Advances in the study of the anabolic mechanism of blue bacteria sucrose.

Blue bacteria, also known as cyanobacteria or blue-green algae, are one of the oldest microorganisms on Earth.
they fix carbon dioxide and convert it into a variety of carbohydrates through plant-type photosynthesis.
study found that many blue bacteria synthesize and accumulate sucrose in cells in high-salt environments to resist adversity.
to use this physiological characteristics, the development of blue bacterial cell factory for the synthesis and secretion of sugar molecules, carbon dioxide and solar energy directly into sucrose products, is a potential new sugar raw material supply route.
the microbial metabolism engineering team of Qingdao Institute of Bioenergy and Process of the Chinese Academy of Sciences is working on the synthesis of blue bacterial sugars, and the team's recent research reveals a number of mechanisms in the regulation and metabolism of blue bacterial sucrose synthesis.
in response to the problem of the absence of seucrose synthesis transcription control protein Slr1588 whole gene and the insertion of two mutant strains inthem under salt stress conditions in the study of the previous cyanobacteria PCC 6803, the team systematically analyzed the phenotype of slr1588 and downstream ggp The structure and transcription of p gene prove that the transcription of the ggpP gene starts in the gene coding frame of slr1588, and the transcription inhibition of the downstream ggpP gene caused by the loss of the whole gene of slr1588 is the real cause of the salt-sensitive pheetype of the mutant strain.
based on the newly constructed slr1588 mutant strain, Slr1588 has been shown to regulate the transcription and sucrose decomposition enzyme activity of the sucrose synthesis key enzyme spsA gene.
the study provided a theoretical basis for further analysis of the blue bacteria sucrose synthesis regulation mechanism and targeted enhanced sucrose synthesis to increase sucrose production, the results of which were published in Frontiers in Microbiology.
In addition, the team made progress in the study of the anabolic mechanism of blue bacteria sucrose.
in blue bacteria, because sucrose synthesis and glycogen synthesis use the same precursor - glucose-1-phosphate, it is generally believed that there is a synthetic competitive relationship between the two, inhibiting glycogen synthesis will promote sucrose synthesis.
however, the team's findings are different.
the researchers used the ribosome switching strategy to achieve the gradient inhibition of glycogen synthesis in the polysphere PCC 7942 engineering strain, and found that the decrease in glycogen level did not lead to an increase in sucrose synthesis level, but reduced sucrose production, while the enhancement of glycogen synthesis in blue bacteria effectively increased the sucrose synthesis level.
studies have shown that glycogen synthesis is not a competitive pathway to the synthesis of blue bacteria sucrose, and is more likely to serve as a "carbon bank" to support sucrose synthesis (pictured).
the results of the study change the industry's traditional understanding of the relationship between glycogen synthesis and sucrose synthesis in blue bacteria, and provide a new modification strategy for further improving the production of genetically engineered blue bacteria sucrose.
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