Metabolic flux analysis of Cyanothece sp. ATCC 51142 under mixotrophic conditions

Alagesan, Swathi; Gaudana, Sandeep B.; Sinha, Avinash; Wangikar, Pramod P.
November 2013
Photosynthesis Research;Nov2013, Vol. 117 Issue 1-3, p191
Academic Journal
Cyanobacteria are a group of photosynthetic prokaryotes capable of utilizing solar energy to fix atmospheric carbon dioxide to biomass. Despite several “proof of principle” studies, low product yield is an impediment in commercialization of cyanobacteria-derived biofuels. Estimation of intracellular reaction rates by 13C metabolic flux analysis ( 13C-MFA) would be a step toward enhancing biofuel yield via metabolic engineering. We report 13C-MFA for Cyanothece sp. ATCC 51142, a unicellular nitrogen-fixing cyanobacterium, known for enhanced hydrogen yield under mixotrophic conditions. Rates of reactions in the central carbon metabolism under nitrogen-fixing and -non-fixing conditions were estimated by monitoring the competitive incorporation of 12C and 13C from unlabeled CO 2 and uniformly labeled glycerol, respectively, into terminal metabolites such as amino acids. The observed labeling patterns suggest mixotrophic growth under both the conditions, with a larger fraction of unlabeled carbon in nitrate-sufficient cultures asserting a greater contribution of carbon fixation by photosynthesis and an anaplerotic pathway. Indeed, flux analysis complements the higher growth observed under nitrate-sufficient conditions. On the other hand, the flux through the oxidative pentose phosphate pathway and tricarboxylic acid cycle was greater in nitrate-deficient conditions, possibly to supply the precursors and reducing equivalents needed for nitrogen fixation. In addition, an enhanced flux through fructose-6-phosphate phosphoketolase possibly suggests the organism’s preferred mode under nitrogen-fixing conditions. The 13C-MFA results complement the reported predictions by flux balance analysis and provide quantitative insight into the organism’s distinct metabolic features under nitrogen-fixing and -non-fixing conditions.


Related Articles

  • Reconstruction and Comparison of the Metabolic Potential of Cyanobacteria Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803. Saha, Rajib; Verseput, Alex T.; Berla, Bertram M.; Mueller, Thomas J.; Pakrasi, Himadri B.; Maranas, Costas D. // PLoS ONE;Oct2012, Vol. 7 Issue 10, Special section p1 

    Cyanobacteria are an important group of photoautotrophic organisms that can synthesize valuable bio-products by harnessing solar energy. They are endowed with high photosynthetic efficiencies and diverse metabolic capabilities that confer the ability to convert solar energy into a variety of...

  • Kinetic modeling and exploratory numerical simulation of chloroplastic starch degradation. Nag, Ambarish; Lunacek, Monte; Graf, Peter A.; Chang, Christopher H. // BMC Systems Biology;2011, Vol. 5 Issue 1, p94 

    Background: Higher plants and algae are able to fix atmospheric carbon dioxide through photosynthesis and store this fixed carbon in large quantities as starch, which can be hydrolyzed into sugars serving as feedstock for fermentation to biofuels and precursors. Rational engineering of carbon...

  • Integrative analysis of large scale expression profiles reveals core transcriptional response and coordination between multiple cellular processes in a cyanobacterium. Singh, Abhay K.; Elvitigala, Thanura; Cameron, Jeffrey C.; Ghosh, Bijoy K.; Bhattacharyya-Pakrasi, Maitrayee; Pakrasi, Himadri B. // BMC Systems Biology;2010, Vol. 4, p105 

    Background: Cyanobacteria are the only known prokaryotes capable of oxygenic photosynthesis. They play significant roles in global biogeochemical cycles and carbon sequestration, and have recently been recognized as potential vehicles for production of renewable biofuels. Synechocystis sp. PCC...

  • Flux Balance Analysis of Cyanobacterial Metabolism: The Metabolic Network of Synechocystis sp. PCC 6803. Knoop, Henning; Gründel, Marianne; Zilliges, Yvonne; Lehmann, Robert; Hoffmann, Sabrina; Lockau, Wolfgang; Steuer, Ralf // PLoS Computational Biology;Jun2013, Vol. 9 Issue 6, p1 

    Cyanobacteria are versatile unicellular phototrophic microorganisms that are highly abundant in many environments. Owing to their capability to utilize solar energy and atmospheric carbon dioxide for growth, cyanobacteria are increasingly recognized as a prolific resource for the synthesis of...

  • Percent Photosynthesis (Net CO2 Exchange Rate) Increases for 300, 600 and 900 ppm Increases in the Air's CO2 Concentration:.  // CO2 Science;12/11/2014, p1 

    Two charts are presented which explain the percentage of increased photosynthesis for 300, 600 and 900 part per million in the air's carbon dioxide concentration.

  • Carbon Availability Affects Diurnally Controlled Processes and Cell Morphology of Cyanothece 51142. Stöckel, Jana; Elvitigala, Thanura R.; Liberton, Michelle; Pakrasi, Himadri B. // PLoS ONE;Feb2013, Vol. 8 Issue 2, p1 

    Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria to convert solar energy and high concentrations of CO2 efficiently into biomass and renewable energy sources has sparked substantial...

  • A faster Rubisco with potential to increase photosynthesis in crops. Lin, Myat T.; Occhialini, Alessandro; Andralojc, P. John; Parry, Martin A. J.; Hanson, Maureen R. // Nature;9/25/2014, Vol. 513 Issue 7519, p547 

    In photosynthetic organisms, d-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is the major enzyme assimilating atmospheric CO2 into the biosphere. Owing to the wasteful oxygenase activity and slow turnover of Rubisco, the enzyme is among the most important targets for improving the...

  • Acyl homoserine lactone-based quorum sensing in a methanogenic archaeon. Zhang, Guishan; Zhang, Fan; Ding, Gang; Li, Jie; Guo, Xiaopeng; Zhu, Jinxing; Zhou, Liguang; Cai, Shichun; Liu, Xiaoli; Luo, Yuanming; Zhang, Guifeng; Shi, Wenyuan; Dong, Xiuzhu // ISME Journal: Multidisciplinary Journal of Microbial Ecology;Jul2012, Vol. 6 Issue 7, p1336 

    Acyl homoserine lactone (AHL)-based quorum sensing commonly refers to cell density-dependent regulatory mechanisms found in bacteria. However, beyond bacteria, this cell-to-cell communication mechanism is poorly understood. Here we show that a methanogenic archaeon, Methanosaeta harundinacea...

  • Productivity of well-watered Panicum virgatum does not increase with CO2 enrichment. Fay, Philip A.; Polley, H. Wayne; Jin, Virginia L.; Aspinwall, Michael J. // Journal of Plant Ecology;Oct2012, Vol. 5 Issue 4, p366 

    Aims Rising atmospheric CO2 has been shown to increase aboveground net primary productivity (ANPP) in water-limited perennial grasslands, in part by reducing stomatal conductance and transpiration, thereby reducing depletion of soil moisture. However, the benefits of CO2 enrichment for ANPP will...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics