Reprogramming yeast metabolism for customized starch-rich micro-grain through low-carbon microbial manufacturing.

Area of Science:

• Biotechnology
• Synthetic Biology
• Metabolic Engineering

Background:

• Starch is a vital food ingredient and industrial material.
• Current starch production relies on agriculture, demanding arable land and resources.
• Low-carbon microbial manufacturing presents a sustainable, land-independent alternative.

Purpose of the Study:

• To engineer oleaginous yeast for efficient starch production using a low-carbon feedstock.
• To enhance starch yield and productivity beyond conventional methods.
• To establish a customizable platform for microbial starch synthesis.

Main Methods:

• Rewiring of starch biosynthesis and gluconeogenesis pathways in yeast.
• Regulation of yeast cell morphology for micro-grain formation.
• Utilizing electro-synthesized acetate derived from CO2 as a substrate.

Main Results:

• Engineered yeast accumulated starch at 47.18% of dry cell weight.
• Achieved spatial-temporal starch productivity of 243.7 g/m²/d, 50-fold higher than crop cultivation.
• Demonstrated volumetric productivity of 160.83 mg/L/h, an order of magnitude higher than other microbial systems.
• Showcased tunable starch composition and starch-protein ratios.

Conclusions:

• The engineered yeast efficiently converts CO2-derived acetate into high-yield starch.
• This microbial platform offers superior productivity and customization for starch manufacturing.
• The approach advances low-carbon nutritional manufacturing and biomass conversion.