Cell engineering of Escherichia coli allows high cell density accumulation without fed-batch process control.

Area of Science:

• Microbiology
• Biotechnology
• Metabolic Engineering

Background:

• Fed-batch cultivation is standard for high cell density in Escherichia coli.
• Controlling glucose uptake on the reactor level is complex.
• Acetic acid production during high-density growth inhibits cell viability.

Purpose of the Study:

• To engineer Escherichia coli strains for controlled glucose uptake at the cellular level.
• To achieve high cell density in batch cultures without acetic acid accumulation.
• To compare the performance of engineered strains with wild-type fed-batch cultures.

Main Methods:

• Mutations were introduced into the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) of Escherichia coli.
• Engineered strains were cultivated in batch mode to assess cell accumulation and growth rates.
• Performance was compared to wild-type fed-batch cultivation under controlled glucose feeding.

Main Results:

• Engineered strains exhibited controlled growth rates of 0.78, 0.38, and 0.25 h(-1) in batch culture.
• Batch cultivation of mutants yielded ten times more cells than wild-type fed-batch.
• Acetate production, oxygen consumption, and recombinant product formation were comparable to fed-batch conditions.

Conclusions:

• Cellular control of glucose uptake via PTS mutations offers a robust alternative to fed-batch cultivation.
• This approach facilitates high cell density production without acetic acid byproduct.
• The technique is suitable for high-throughput protein production and accelerated process development.