biostudies-literatureUnknown11Song SBundesministerium für Bildung und ForschungThe introduction of alternative CO₂-fixing pathways in photoautotrophic organism may improve the efficiency of biological carbon fixation such as minimizing the carbon loss due to photorespiration. Here, we analyzed the effects of creating a formate entry point into the primary metabolism of the cyanobacterium <i>Synechocystis</i> sp. PCC 6803. The formate-tetrahydrofolate ligase (FTL) from <i>Methylobacterium extorquens</i> AM1 was expressed in <i>Synechocystis</i> to enable formate assimilation and reducing the loss of fixed carbon in the photorespiratory pathway. Transgenic strains accumulated serine and 3-phosphoglycerate, and consumed more 2-phosphoglycolate and glycine, which seemed to reflect an efficient utilization of formate. However, labeling experiments showed that tFrontiers in microbiology1650https://www.ebi.ac.uk/biostudies/studies/S-EPMC7372957biostudies-literatureExpression of Formate-Tetrahydrofolate Ligase Did Not Improve Growth but Interferes With Nitrogen and Carbon Metabolism of <i>Synechocystis</i> sp. PCC 6803.PMC7372957Brouwer EMHagemann MSong STimm SLindner SNReimann VHess WRfalseExpression of Formate-Tetrahydrofolate Ligase Did Not Improve Growth but Interferes With Nitrogen and Carbon Metabolism of <i>Synechocystis</i> sp. PCC 6803.The introduction of alternative CO₂-fixing pathways in photoautotrophic organism may improve the efficiency of biological carbon fixation such as minimizing the carbon loss due to photorespiration. Here, we analyzed the effects of creating a formate entry point into the primary metabolism of the cyanobacterium <i>Synechocystis</i> sp. PCC 6803. The formate-tetrahydrofolate ligase (FTL) from <i>Methylobacterium extorquens</i> AM1 was expressed in <i>Synechocystis</i> to enable formate assimilation and reducing the loss of fixed carbon in the photorespiratory pathway. Transgenic strains accumulated serine and 3-phosphoglycerate, and consumed more 2-phosphoglycolate and glycine, which seemed to reflect an efficient utilization of formate. However, labeling experiments showed that t2020-01-01T00:00:00Z20202026-04-20T03:11:05.757Z2020-11-19T13:35:04ZS-EPMC73729573276038710.3389/fmicb.2020.01650