[Effects of nutrition condition on pcDNA3-HBS plasmid DNA production]

To investigate the effects of nutrition condition on plasmid DNA production, Escherichia coli JM109 containing plasmid pcDNA3S-HBA was grown in different culture media. Results show that carbon source, nitrogen source affected plasmid DNA yield significantly. Glucose and peptone was selected, since they were preferable to other investigated carbon source and nitrogen source. In M9P medium, the appropriate concentration of(NH4)2SO4 was important for plasmid DNA production, Gly, Asp, Gln were formulated into the M9G medium because they served as the nitrogen donors for nucleotides synthesis. With addition of 1.2 g/L Asp, 1.0 g/L Gln and 0.4 g/L Gly into M9G medium, plasmid DNA yield was 25 mg/L after 20 h culture. Foreign nucleotides distinctively affected plasmid DNA production. With addition of 0.4 g/L nucleosides mixture of thymidine and cytidine(moles fraction of thymidine:cytidine = 1:1) into M9P medium, plasmid DNA yield was 35 mg/L.