).
“Klanchui et al. [60] analyzed the effect of depletion of NO 3-, PO4 3-, and SO4 2-to obtain a glycogen-enriched biomass of Arthrospira platensis, where it seems that the reduction in SO4 2-increased the yield of glycogen production 300% compared to the control after just 24 h of incubation, nevertheless, after 96 h of incubation, the amounts of glycogen obtained were similar to NO 3-depletion (60%”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [60] Li, 2008, Effects of nitrogen sources on cell growth and lipid accumulation of green alga Neochloris oleoabundans, Appl. Microbiol. Biotechnol. source
Not checked in the free run.
Probably not a substantial claim: may not pass S4 (based).
Interpretationnone givenNutrient depletion promotes glycogen levels in cells.
“Even if nutrient depletion promotes glycogen levels in the cells”
Quote in the paperNot a substantial claimProbably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.
PremisecitationCyanobacteria follow two strategies to mitigate osmotic pressure: pump out ions, especially Na+ and Cl−, and produce solutes compatible with cell metabolism.
“There are two strategies that cyanobacteria follow to mitigate the osmotic pressure: first, to pump out ions, especially Na + and Cl -, and second, to produce solutes that are compatible with the cell metabolism [75].”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [75] Hincha, 2004, Stabilization of model membranes during drying by compatible solutes involved in the stress tolerance of plants and microorganisms, Biochem. J. source
Not checked in the free run.
May combine two claims.
InterpretationcitationSulfur depletion seems similar to phosphate strategy, enhancing glycogen production without reducing biomass, so combination of both strategies could be a new approach in designing new culture media to obtain glycogen-enriched biomass.
“Analyzing the sulfur depletion, it seems similar to the phosphate strategy, which is the enhancement of glycogen production without reducing the amount of biomass produced during the culture, so the combination of both strategies could be a new approach in designing new culture media to obtain a glycogen-enriched biomass of Arthrospira platensis.”
Quote in the paperSubstantial claim
The paper relies on this without support.
The post-crop fermentation process for bioethanol production is at industrial stage, having been tested for many years for agricultural resources.
“The advantage of this bioenergy production route lies in the fact that the post-crop fermentation process is at the industrial stage since it has already been tested for many years for the production of bioethanol from agricultural resources.”
The paper relies on this without support.
Total carbohydrate measurements in some studies can be used as evidence for glycogen accumulation.
“Moreover, in some studies, only total carbohydrates are quantified, and not specifically glycogen.”
The paper relies on this without support.
Different Arthrospira/Limnospira strains and genera can be treated together for conclusions about glycogen accumulation and bioethanol feedstock.
“However, this paper will not discriminate between these genus as it is not possible to clearly compare previous works with one or the other.”
The paper relies on this without support.
First-generation bioethanol feedstock competes with food.
“However, this feedstock is competing with food, making it controversial.”
The paper relies on this without support.
Lignocellulosic biofuel technology is still under development and it is difficult to reach high ethanol concentrations during fermentation.
“but the technology is still under development as it is still difficult to reach high ethanol concentrations during fermentation.”
The paper relies on this without support.
The main limitation in industrial development of lignocellulosic biofuel processes is production costs linked to their complexity.
“the main limitation in the industrial development of such processes remains the production costs linked to their complexity.”
The paper relies on this without support.
Arthrospira has a high growth rate and volumetric productivity, with a very short harvesting cycle and production nearly all year.
“(1) the high growth rate and volumetric productivity as it has a very short harvesting cycle and a production that goes nearly all year (whereas higher plants have generally a one year growth cycle);”
The paper relies on this without support.
Arthrospira can grow on salt or wastewater streams, reducing freshwater use.
“(2) being able to grow on salt or wastewater streams thereby reducing freshwater use;”
The paper relies on this without support.
Arthrospira does not compete with arable land for food production.
“(3) not competing with arable land for food production;”
The paper relies on this without support.
Arthrospira captures CO2 via photosynthesis, mitigating greenhouse gas emissions.
“(4) CO2 capture via photosynthesis, thereby mitigating greenhouse gas emissions;”
The paper relies on this without support.
Mass cultivation and industrial plants for Arthrospira are already implemented, so the technology is already mature.
“(6) mass cultivation and industrial plants are already implemented, thus the technology is already mature;”
The paper relies on this without support.
Other compounds such as phycocyanin can be extracted prior to bioethanol production, allowing an increase in value and reduced production costs.
“(7) other compounds can be extracted prior to bioethanol production such as phycocyanin, allowing for an increase in value and reduce production costs.”
The paper relies on this without support.
Glycogen is a polymer of glucose, just like starch.
“As the glycogen is a polymer of glucose, just like starch”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Klanchui et al. is cited as reference 60, which lists different authors
MinorThe text attributes the depletion experiment to Klanchui et al. [60], but reference 60 is by Li et al. and concerns a green alga. Klanchui et al. instead appears as reference 62.
“Klanchui et al. [60] analyzed the effect of depletion of NO 3-, PO4 3-, and SO4 2-to obtain a glycogen-enriched biomass of Arthrospira platensis”
“60. Li, Y.; Horsman, M.; Wang, B.; Wu, N.; Lan, C.Q. Effects of nitrogen sources on cell growth and lipid accumulation of green alga Neochloris oleoabundans.”
Conflicting stated maximum glycogen contents
MinorThe abstract says Arthrospira accumulates up to 65% dry weight of glycogen, while the introduction gives a maximum of 70% dry weight.
“this cyanobacteria is able to accumulate up to 65% DW (dry weight) of glycogen”
“accumulated (up to 70% DW) in granules in the thylakoid membranes”
The citation lists haven’t been fetched yet
References 76 · Cited by 22
Research works printed but not linked: 6
- Vonshak, A. (1997). Physiology, Cell-Biology and Biotechnology, Taylor & Francis.
- Jakubczak, 2020, Fluoride content in dietary supplements of spirulina (Arthrospira spp.) from conventional and organic cultivation, Fluoride, 5, 469
- Zarrouk, C. (1966). Contribution à l’étude d’une Cyanophycée: Influence de Divers Facteurs Physiques et Chimiques sur la Croissance et la Photosynthèse de Spirulina Maxima. [Ph.D. Thesis, Université de Paris].
- Richmond, A.E. (1988). Microalgaculture. CRC Critical Reviews in Biotechnology, CRC Press Inc.
- Iltis, 1968, Tolérance de salinité de Spirulina platensis (Gom.) Geitler, (Cyanophyta) dans les mares natronées du Kanem (Tchad), Cah ORSTOM Sér Hydrobiol., 2, 119
- Cornet, J.-F. (1992). Etude Cinétique et Energétique d’un Photobioréacteur. Etablissement d’un Modèle Structure. Applications à un Ecosystème clos Artificiel. [Ph.D. Thesis, Université de Paris].
- Authors
- Gonzalez Bautista, E., & Laroche, C.
- Affiliations
- Institute Pascal, UMR CNRS 6602, University Clermont Auvergne, F-63000 Clermont-Ferrand, France
- Centre National de la Recherche Scientifique (FR)
- Corresponding author
- Laroche, Céline
- ORCID
- Laroche, Céline
- Venue
- Applied Sciences
- Publisher
- MDPI AG
- Published
- 2021-07-22
- Volume
- 11
- Issue
- 15
- Pages
- 6756
- ISSN
- 2076-3417 (ISSN-L)
- OpenAlex
- W3186282225
- Semantic Scholar
- 5bbbc2f0f8b8097360f77c82c2181d8720b6c7ac
- Cited by
- 22
- References
- 76
- Citations by year
- 2026: 2 · 2025: 4 · 2024: 6 · 2023: 6 · 2022: 4
- FWCI
- 0.75
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Applied Sciences (publishedVersion, cc-by)
- HAL (submittedVersion, cc-by)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
- Funders
- Région Auvergne-Rhône-Alpes (CPER MMaSyF)
- Topics
- Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
- Physical Sciences › Engineering › Biomedical Engineering › Biofuel production and bioconversion
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Microbial Metabolic Engineering and Bioproduction
- Keywords
- Spirulina platensis, Spirulina, bioethanol production, cyanobacteria, glycogen accumulation, fermentation, biofuels, growth conditions, starch
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-07.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-07.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
