Progress and perspective on cyanobacterial glycogen metabolism engineering

Area of Science:

• Microbiology
• Synthetic Biology
• Metabolic Engineering

Background:

• Cyanobacteria are key oxygenic photoautotrophs and valuable microbial chassis for photosynthetic biomanufacturing.
• Metabolic engineering strategies aim to redirect carbon and energy flow towards desired metabolite synthesis in cyanobacterial cell factories.
• Glycogen metabolism, a crucial carbon sink and energy reserve from the Calvin-Benson-Bassham (CBB) cycle, is a primary target for optimization.

Purpose of the Study:

• To review the engineering efforts and physiological effects of modifying glycogen metabolism in cyanobacteria.
• To evaluate the impact of glycogen metabolism engineering on cyanobacterial chassis strains and cell factories for biomanufacturing.
• To provide perspectives on controlling carbon and energy flow for improved biomanufacturing.

Main Methods:

• Review of synthetic biology and metabolic engineering approaches applied to cyanobacterial glycogen metabolism.
• Analysis of studies investigating the regulation of glycogen synthesis and storage.
• Examination of research on the consequences of disturbed glycogen metabolism on cellular functions.

Main Results:

• Engineering glycogen metabolism can successfully regulate its synthesis and storage in cyanobacteria.
• Disturbing glycogen metabolism often leads to compromised cellular physiology and reduced metabolic robustness.
• The efficacy of glycogen removal strategies for enhancing photosynthetic biosynthesis remains a subject of debate.

Conclusions:

• Glycogen metabolism engineering in cyanobacteria presents a double-edged sword, offering control but risking physiological impairment.
• Further research is needed to balance glycogen manipulation with maintaining cellular robustness for effective biomanufacturing.
• Novel strategies are required for precise control over carbon and energy flux in engineered cyanobacterial systems.