Dataset Information

Analysis of Thermosynechococcus elongatus BP1 and Meiothermus ruber strain A co-cultured under variable light and oxygen conditions

ABSTRACT: The transcriptional response of the cyanobacteria T. elongatus to co-cultiavation with a heterotrophic partner M. ruber was examined under three varying light levels and three varying oxygen levels.

OTHER RELATED OMICS DATASETS IN: PRJNA362605PRJNA368993

ORGANISM(S): Thermosynechococcus vestitus BP-1 Meiothermus ruber

PROVIDER: GSE93859 | GEO | 2017/01/20

SECONDARY ACCESSION(S): PRJNA362605

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:BACKGROUND: Converting carbon dioxide (CO2) into value-added chemicals using engineered cyanobacteria is a promising strategy to tackle the global warming and energy shortage issues. However, most cyanobacteria are autotrophic and use CO2 as a sole carbon source, which makes it hard to compete with heterotrophic hosts in either growth or productivity. One strategy to overcome this bottleneck is to introduce sugar utilization pathways to enable photomixotrophic growth with CO2 and sugar (e.g., glucose and xylose). Advances in engineering mixotrophic cyanobacteria have been obtained, while a systematic interrogation of these engineered strains is missing. This work aimed to fill the gap at omics level.RESULTS: We first constructed two engineered Synechococcus elongatus YQ2-gal and YQ3-xyl capable of utilizing glucose and xylose, respectively. To investigate the metabolic mechanism, transcriptomic and metabolomic analysis were then performed in the engineered photomixotrophic strains YQ2-gal and YQ3-xyl. Transcriptome and metabolome of wild-type S. elongatus were set as baselines. Increased abundance of metabolites in glycolysis or pentose phosphate pathway indicated that efficient sugar utilization significantly enhanced carbon flux in S. elongatus as expected. However, carbon flux was redirected in strain YQ2-gal as more flowed into fatty acids biosynthesis but less into amino acids. In strain YQ3-xyl, more carbon flux was directed into synthesis of sucrose, glucosamine and acetaldehyde, while less into fatty acids and amino acids. Moreover, photosynthesis and bicarbonate transport could be affected by upregulated genes, while nitrogen transport and assimilation were regulated by less transcript abundance of related genes in strain YQ3-xyl with utilization of xylose.CONCLUSIONS: Our work identified metabolic mechanism in engineered S. elongatus during photomixotrophic growth, where regulations of fatty acids metabolism, photosynthesis, bicarbonate transport, nitrogen assimilation and transport are dependent on different sugar utilization. Since photomixotrophic cyanobacteria is regarded as a promising cell factory for bioproduction, this comprehensive understanding of metabolic mechanism of engineered S. elongatus during photomixotrophic growth would shed light on the engineering of more efficient and controllable bioproduction systems based on this potential chassis.

Project description:Biological CO2 mitigation by photosynthetic microorganisms has emerged as a promising approach for generating biomass-based energy during the course of CO2 fixation. Additionally, cyanobacteria-based biofuels have also garnered immense attention lately because of the depleting fossil fuel reserves and the growing energy demands. Synechococcus elongatus PCC 11801, a fast-growing, high CO2 tolerant, novel isolate of cyanobacteria, is an interesting candidate for metabolic engineering applications. Since under laboratory conditions, it exhibited a high level of tolerance to different environmental stresses (CO2, light, temperature, salts and butanol), it seemed like an encouraging prospect for the production of fuels and other industrially relevant chemicals. This is the first-ever functional global proteomics investigation of Synechococcus elongatus PCC 11801 isolate grown at elevated CO2 levels using high-throughput iTRAQ approach. Three independent biological replicates were analyzed and a total of 861 proteins were identified, out of which 492 proteins were found to be present in all the three replicates. Of these, 248 proteins showing the same trend across the three replicates (≥1.5 fold up-regulation or ≤0.66 fold down-regulation) were chosen for pathway analysis. The metabolic responses were marked with a down-regulation of inorganic carbon transporters alongside an induction of nitrogen transport and absorption proteins in order to uphold the apposite carbon-nitrogen equilibrium. Further acclimation progression exposed an increased expression of proteins taking part in photosynthesis and generation of light harvesting pigments such as chlorophyll. Similarly, a downshift of proteins involved in photoprotection and defense against ROS (reactive oxygen species) was observed. Another principal discovery was the perturbation in expression of proteins belonging to central metabolic pathways like glycolysis, TCA cycle, pentose phosphate pathway as a coping mechanism to high CO2 stress. Further, validation studies were carried out using MRM assays and western blotting of key altered proteins.

Dataset Information

Analysis of Thermosynechococcus elongatus BP1 and Meiothermus ruber strain A co-cultured under variable light and oxygen conditions

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure