Constructing elongated Corynebacterium glutamicum and its application in efficient l-lysine production during...

Area of Science:

• Microbial Biotechnology
• Synthetic Biology
• Metabolic Engineering

Background:

• Biofilm formation is crucial for efficient bio-chemical production in continuous fermentation.
• Elongated cell morphology promotes cell attachment and aggregation, enhancing biofilm development.

Purpose of the Study:

• To investigate the effect of downregulating the cell division gene ftsZ on cell elongation and biofilm formation in Corynebacterium glutamicum.
• To evaluate the impact of the engineered strain on l-lysine production and physiological stability during continuous fermentation.

Main Methods:

• Constructed an elongated C. glutamicum strain (Cg-AsftsZ) by downregulating ftsZ expression.
• Performed biofilm-based continuous fermentation to assess l-lysine titer and yield.
• Analyzed physiological changes, including cell viability and DNA content, in biofilm cells.

Main Results:

• The Cg-AsftsZ strain achieved an average l-lysine titer of 143.3 g/L and a yield of 66.4% (l-lysine/glucose).
• This represents a 6.8% improvement in l-lysine yield compared to the wild-type strain.
• Biofilm cells of Cg-AsftsZ exhibited sustained high viability and DNA content, indicating robust metabolic stability.

Conclusions:

• Inhibiting ftsZ expression to create elongated cells in C. glutamicum effectively promotes biofilm formation.
• This strategy significantly enhances l-lysine yield during continuous fermentation.
• The findings offer valuable insights for developing advanced biofilm-based fermentation processes for bio-chemical production.