Engineering cyanobacteria for converting carbon dioxide into isomaltulose.

Area of Science:

• Biotechnology
• Metabolic Engineering
• Synthetic Biology

Background:

• Isomaltulose is a functional sweetener with significant food industry potential.
• Current production relies on sucrose isomerization, facing economic challenges from feedstock costs and purification.
• Cyanobacterial production offers a sustainable, carbon-negative approach using CO2 and solar energy.

Purpose of the Study:

• To engineer cyanobacteria for direct isomaltulose biosynthesis.
• To enhance isomaltulose production and secretion efficiency.
• To establish a novel CO2-driven route for functional sweetener manufacturing.

Main Methods:

• Genetic engineering of Synechococcus elongatus PCC 7942 with sucrose isomerases.
• Co-expression of Escherichia coli sucrose permease (CscB) for enhanced secretion.
• Cultivation and analysis of isomaltulose production titers.

Main Results:

• Successful synthesis and accumulation of isomaltulose in engineered cyanobacteria.
• Combinatorial expression of sucrose isomerases and CscB significantly increased isomaltulose titer.
• Achieved a production of 777 mg/L isomaltulose within a 6-day cultivation period.

Conclusions:

• Demonstrated a novel biosynthetic pathway for isomaltulose using cyanobacteria.
• Established a green production route for functional sweeteners from CO2.
• Provided insights into the metabolic engineering potential of cyanobacterial platforms.