Light-Harvesting Artificial Cells Containing Cyanobacteria for CO2 Fixation and Further Metabolism Mimicking

The bottom-up constructed artificial cells help to understand the cell working mechanism and provide the evolution clues for organisms. The energy supply and metabolism mimicry are the key issues in the field of artificial cells. Herein, an artificial cell containing cyanobacteria capable of light harvesting and carbon dioxide fixation is demonstrated to produce glucose molecules by converting light energy into chemical energy. Two downstream metabolic pathways starting from glucose molecules are investigated. One involves enzyme cascade reaction to produce H2O2 (assisted by glucose oxidase) first, followed by converting Amplex red to resorufin (assisted by horseradish peroxidase). The other pathway is more biologically relevant. Glucose molecules are dehydrogenated to transfer hydrogens to nicotinamide adenine dinucleotide (NAD(+)) for the production of nicotinamide adenine dinucleotide hydride (NADH) molecules in the presence of glucose dehydrogenase. Further, NADH molecules are oxidized into NAD(+) by pyruvate catalyzed by lactate dehydrogenase, meanwhile, lactate is obtained. Therefore, the cascade cycling of NADH/NAD(+) is built. The artificial cells built here pave the way for investigating more complicated energy-supplied metabolism inside artificial cells.

Automated summary

Bottom-up constructed artificial cells provide valuable insights into cell working mechanism and evolution of organisms. Energy supply and metabolism mimicry are key challenges in the field of artificial cells. In this study, an artificial cell containing cyanobacteria capable of light harvesting and carbon dioxide fixation is demonstrated to produce glucose molecules by converting light energy into chemical energy. Two downstream metabolic pathways starting from glucose molecules are investigated, offering potential for studying more complex energy-supplied metabolism inside artificial cells.