TABLE 4.

Effect of different initial pH values on CGP content in E. coli DH1(pMa/c5-914::cphA₆₈₀₃)

Initial pHa	Final pHb	Cell density (g CDM/liter)	CGP content of cells (% of CDM)
5.5	5.58	0.97 ± 0.07	13.9 ± 0.80
6.0	7.90	2.44 ± 0.08	15.7 ± 2.07
6.5	8.10	2.69 ± 0.08	25.9 ± 0.80
7.0	8.31	2.96 ± 0.01	25.4 ± 1.70
7.5	8.50	3.19 ± 0.02	27.2 ± 3.30
8.0	8.50	3.08 ± 0.02	25.9 ± 4.40

^aCells of E. coli DH1(pMa/c5-914::cphA₆₈₀₃) were grown in 250-ml Erlenmeyer flasks without baffles which contained 100 ml 6% (vol/vol) protamylasse supplemented with 100 μg/ml ampicillin. The initial pH was adjusted with 10 M NaOH before sterilization, and the flasks were incubated at 37°C for 44 h. Cells were harvested at the end of cultivation period and analyzed for CGP content, and the cell dry mass was determined. Data shown represent mean values and standard deviations of three independent experiments.

^bFinal pH values were measured in the supernatant at the end of the cultivation period.