Optimization of glucose feeding approaches for enhanced glucosamine and N-acetylglucosamine production by an engineered Escherichia coli.
In this work, a recombinant Escherichia coli was constructed by overexpressing glucosamine (GlcN) synthase and GlcN-6-P N-acetyltransferase for highly efficient production of GlcN and N-acetylglucosamine (GlcNAc). For further enhancement of GlcN and GlcNAc production, the effects of different glucose feeding strategies including constant-rate feeding, interval feeding, and exponential feeding on GlcN and GlcNAc production were investigated. The results indicated that exponential feeding resulted in relatively high cell growth rate and low acetate formation rate, while constant feeding contributed to the highest specific GlcN and GlcNAc production rate. Based on this, a multistage glucose supply approach was proposed to enhance GlcN and GlcNAc production. In the first stage (0-2 h), batch culture with initial glucose concentration of 27 g/l was conducted, whereas the second culture stage (2-10 h) was performed with exponential feeding at μ (set) = 0.20 h⁻¹, followed by feeding concentrated glucose (300 g/l) at constant rate of 32 ml/h in the third stage (10-16 h). With this time-variant glucose feeding strategy, the total GlcN and GlcNAc yield reached 69.66 g/l, which was enhanced by 1.59-fold in comparison with that of batch culture with the same total glucose concentration. The time-dependent glucose feeding approach developed here may be useful for production of other fine chemicals by recombinant E. coli.
Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
Xin
X
Chen
Long
L
Liu
Jianghua
J
Li
Jie
J
Liu
Guocheng
G
Du
Jian
J
Chen
D000117:Acetylglucosamine / Q000378:metabolism; D061249:Batch Cell Culture Techniques; D001709:Biotechnology; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D018014:Gene Transfer Techniques; D005944:Glucosamine / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D030781:Organisms, Genetically Modified; D014537:Uridine Diphosphate N-Acetylglucosamine
D014537:Uridine Diphosphate N-Acetylglucosamine; D005947:Glucose; D005944:Glucosamine; D000117:Acetylglucosamine