Efficient 1,3-dihydroxyacetone biosynthesis in Gluconobacter oxydans using metabolic engineering and a fed-batch...

Area of Science:

• Biotechnology
• Industrial Microbiology

Background:

• 1,3-Dihydroxyacetone (DHA) is a valuable chemical with applications in cosmetics, pharmaceuticals, and food.
• Current industrial production relies on Gluconobacter oxydans, but requires process improvements for higher yields.

Purpose of the Study:

• To enhance the industrial production of 1,3-dihydroxyacetone (DHA).
• To identify and implement strategies for increasing DHA synthesis efficiency in Gluconobacter oxydans.

Main Methods:

• Screening of five industrial wild-type Gluconobacter strains to select the optimal producer (G. oxydans WSH-003).
• Individual knockout of 16 non-DHA synthesis-related dehydrogenase genes to identify beneficial mutations.
• Optimization of seed culture and fermentation media compositions.
• Implementation of a fed-batch fermentation system in a 5 L bioreactor.

Main Results:

• Selected G. oxydans WSH-003 strain showed superior DHA synthesis.
• One knockout strain significantly enhanced DHA production by 42.27% compared to the wild-type.
• Optimized media and fed-batch fermentation led to a final DHA concentration of 198.81 g L⁻¹.
• Achieved a high glycerol conversion rate of 82.84%.

Conclusions:

• Genetic modification of G. oxydans, specifically through targeted gene knockout, can significantly improve DHA production.
• Media optimization and advanced fermentation strategies are crucial for maximizing DHA yields.
• The developed process offers a highly efficient method for industrial DHA synthesis.