Improved Bioproduction of 1-Octanol Using Engineered Synechocystis sp. PCC 6803

Area of Science:

• Synthetic Biology
• Metabolic Engineering
• Biotechnology

Background:

• 1-Octanol is a valuable chemical precursor for fuels, solvents, and fragrances.
• Cyanobacteria offer a sustainable platform for 1-octanol production using sunlight and CO2.
• Previous engineered strains exhibited low 1-octanol productivity.

Purpose of the Study:

• To improve the productivity of 1-octanol biosynthesis in engineered cyanobacteria.
• To identify and engineer more efficient thioesterases for 1-octanol production.
• To optimize cultivation conditions for enhanced 1-octanol yield and stability.

Main Methods:

• Engineered N-terminal truncations of plant thioesterases for improved activity and selectivity.
• Optimized inducer concentration and light intensity for cyanobacterial cultivation.
• Performed long-term cultivation and genetic stability assessments.

Main Results:

• Achieved up to 35% (w/w) carbon partitioning and 526 ± 5 mg/L 1-octanol titer in 12 days.
• Demonstrated stable strain maintenance for over 30 days and ten serial dilutions.
• Attained an accumulative titer of >3.5 g/L 1-octanol over 180 days under continuous culture.

Conclusions:

• Optimized thioesterases and environmental conditions significantly enhance 1-octanol productivity.
• The engineered cyanobacterial strain exhibits genetic stability and robust long-term performance.
• This work advances sustainable bioproduction of 1-octanol using engineered cyanobacteria.