Project description:Coupling of cellular processes and their coordinated oscillations under continuous light in cyanothece sp. ATCC 51142, a diazotrophic unicellular cyanobacteria
Project description:Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria in converting solar energy and high concentrations of CO2 (e.g. flue gas from coal power plants) efficiently into biomass and renewable energy sources is of interest to many research fields. In order to guide further advances in this area, a better understanding about the metabolic changes that occur under conditions of high CO2 is important. The objective of this study is to utilize genome-wide microarray expression profiling in the unicellular diazotrophic cyanobacterium Cyanothece 51142 grown in 8% CO2-enriched air and to determined the impact of high CO2 on cyanobacterial cell physiology and growth. Study of metabolic and cellular adaptations to high CO2 conditions in the unicellular diazotrophic cyanobacterium Cyanothece 51142. Two-condition experiment: 0.03% CO2 vs. 8% CO2. Biological replicates: 2; technical replicates: 3; Spots/ORF: 3 per Chip. Samples were collected at 7 time points over a period of two days, namely, Day1_30minLight (30min), Day1_2hrsLight (2hr), Day1_6hrsLight (6hr), Day1_1hrsDark (13hr), Day1-6hrsDark (18hr), Day2_6hrsLight (30hr) and Day2_6hrsDark (42hr).
Project description:Cyanobacteria are oxygenic photoautotrophs notable for their ability to utilize atmospheric CO2 as the major source of carbon. The prospect of using cyanobacteria in converting solar energy and high concentrations of CO2 (e.g. flue gas from coal power plants) efficiently into biomass and renewable energy sources is of interest to many research fields. In order to guide further advances in this area, a better understanding about the metabolic changes that occur under conditions of high CO2 is important. The objective of this study is to utilize genome-wide microarray expression profiling in the unicellular diazotrophic cyanobacterium Cyanothece 51142 grown in 8% CO2-enriched air and to determined the impact of high CO2 on cyanobacterial cell physiology and growth.
Project description:Transcriptional profiling of a unicelluar diazotrophic cyanobacterium Cyanothece sp. ATCC 51142 in constant light under nitrogen fixing condition. The controls comprised of equimolar pool of RNA from all time points. Cyanothece sp. ATCC 51142 was grown in BG-11 medium without nitrate. The culture was entrained under 12 h alternate light/dark cycles for 96 h and released in constant light (LL). Nine samples were for two consecutive cycles under LL, at times when the culture underwent transitions in its photosynthetic and respiratory phases, as indicated by the exit CO2 and O2 profiles. Two biological replicates, two technical replicates and a dye swap were analyzed for each sample from individual time points.
Project description:Transcriptional profiling of a unicelluar diazotrophic cyanobacterium Cyanothece sp. ATCC 51142 in constant light under nitrogen fixing condition. The controls comprised of equimolar pool of RNA from all time points.
Project description:The unicellular cyanobacterium Cyanothece ATCC 51142 is capable of oxygenic photosynthesis and biological N2-fixation (BNF), a process highly sensitive to oxygen. Previous work has focused on determining protein expression levels under different growth conditions. A major gap of our knowledge is an understanding how these expressed proteins are assembled into complexes and organized into metabolic pathways, an area that has not been thoroughly investigated. Here, we combined size-exclusion chromatography (SEC) with label-free quantitative mass spectrometry (MS) and bioinformatics to characterize many protein complexes in the soluble fraction from Cyanothece 51142 cells grown under 12-h light-dark cycle. We identified 1386 proteins in duplicate biological replicates, and 64% of those proteins were identified as putative complexes. Pair-wise computational prediction of protein-protein interaction (PPI) identified 74,822 putative interactions, of which 2337 interactions were highly correlated with published protein co-expressions. Many sequential glycolytic and TCA cycle enzymes were identified as putative complexes. We also identified many membrane complexes that contain cytoplasmic domains. Subunits of NDH-1 complex eluted in a fraction with an approximate mass of ~669 kDa, and subunits composition revealed co-existence of distinct forms of NDH-1 complex subunits responsible for respiration, electron flow and CO2 uptake. The complex form of the phycocyanin beta subunit was non-phosphorylated and the monomer form was phosphorylated at Ser20, suggesting phosphorylation-dependent de-oligomerization of the phycocyanin beta subunit. This study provides an analytical platform for future studies to reveal how these complexes assemble and disassemble as a function of diurnal and circadian rhythms.