Project description:Application of genome-scale 'omics approaches to dissect subcellular pathways and regulatory networks governing the fast-growing response of Synechococcus sp. PCC 7002 response to variable irradience levels. We employed controlled cultivation and next-generation sequencing technology to identify transcriptional responses of euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 grown under steady state conditions at six irradiance levels ranging from 33 to 760 µmol photons m-2 sec-1.
Project description:Application of genome-scale 'omics approaches to dissect subcellular pathways and regulatory networks governing the fast-growing response of Synechococcus sp. PCC 7002 response to variable irradience levels.
Project description:Cyanobacteria are valuable organisms for studying the physiology of photosynthesis and carbon fixation as well as metabolic engineering for the production of fuels and chemicals. This work describes a novel counter selection method for the cyanobacterium Synechococcus sp. PCC 7002 based on organic acid toxicity. The organic acids acrylate, 3-hydroxypropionate, and propionate were shown to be inhibitory towards PCC 7002 and other cyanobacteria at low concentrations. Inhibition was overcome by a loss of function mutation in the gene acsA. Loss of AcsA function was used as a basis for an acrylate counter selection method. DNA fragments of interest were inserted into the acsA locus and strains harboring the insertion were isolated on selective medium containing acrylate. This methodology was also used to introduce DNA fragments into a pseudogene, glpK. Application of this method will allow for more advanced genetics and engineering studies in PCC 7002 including the construction of markerless gene deletions and insertions. The acrylate counter-selection could be applied to other cyanobacterial species where AcsA activity confers acrylate sensitivity (e.g. Synechocystis sp. PCC 6803).
Project description:Proteogenomics analysis was employed to refine the genome annotation and provide new insights into nitrogen metabolism of Nostoc sp. PCC 7120.
Project description:Cyanobacteria are valuable organisms for studying the physiology of photosynthesis and carbon fixation as well as metabolic engineering for the production of fuels and chemicals. This work describes a novel counter selection method for the cyanobacterium Synechococcus sp. PCC 7002 based on organic acid toxicity. The organic acids acrylate, 3-hydroxypropionate, and propionate were shown to be inhibitory towards PCC 7002 and other cyanobacteria at low concentrations. Inhibition was overcome by a loss of function mutation in the gene acsA. Loss of AcsA function was used as a basis for an acrylate counter selection method. DNA fragments of interest were inserted into the acsA locus and strains harboring the insertion were isolated on selective medium containing acrylate. This methodology was also used to introduce DNA fragments into a pseudogene, glpK. Application of this method will allow for more advanced genetics and engineering studies in PCC 7002 including the construction of markerless gene deletions and insertions. The acrylate counter-selection could be applied to other cyanobacterial species where AcsA activity confers acrylate sensitivity (e.g. Synechocystis sp. PCC 6803). Cultures were grown in medium modified with 5mM acrylic acid at pH 8 and compared to cultures grown in unmodified medium. Samples were processed in duplicate.
Project description:Halotolerant species are of interest since they occur naturally in environments with excess toxic ions. The cyanobacterium Halothece sp. PCC 7418 (hereafter referred to as Halothece) exhibits remarkable halotolerance and was used to examine stress-responsive regulatory mechanisms. The effects of temperature on Halothece transcriptomes were examined using RNA sequencing.
