Continuous and batch cultures of Escherichia coli KJ134 for succinic acid fermentation: metabolic flux distributions and production characteristics

Table 2 Steady state results from continuous fermentations

Dilution rate	Effective glucose in feed^a	Glucose in effluent	SA in effluent	AcA in effluent	Form A in effluent	Malic acid in effluent	DCW	Mass Balance^b	SA/AcA	Y_SP^c	Y_SX	P
(h^-1)	(g L^-1)	(g L^-1)	(g L^-1)	(g L^-1)	(g L^-1)	(g L^-1)	(g L^-1)		(mol mol^-1)	(g g^-1)	(g g^-1)	(g L^-1h^-1)
0.056	19.0	2.2	12.9	2.9	0.3	0	ND^d	ND^d	2.3	0.77	ND	0.72
0.146	19.4	12.4	5.0	1.4	0.6	0.38	0.88	1.00	1.9	0.71	0.125	0.73
0.146	19.4	12.7	4.7	1.4	0.5	0.00	0.87	1.00	1.7	0.70	0.130	0.68
0.093	19.0	6.6	9.2	2.5	0.6	0.34	1.97	1.05	1.9	0.74	0.159	0.85
0.093	19.0	6.4	9.3	2.5	0.6	0.00	1.62	1.02	1.9	0.74	0.128	0.87
0.187	19.8	15.8	2.5	0.8	0.3	0.51	0.68	1.00	1.5	0.62	0.171	0.46
0.037	19.0	0.0	14.0	3.9	0.5	0	ND^d	ND^d	1.8	0.74	ND^d	0.52
0.060	49.4	33.9	11.9	3.0	0.5	0.44	1.21	0.99	2.0	0.77	0.078	0.71
0.060	49.2	33.9	11.5	3.0	0.3	0.00	1.21	1.00	2.0	0.75	0.079	0.69
0.093	48.9	39.0	7.0	1.8	0.3	0.37	0.76	0.98	2.0	0.70	0.077	0.65
0.093	49.0	39.6	6.3	1.7	0.4	0.37	1.01	0.98	1.9	0.67	0.107	0.59
0.043	47.9	30.3	13.4	3.5	0.3	0.00	1.41	0.99	2.0	0.76	0.080	0.58
0.043	48.3	30.7	13.3	3.6	0.3	0.54	1.41	0.99	1.9	0.76	0.081	0.57
0.021	47.3	23.5	18.0	4.7	0.8	0.49	1.45	0.98	2.0	0.76	0.061	0.38
0.021	47.3	22.8	17.3	4.4	0.3	0.60	1.53	0.94	2.0	0.71	0.063	0.36

^a The dilution effect of KOH dosing incorporated into an effective feed concentration.
^b Fraction of accounted mass in effluent (malic acid not used in calculation).
^c SA yield based on glucose consumed.
^d Not determined.

ISSN: 1475-2859