Renewable energy from Cyanobacteria: energy production optimization by metabolic pathway engineering

Probably not a substantial claim: may not pass S3 (load-bearing).

Biofuel possesses lower energy content than fossil fuels.

“Furthermore, biofuel possesses lower energy content than fossil fuels.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Of the three biochemical fractions (carbohydrates, lipids, proteins), lipids have the highest energy content.

“Of these three biochemical fractions, lipids have the highest energy content.”

Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing).

Peak oil will be reached as early as 2014.

“Nashawi et al. (2010) predicted that peak oil will be reached as early as 2014.”

• cites Nashawi et al. (2010) sourceNot checked yet

  Not checked in the free run.

May combine two claims.

The genomes of 41 strains of cyanobacteria have already been sequenced, including strains amenable to genetic manipulation.

“The genomes of 41 strains of cyanobacteria have already been sequenced including strains that are amenable to genetic manipulation (http://www.ncbi.nlm.nih.gov/genomes/lproks.cgi).”

• cites http://www.ncbi.nlm.nih.gov/genomes/lproks.cgiNot checked yet

  Not checked in the free run.

May combine two claims.

Microalgae cultures do not compete with agriculture, requiring neither bio-productive lands nor freshwater.

“In addition to their higher yield per hectare, microalgae cultures do not compete with agriculture, requiring neither bio-productive lands nor freshwater (Chisti 2007, 2008; Griffiths and Harrison 2009; Mata et al. 2010, Rittmann 2008).”

• cites Chisti 2007 sourceNot checked yet

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• cites Chisti 2008 sourceNot checked yet

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• cites Griffiths and Harrison 2009Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Biofuel (either biodiesel or bioethanol) is currently the only alternative energy source able to replace transport fuel in today's vehicles without involving major modifications to vehicle engines.

“Biofuel (either biodiesel or bioethanol) is currently the only alternative energy source able to replace transport fuel in today’s vehicles without involving major modifications to vehicle engines (Kaygusuz 2009).”

• cites Kaygusuz 2009 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Cyanobacteria possess a relatively small genome and many have been completely sequenced, making system biology approaches less complicated than in eukaryotic algae.

“Cyanobacteria possess a relatively small genome and many of them have already been completely sequenced, thus it is also less complicated to perform system biology approaches in these organisms when compared to eukaryotic algae (Rittmann 2008).”

• cites Rittmann 2008 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Cyanobacteria have received less attention than other feedstocks such as microalgae or crops for production of lipid-based biofuels.

“For the production of lipid-based biofuels, cyanobacteria have received less attention than other feedstocks such as microalgae (Miao and Wu 2006; Rodolfi et al. 2009) or crops.”

• cites Miao and Wu 2006 sourceNot checked yet

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• cites Rodolfi et al. 2009 sourceNot checked yet

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May combine two claims.

Longer chain alcohols possess higher energy content and can be stored and transported easier than ethanol.

“The longer chain alcohols possess higher energy content and can be stored and transported easier than ethanol (Atsumi et al. 2008).”

• cites Atsumi et al. 2008 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Cyanobacteria have been applied as bioremediation agents to remove heavy metals from aquatic ecosystems and reduce excess phosphate and nitrate in farmlands.

“Moreover, cyanobacteria have been applied as bioremediation agents to remove heavy metals from aquatic ecosystems and reduce the excess of phosphate and nitrate in farmlands (Hall et al. 1995; Ono and Cuello 2007).”

• cites Hall et al. 1995 sourceNot checked yet

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• cites Ono and Cuello 2007 sourceNot checked yet

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May combine two claims.

Citramalate synthase occurs in cyanobacteria, generating the possibility to produce propanol and butanol from 2-ketobutyrate.

“A very recent discovery that citramalate synthase occurs in cyanobacteria generates the possibility to produce propanol and butanol from 2-ketobutyrate, as this compound is an intermediate in the biosynthesis of citramalate (Wu et al. 2010).”

• cites Wu et al. 2010Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

At least 14 genera of cyanobacteria are capable of producing H2.

“Several reports have reviewed cyanobacterial species capable of producing H2 (Abed et al. 2009; Das and Veziroglu 2001; Dutta et al. 2005) including at least 14 genera cultivated under different growth conditions.”

• cites Abed et al. 2009 sourceNot checked yet

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• cites Das and Veziroglu 2001Not checked yet

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• cites Dutta et al. 2005 sourceNot checked yet

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May combine two claims.

Ethanol production in a high salt concentration medium (1.24 M NaCl) was over 100-fold higher compared with low salt conditions (0.24 M NaCl), resulting in a production of 0.75 mmol/g.

“Ethanol production in a high salt concentration medium (1.24 M NaCl) was over 100-fold higher compared with the low salt conditions (0.24 M NaCl), resulting in a production of 0.75 mmol/g (Carrieri et al. 2010).”

• cites Carrieri et al. 2010 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ethanol produced from renewable resources can be mixed with existing diesel and used without any modification of existing diesel engines.

“Ethanol produced from renewable resources is an appealing energy source due to the fact that it can be mixed with existing diesel and used without any modification of existing diesel engines (Kaygusuz 2009).”

• cites Kaygusuz 2009 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

The photanol modified organism uses solar energy to convert CO2 into biofuel with minimized steps, leading to an increase in biofuel production efficiency compared to current biofuel production processes, reaching theoretical levels of 105 L ha−1 year−1.

“This modified organism uses solar energy to convert CO2 into biofuel with the advantage that the number of steps to do so has been minimised. This has lead to an increase in biofuel production efficiency compared to the current biofuel production processes reaching theoretical levels of 105 L ha−1 year−1.”

• cites Hellingwerf and de Mattos 2009 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Bioethanol is currently produced by fermentation of agricultural crops, mainly sugarcane in Brazil and/or corn in the US.

“Currently, bioethanol is produced by fermentation of agricultural crops, mainly sugarcane in Brazil (Goldemberg 2007) and/or corn in the US (Hill et al. 2006).”

• cites Goldemberg 2007 sourceNot checked yet

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• cites Hill et al. 2006 sourceNot checked yet

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Probably not a substantial claim: may not pass S2 (checkable).

The use of cyanobacteria to harness solar energy for the production of different types of bioenergy might represent a simpler and cleaner system for the production of sustainable energy.

“In conclusion, it can be stated that the use of cyanobacteria to harness solar energy for the production of different types of bioenergy might represent a simpler and cleaner system for the production of sustainable energy.”

• AssumptionRests on an assumption: Cyanobacteria can contain considerable amounts of lipids, mainly present in the thylakoid membranes.
• AssumptionRests on an assumption: Cyanobacteria possess higher photosynthetic levels and growth rates compared to other algae and higher plants.
• AssumptionRests on an assumption: Cyanobacteria grow easily with basic nutritional requirements and cultivation is relatively simple and inexpensive.
• AssumptionRests on an assumption: Cyanobacteria, being prokaryotes, can much more readily be genetically engineered to enhance biofuel production than eukaryotic algae.

May combine two claims.

Fermentation took place under dark conditions when no photosynthetic oxygen was produced, thus excluding respiration for energy production.

“Fermentation took place under dark conditions when no photosynthetical oxygen was produced, thus excluding respiration for energy production.”

• cites Heyer and Krumbein 1991 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Of 37 cyanobacterial strains screened, 16 were able to produce ethanol as one of the fermentation products, and significant quantities of ethanol were produced in two Oscillatoria strains (>10 μmol/sample).

“Of the 37 strains studied, it was found that 16 strains were able to produce ethanol as one of the fermentation products while significant quantities of ethanol were produced in two Oscillatoria strains (>10 μmol/sample).”

• cites Heyer and Krumbein 1991 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Griffiths and Harrison (2009) collected data on biodiesel production of 55 microalgae species; Synechococcus with a production of 75 mg/L of lipids per day was among the highest yielding strains.

“Griffiths and Harrison (2009) collected data on the biodiesel production of 55 microalgae species. Synechococcus with a production of 75 mg/L of lipids per day was among the highest yielding strains.”

• cites Griffiths and Harrison 2009Not checked yet

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May combine two claims.

Vargas and co-workers analyzed the biochemical composition of 12 N2-fixing cyanobacteria; lipid content ranged between 8-12% dw, with Nodularia and Nostoc containing the highest amount of lipids.

“Vargas and co-workers (Vargas et al. 1998) analyzed the biochemical composition of 12 N2-fixing cyanobacteria. The content of the lipids in these strains ranged between 8–12% dw, of which Nodularia and Nostoc contained the highest amount of lipids.”

• cites Vargas et al. 1998 sourceNot checked yet

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May combine two claims.

Cyanobacteria have the fastest growth rates and lipid productivity was amongst the highest in exponentially growing cultures.

“It was, however, shown that cyanobacteria have the fastest growth rates and that the lipid productivity was amongst the highest in exponentially growing cultures (Sheehan et al. 1998).”

• cites Sheehan et al. 1998Not checked yet

  Not checked in the free run.

May combine two claims.

In 1998, 3,000 species of microalgae were screened in the Aquatic Species Program to identify species with high lipid content; little information regarding cyanobacteria was provided since they do not accumulate high amounts of lipids.

“In 1998, 3,000 species of microalgae were screened in the Aquatic Species Program with the aim to identify species with high lipid content. In this program, little information regarding cyanobacteria was provided since they do not accumulate high amounts of lipids.”

• cites Sheehan et al. 1998Not checked yet

  Not checked in the free run.

May combine two claims.

The amount of polyunsaturated fatty acids (PUFA) was decreased and those of monounsaturated fatty acids (MUFA) were increased at high light intensities.

“The amount of polyunsaturated fatty acids (PUFA) was also decreased and those of monounsaturated fatty acids (MUFA) were increased at high light intensities (Walsh et al. 1997).”

• cites Walsh et al. 1997 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

A high content in unsaturated fatty acids decreases oil oxidation stability, while biodiesel consisting of saturated long chain fatty acids shows poor cold-flow properties.

“Moreover, a high content in unsaturated fatty acids is responsible for decreasing the oil oxidation stability while biodiesel consisting of saturated long chain fatty acids shows poor cold-flow properties (Knothe 2008; Pinzi et al. 2009).”

• cites Knothe 2008 sourceNot checked yet

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• cites Pinzi et al. 2009 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Around 2,000 species of cyanobacteria have been identified.

“Around 2,000 species of cyanobacteria have been identified (Sheehan et al. 1998)”

• cites Sheehan et al. 1998Not checked yet

  Not checked in the free run.

May combine two claims.

Nagarkar et al. (2004) reported chemical composition and calorific values of 13 cyanobacteria species; calorific values varied between 15-33 kJ 10 g−1 dw, with Spirulina and Phormidium responsible for higher values, and high calorific values correlated with high protein content.

“Nagarkar et al. (2004) reported on the chemical composition and their respective calorific values of 13 cyanobacteria species (they did not report on the lipid content). They found that the calorific values varied between 15–33 kJ 10 g−1 dw with Spirulina and Phormidium responsible for the higher values. They could also correlate the high calorific values with high protein content.”

• cites Nagarkar et al. 2004 sourceNot checked yet

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May combine two claims.

The fatty acid composition is often governed by growth temperature, where the degree of unsaturation increases at lower temperatures and biosynthesis of shorter acyl chains occurs.

“The fatty acid composition is often governed by the growth temperature where the degree of unsaturation increases at lower temperatures and the biosynthesis of shorter acyl chains occur (Liu et al. 2005).”

• cites Liu et al. 2005 sourceNot checked yet

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May combine two claims.

A recent comparison of different strains of microalgae revealed that although cyanobacteria possessed the highest biomass productivity, they showed a low lipid content reflecting the high metabolic cost of lipid synthesis.

“On the other hand, a recent comparison of different strains of microalgae revealed that although cyanobacteria possessed the highest biomass productivity, it showed a low lipid content reflecting the high metabolic cost of lipid synthesis (Francisco et al. 2010).”

• cites Francisco et al. 2010 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

An increase of cyanobacterial biomass and lipid content is observed in strains grown in wastewater from the swine industry.

“An increase of cyanobacterial biomass and lipid content is observed in strains grown in wastewater from the swine industry (Cañizares-Villanueva et al. 1995).”

• cites Cañizares-Villanueva et al. 1995 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Microorganisms can convert light into electric energy with photoelectrochemical cells.

“It has recently been reported that microorganisms can convert light into electric energy with the use of photoelectrochemical cells.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, 2-phosphoglycolate is degraded via the glycerate and decarboxylation pathway.

“Besides photorespiration, in cyanobacteria, this molecule is degraded via the glycerate and decarboxylation pathway.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

The major route of glucose degradation is the OPP cycle and is considered the main CO2 fixation mechanism in cyanobacteria.

“The major route of glc degradation is the OPP cycle and is considered as the main CO2 fixation mechanism in cyanobacteria.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, photosynthesis and respiration co-occur in a single compartment within the cell, the thylakoid membrane.

“Unlike most other phototrophs, in cyanobacteria, photosynthesis and respiration co-occur in a single compartment within the cell, the thylakoid membrane.”

May combine two claims.

Mesophilic temperatures at 35°C seem to be optimum for maximum CH4 yield from Spirulina maxima (around 0.40 L CH4/g VS fed) with an energy conversion efficiency of 59%.

“Mesophilic temperatures at 35°C seem to be optimum for a maximum yield (around 0.40 L CH4/g VS fed) with an energy conversion efficiency of 59%.”

• cites Samson and Leduy 1982, 1986Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Varel et al. 1988 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

The CCM contains two carbon-fixing enzymes, Rubisco and carbonic anhydrases, stored in carboxysomes.

“The CCM contains two carbon-fixing enzymes, Rubisco and carbonic anhydrases, stored in carboxysomes.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Cyanobacteria possess an additional CO2 assimilation mechanism operated by PEPC and malic acid to assist in fixation of large amounts of CO2, similar to the C4 pathway in plants.

“Although Rubisco is the main enzyme responsible for the C fixation, cyanobacteria possess an additional assimilation mechanism operated by phosphoenolpyruvate carboxylase (PEPC) and malic acid to assist them in the fixation of large amounts of CO2 which is similar to the C4 pathway in plants (Yang et al. 2002).”

• cites Yang et al. 2002 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Converting residual cyanobacterial biomass to CH4 after lipid extraction leads to a more favourable or positive energetic balance of overall biofuels production by cyanobacteria and could decrease total costs.

“This will lead to a more favourable or positive energetic balance of the overall biofuels production by cyanobacteria, which could also decrease the total costs of the process for bioenergy production.”

May combine two claims.

Biochemical composition can vary according to the growth phase, with the highest lipids occurring as the culture entered the stationary phase.

“Finally, biochemical composition can also vary according to the growth phase, with the highest lipids occurring as the culture entered in the stationary phase (Vargas et al. 1998).”

• cites Vargas et al. 1998 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

When algae accumulate less than 40% of lipids, oil recovery results in 21% of the energetic value but the energetic costs of lipid recovery are higher than 30%.

“Furthermore, when the algae accumulate less than 40% of lipids, the oil recovery results in a 21% of the energetic value but the energetic costs of lipid recovery involved are higher than 30% (Sialve et al. 2009).”

• cites Sialve et al. 2009 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

2-phosphoglycolate is a noxious by-product of Rubisco oxygenase activity which inhibits important enzymes in the Calvin cycle (phosphofructokinase and triosephosphate isomerase).

“The 2-phosphoglycolate (P-glycolate) is a noxious by-product of the Rubisco oxygenase activity which inhibits important enzymes in the Calvin cycle (phosphofructokinase and triosephosphate isomerase).”

Probably not a substantial claim: may not pass S4 (based).

Cyanobacterial Rubisco possesses a relatively low affinity for CO2 compared to other algae or higher plants.

“It is well known that cyanobacterial Rubisco possesses a relative low affinity for CO2 when compared to other algae or higher plants.”

Classified as probably not a substantial claim.

Cyanobacteria have developed a CO2-concentrating mechanism (CCM) to overcome the low affinity of Rubisco for CO2.

“In order to overcome this problem, they have developed a CO2-concentrating mechanism (CCM).”

May combine two claims.

Unicellular cyanobacteria generally lack PUFA, while most filamentous species contain high levels of di- and trienoic fatty acids.

“Generally, unicellular types of cyanobacteria lack PUFA, while most of the filamentous species contain high levels of di- and trienoic fatty acids (Kenyon 1972; Kenyon et al. 1972).”

• cites Kenyon 1972Not checked yet

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• cites Kenyon et al. 1972Not checked yet

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May combine two claims.

In cyanobacteria, carboxysomes possess a specific organization through the cell, not found in other prokaryotes, and this distribution is closely linked to CO2 fixation efficiency.

“A recent study has shown that in cyanobacteria, carboxysomes possess a specific organization through the cell, not found in other prokaryotes, and this distribution is closely linked to the CO2 fixation efficiency.”

• cites Savage et al. 2010 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Not much research has been performed on CH4 production by cyanobacteria biomass, leading to insufficient information in literature to compare yields of different cyanobacteria strains.

“Therefore, not much research has been performed on the CH4 production by cyanobacteria biomass leading to insufficient information in literature in order to compare the yield of different cyanobacteria strains.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Cyanobacteria grown in the dark have lower growth rates than when grown under light conditions.

“Nevertheless, cyanobacteria grown in the dark have shown lower growth rates than when grown under light conditions (Stanier and Cohenbazire 1977).”

• cites Stanier and Cohenbazire 1977 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Under light conditions, PSI competes with terminal oxidase for electrons to maximize the amount of NADPH required for CO2 fixation.

“Under light conditions, PSI competes with terminal oxidase for electrons to maximize the amount of NADPH required for CO2 fixation (Vermaas 2001).”

• cites Vermaas 2001Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

In photoelectrochemical cells, high-energy electrons produced by light excitation in photosystems are transferred to an electron mediator, which transfers them to an electrode, producing electricity.

“In these cells, high-energy electrons produced by the light excitation in the photosystems are transferred to an electron mediator, which in turn transfers them to an electrode and thereby producing electricity.”

May combine two claims.

Anabaena sp. was shown to biodegrade cyanides and produce CH4 in batch reactors.

“The N2-fixing cyanobacterium, Anabaena sp., was shown to be able to biodegrade cyanides and thereby producing CH4 in batch reactors.”

• cites Gantzer and Maier 1990Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Spirulina possesses a known high nutritional value that could reduce the production costs of energy production by this mean.

“This species possess a known high nutritional value that could reduce the production costs of the energy production by this mean (Behera et al. 2007).”

• cites Behera et al. 2007 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Two cytoskeletal proteins, par A and merB, are involved in the organization of the specific carboxysomal pattern.

“It seems that two cytoskeletal proteins, par A (involved in chromosome and plasmid segregation) and merB (involved in cell morphology), are involved in the organization of this specific carboxysomal pattern (Savage et al. 2010).”

• cites Savage et al. 2010 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Sucrose synthase seems to be present only in filamentous N2-fixing cyanobacteria, where it is involved in the accumulation of storage and structural polysaccharides.

“This enzyme seems to be present only in filamentous N2-fixing cyanobacteria (Curatti et al. 2000; Salerno and Curatti 2003) where it is involved in the accumulation of storage (glycogen and sucrose) and structural (such as cellulose, see below) polysaccharides (Curatti et al. 2008).”

• cites Curatti et al. 2000 sourceNot checked yet

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• cites Salerno and Curatti 2003 sourceNot checked yet

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• cites Curatti et al. 2008 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Gene disruption experiments indicated that trehalose, like sucrose, plays a crucial role in dehydration and salt stress tolerance in different organisms.

“Gene disruption experiments indicated that trehalose, like sucrose, plays a crucial role in dehydration (Asthana et al. 2008; Higo et al. 2006) and salt stress tolerance (Salerno et al. 2004) in different organisms.”

• cites Asthana et al. 2008 sourceNot checked yet

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• cites Higo et al. 2006 sourceNot checked yet

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• cites Salerno et al. 2004 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Overexpression of GPAT or AGPAT led to higher lipid levels in Arabidopsis thaliana seeds.

“The overexpression of GPAT or AGPAT led to higher lipid levels in Arabidopsis thaliana seeds (Ranalli 2007).”

• cites Ranalli 2007 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Sucrose accumulation in cyanobacteria during conditions of salt stress or desiccation plays a fundamental role as an osmotic protective agent.

“Sucrose (α-D-glucopyranosyl β-D-fructofuranoside) accumulation in cyanobacteria during conditions of salt stress or desiccation plays a fundamental role as an osmotic protective agent (Billi et al. 2000; Miao et al. 2003a).”

• cites Billi et al. 2000 sourceNot checked yet

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• cites Miao et al. 2003aNot checked yet

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Classified as probably not a substantial claim.

The first committed reaction in fatty acid biosynthesis is an enzymatic reaction catalysed by ACCase.

“As pointed out before, the first committed reaction in the fatty acid biosynthesis is an enzymatic reaction catalysed by ACCase.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In wild type cyanobacteria, fermentation does not seem to supply a significant amount of energy to the cell.

“However, as mentioned before (“Ethanol” section) in wild type cyanobacteria, fermentation does not seem to supply a significant amount of energy to the cell.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Acyl-ACPs are also able to inhibit 3-ketoacyl-ACP synthase and enoyl-ACP reductase activities.

“In addition, Heath and coworkers (Heath and Rock 1995, 1996a, b) found that acyl-ACPs are also able to inhibit the 3-ketoacyl-ACP synthase and enoyl-ACP reductase activities.”

• cites Heath and Rock 1995, 1996a, bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

ADP-glucose diphosphorylase (AGPase) controls glycogen synthesis in bacteria in an ATP-dependent reaction and seems to be regulated by 3PG (activator) and Pi (inhibitor).

“The enzyme ADP-glucose diphosphorylase (AGPase; EC 2.7.7.27, encoded by the agp gene, also known as glgC) controls glycogen synthesis in bacteria in an ATP-dependent reaction and seems to be regulated by 3PG (activator) and Pi (inhibitor) (Ballicora et al. 2003; Gomez-Casati et al. 2003).”

• cites Ballicora et al. 2003 sourceNot checked yet

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• cites Gomez-Casati et al. 2003 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Glycogen is the main carbon and energy storage polysaccharide in cyanobacteria.

“Glycogen is the main carbon and energy storage polysaccharide in cyanobacteria.”

May combine two claims.

GPAT is negatively regulated by ppGpp, leading to a decrease in lipid synthesis and consequently a decrease in fatty acid production through accumulation of fatty acyl-ACPs, responsible for inhibition of several steps in fatty acid synthesis.

“Previous results indicated that GPAT is negatively regulated by ppGpp leading to a decrease in the lipid synthesis and consequently a decrease in the fatty acid production through the accumulation of fatty acyl-ACPs, responsible of the inhibition of several steps (previously mentioned) in fatty acid synthesis.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

ACCase activity is inhibited by acyl-ACP, and this end product plays a fundamental role in fatty acid synthesis control.

“As mentioned earlier, ACCase activity is inhibited by this acyl-ACP and thereby this end product plays a fundamental role in the fatty acid synthesis control.”

May combine two claims.

Synechococcus sp. PCC 7942 was genetically modified to secrete non-crystalline cellulose into the growth media, which is a promising candidate for ethanol production.

“Recently, Synechococcus sp. PCC 7942 was genetically modified to secrete non-crystalline cellulose into the growth media, which is a promising candidate for ethanol production (Nobles and Brown 2008), as discussed in “Ethanol” section.”

• cites Nobles and Brown 2008 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

Many of the cited strategies for cyanobacterial biofuel production are still under development and their energy yield may not yet be economically feasible at industrial production levels.

“Many of the cited strategies are still under development and their energy yield may not be economically feasible yet at industrial production levels.”

Probably not a substantial claim: may not pass S3 (load-bearing).

2-oxoglutarate modulates N and C metabolism in non-nitrogen-assimilating cyanobacteria.

“In the same way, this compound is also considered to modulate the N and C metabolism in non-nitrogen-assimilating cyanobacteria (Eisenhut et al. 2008; Muro-Pastor et al. 2005).”

• cites Eisenhut et al. 2008 sourceNot checked yet

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• cites Muro-Pastor et al. 2005 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Previous studies in eukaryotic algae have shown that the inactivation of genes involved in the biosynthesis of starch causes an enhanced lipid production.

“Previous studies in eukaryotic algae have shown that the inactivation of genes involved in the biosynthesis of starch, another storage compound, causes an enhanced lipid production (Ramazanov and Ramazanov 2006).”

• cites Ramazanov and Ramazanov 2006Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, reducing power is mainly generated during photosynthesis.

“Thus, in cyanobacteria, the reducing power is mainly generated during photosynthesis (Muro-Pastor and Florencio 1992).”

• cites Muro-Pastor and Florencio 1992 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, 2-oxoglutarate is directly involved in N2 fixation via the NH3-assimilating mechanisms GDH and GS-GOGAT.

“In these microorganisms, 2-OG is directly involved in the N2 fixation via the NH3-assimilating mechanisms, GDH (gdhA, EC 1.4.1.14) (Chávez and Candau 1991) and GS-GOGAT route (Meeks et al. 1978).”

• cites Chávez and Candau 1991 sourceNot checked yet

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• cites Meeks et al. 1978 sourceNot checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

An increase in fatty acid production has been achieved in E. coli by deleting fadD in combination with the overexpression of other key genes of the fatty acid pathway.

“As pointed out before, an increase in fatty acid production has been achieved already in E. coli by deleting fadD in combination with the overexpression of other key genes of the fatty acid pathway (Lu et al. 2008).”

• cites Lu et al. 2008Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, 2-oxoglutarate is implicated in heterocyst differentiation.

“Furthermore, in cyanobacteria, 2-OG seems to be implicated in the heterocyst differentiation. Previous studies have indicated that the activity of key enzymes in the heterocyst development, including NtcA and PII, is subjected to 2-OG concentrations (Zhang et al. 2005).”

• cites Zhang et al. 2005Not checked yet

  Not checked in the free run.

The quote only partly states this claim.

The greater effectiveness of PEPC in carbon assimilation compared with Rubisco could explain why carbon flux in cyanobacteria is primarily allocated to protein biosynthesis.

“This fact could explain why C flux, in cyanobacteria, is primarily allocated to the protein biosynthesis.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The production of 2-oxoglutarate by the GS-GOGAT mechanism is insignificant compared with IDH activity.

“However, the production of 2-OG by this mechanism is rather insignificant if compared with IDH activity (Muro-Pastor and Florencio 1992).”

• cites Muro-Pastor and Florencio 1992 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

The success of future generation biofuels will rely on advances in metabolic engineering to optimize existing energy-related biosynthetic pathways and to reduce stress on genetically modified organisms.

“In conclusion, the success of future generation of biofuels will rely on the advances in metabolic engineering to optimize the existing energy-related biosynthetic pathways and to reduce the stress on the genetically modified organisms.”

May combine two claims.

Another study on agp-deficient mutants suggested that low light intensities (45 μmol photon m−2 s−1) increase moderately the cell growth, whereas higher intensities (82 μmol photon m−2 s−1) reduce the growth.

“Another study on agp-deficient mutants suggested that low light intensities (45 μmol photon m−2 s−1) increase moderately the cell growth, whereas higher intensities (82 μmol photon m−2 s−1) reduce the growth (Miao et al. 2003b).”

• cites Miao et al. 2003bNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S4 (based).

Cyanobacteria seem able to cope with some of the major difficulties encountered with preceding biofuel generations.

“In this context, cyanobacteria have received significant consideration stimulated by the fact that these microorganisms seem able to cope with some of the major difficulties encountered with preceding biofuel generations.”

Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

An efficient and cost-effective fuel production from biomass should decrease our current dependence on conventional energies which are both scarce and polluting.

“An efficient and cost-effective fuel production from biomass should decrease our current dependence on conventional energies which are both scarce and polluting.”

May combine two claims.

These results indicate that agp mutants are able to harness the chemical energy from photosynthesis more efficiently at low light conditions; at higher intensities impaired glycogen synthesis would cause photosynthesis inhibition (feedback inhibition).

“These results indicate that agp mutants are able to harness the chemical energy from photosynthesis more efficiently at low light conditions; at higher intensities impaired glycogen synthesis would cause photosynthesis inhibition (feedback inhibition).”

Probably not a substantial claim: may not pass S3 (load-bearing).

TCA intermediates usually suppress pyruvate kinase activity, the main modulating enzyme in carbohydrate catabolism.

“Usually, TCA intermediates cause the suppression of pyruvate kinase activity, the main modulating enzyme in carbohydrate catabolism (Lin et al. 1989).”

• cites Lin et al. 1989 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

2-oxoglutarate plays a fundamental role in amino acid biosynthesis.

“It has been suggested that 2-OG plays a fundamental role in the amino acid biosynthesis. This theory has been supported in Synechocystis by experiments where the external addition of ammonium to N2-free medium enhanced the 2-OG levels as well as the glutamate and glutamine production (Merida et al. 1991).”

• cites Merida et al. 1991 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

In cyanobacteria, succinate can originate from 2-oxoglutarate using a different route.

“It seems that in cyanobacteria, succinate can originate from 2-OG using a different route (Cooley et al. 2000).”

• cites Cooley et al. 2000 sourceNot checked yet

  Not checked in the free run.

May combine two claims.

PEPC lacks oxygenase activity and is therefore more effective in carbon assimilation than Rubisco, whose carboxylase and oxygenase activities compete.

“It should be pointed out that PEPC lacks oxygenase activity and is therefore more effective in the C assimilation than Rubisco where carboxylase and oxygenase activities compete with each other (Gillion 1998).”

• cites Gillion 1998Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Previous modelling in Synechocystis PCC6803 suggested that the lack of a completed TCA cycle does not diminish growth significantly.

“Their results suggested that the lack of a completed TCA cycle does not diminish the growth significantly in this microorganism.”

• cites Shastri and Morgan 2005 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S4 (based).

Metabolic engineering of metabolic pathways could cause unplanned and unforeseen deleterious effects on cellular function.

“As indicated previously, metabolic engineering of metabolic pathways could cause unplanned and unforeseen deleterious effects on cellular function.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Proving the role of 2-oxoglutarate as a signalling compound is challenging because it is quickly diverted into different metabolic processes.

“However, proving the role of 2-OG as a signalling compound is still challenging since it is quickly diverted into different metabolic processes.”