Project description:Sodium gradients in cyanobacteria play an important role in energy storage under photoautotrophic conditions but have not been well studied during autofermentative metabolism under the dark, anoxic conditions widely used to produce precursors to fuels. Here we demonstrate significant stress-induced acceleration of autofermentation of photosynthetically generated carbohydrates (glycogen and sugars) to form excreted organic acids, alcohols, and hydrogen gas by the halophilic, alkalophilic cyanobacterium Arthrospira (Spirulina) maxima CS-328. When suspended in potassium versus sodium phosphate buffers at the start of autofermentation to remove the sodium ion gradient, photoautotrophically grown cells catabolized more intracellular carbohydrates while producing 67% higher yields of hydrogen, acetate, and ethanol (and significant amounts of lactate) as fermentative products. A comparable acceleration of fermentative carbohydrate catabolism occurred upon dissipating the sodium gradient via addition of the sodium-channel blocker quinidine or the sodium-ionophore monensin but not upon dissipating the proton gradient with the proton-ionophore dinitrophenol (DNP). The data demonstrate that intracellular energy is stored via a sodium gradient during autofermentative metabolism and that, when this gradient is blocked, the blockage is compensated by increased energy conversion via carbohydrate catabolism.
Project description:Cultivating Limnospira maxima, renowned for its abundant proteins and valuable pigments, faces substantial challenges rooted in the limited understanding of its optimal growth parameters, associated high costs, and constraints in the procurement of traditional nitrogen sources, particularly NaNO3. To overcome these challenges, we conducted a comprehensive 4 × 3 factorial design study. Factors considered included white, red, blue, and yellow light spectra, along with nitrogen sources NaNO3 and KNO3, as well as a nitrogen-free control, for large-scale implementation. Optimal growth, measured by Optical Density, occurred with white and yellow light combined with KNO3 as the nitrogen source. These conditions also increased dry weight and Chl-a content. Cultures with nitrogen deprivation exhibited high values for these variables, attributed to carbon accumulation in response to nitrogen scarcity. Phycocyanin, a crucial pigment for nutrition and industry, reached its highest levels in cultures exposed to white light and supplemented with KNO3, with an impressive content of 384.11 g kg-1 of dry weight. These results highlight the efficacy and cost-efficiency of using a combination of white light and KNO3 for large-scale L. maxima cultivation. This strategy offers promising opportunities to address global food security challenges and enhance the production of industrially relevant pigments.
Project description:Regenerative life support systems for space crews recycle organic and inorganic waste into water, food and oxygen using different organisms. For instance, the European Space Agency's MELiSSA uses Limnospira indica PCC8005 for air revitalisation and food production. Before use in space, the components' compatibility with reduced gravity must be tested. This innovative study introduces a novel ground analog designed specifically for microgravity experiments involving cyanobacteria, employing a cutting-edge random positioning machine (RPM). Limnospira indica PCC8005 was shown to grow slower under simulated microgravity and whole proteome analysis revealed a downregulation of e.g. ribosomal proteins, glutamine synthase and nitrate uptake transporters while an upregulation was found for gas vesicle proteins, carboxysome proteins and phycobiliproteins. All together our results suggested that L. indica experienced carbon limitation when cultivated in simulated microgravity conditions.
2024-12-19 | PXD045600 | Pride
Project description:Draft Genomes of Filamentous Cyanobacteria
Project description:Copper (Cu) is an essential trace element required for mitochondrial respiration. We show that Cu drives coordinated metabolic remodeling of bioenergy, biosynthesis and redox homeostasis and progression of clear cell renal cell carcinoma (ccRCC). Cu stimulates tumor growth. Late-stage ccRCCs accumulate Cu and allocate it to cytochrome c oxidase stimulating bioenergy production. Cu induces TCA cycle-dependent oxidation of glucose and its utilization for biosynthesis of a glutathione pool that protects against H2O2 generated during mitochondrial respiration, therefore coordinating bioenergy production with redox protection.
Project description:Copper (Cu) is an essential trace element required for mitochondrial respiration. We show that Cu drives coordinated metabolic remodeling of bioenergy, biosynthesis and redox homeostasis and promotes tumor growth and progression of clear cell renal cell carcinoma (ccRCC). Late-stage ccRCCs accumulate Cu and allocate it to cytochrome c oxidase stimulating bioenergy production. Cu induces TCA cycle-dependent oxidation of glucose and its utilization for biosynthesis of a glutathione pool that protects against H2O2 generated during mitochondrial respiration, therefore coordinating bioenergy production with redox protection. Single cell transcriptomics determined induction of mitochondrial electron transport chain, expression of NRF2 targets and glutathione biosynthesis, and decrease in HIF activity, the hallmark of ccRCC, during disease progression. Spatial transcriptomics identified that cancer cells with proliferative phenotype are embedded in clusters of cells with oxidative metabolism supporting effects of metabolic states on ccRCC progression. Our work establishes novel vulnerabilities with potential for therapeutic interventions in ccRCC.
2024-10-18 | GSE250163 | GEO
Project description:Bioenergy production from macroalgae