title: Metabolic model of Synechococcus sp. PCC 7002: Prediction of flux distribution and network modification for enhanced biofuel production.
abstract: Flux Balance Analysis was performed with the Genome Scale Metabolic Model of a fast growing cyanobacterium Synechococcus sp. PCC 7002 to gain insights that would help in engineering the organism as a production host. Gene essentiality and synthetic lethality analysis revealed a reduced metabolic robustness under genetic perturbation compared to the heterotrophic bacteria Escherichia coli. Under glycerol heterotrophy the reducing equivalents were generated from tricarboxylic acid cycle rather than the oxidative pentose phosphate pathway. During mixotrophic growth in glycerol the photosynthetic electron transport chain was predominantly used for ATP synthesis with a photosystem I/photosystem II flux ratio higher than that observed under autotrophy. An exhaustive analysis of all possible double reaction knock outs was performed to reroute fixed carbon towards ethanol and butanol production. It was predicted that only ∼10% of fixed carbon could be diverted for ethanol and butanol production.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
authors.forename: John I
authors.initials: JI
authors.lastname: Hendry
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
authors.forename: Charulata B
authors.initials: CB
authors.lastname: Prasannan
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
authors.forename: Aditi
authors.initials: A
authors.lastname: Joshi
authors.affiliation: Reliance Technology Group, Reliance Industries Limited, Reliance Corporate Park, Ghansoli, Navi Mumbai 400701, India.
authors.forename: Santanu
authors.initials: S
authors.lastname: Dasgupta
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India; DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Mumbai 400076, India; Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India. Electronic address: wangikar@iitb.ac.in.
authors.forename: Pramod P
authors.initials: PP
authors.lastname: Wangikar
mesh_terms: D052818:Autotrophic Processes; D056804:Biofuels; D000440:Butanols / Q000378:metabolism; D057486:Carbon Cycle; D002952:Citric Acid Cycle; D000431:Ethanol / Q000378:metabolism; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D005990:Glycerol / Q000378:metabolism; D052836:Heterotrophic Processes; D008954:Models, Biological; D009154:Mutation; D010427:Pentose Phosphate Pathway; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D015203:Reproducibility of Results; D046940:Synechococcus / Q000235:genetics* / Q000378:metabolism*
chemical_list: D056804:Biofuels; D000440:Butanols; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D000431:Ethanol; D005990:Glycerol
keywords: Cyanobacteria; Flux Balance Analysis; Genome scale metabolic model; Minimization of Metabolic Adjustments (MOMA); Synechococcus sp. PCC 7002