TABLE 3.

Origin of metabolic intermediates in glucose (C)- and ammonia (N)-limited chemostat cultures as determined by METAFoR analysis^a

Metabolite	% of total pool in strain and chemostat conditions (D, h−1):
	E. coli JM101			E. coli PB25
	C-limited (0.09)	C-limited (0.40)	N-limited (0.09)	C-limited (0.08)	C-limited (0.40)	N-limited (0.08)
P5P from G6P (lb)	9 ± 2	12 ± 2	0 ± 2	1 ± 2	14 ± 2	1 ± 2
P5P from T3P + C2	91 ± 2	88 ± 2	100 ± 2	99 ± 2	86 ± 2	99 ± 2
P5P from E4P	35 ± 2	21 ± 2	32 ± 2	26 ± 2	22 ± 2	23 ± 2
E4P from F6P (lb)	10 ± 4	26 ± 4	17 ± 4	39 ± 4	23 ± 4	n.d.b
PEP via transketolase (ub)	66 ± 11	31 ± 7	1 ± 7	41 ± 19	37 ± 8	26 ± 20
OAA from PEP	36 ± 2	38 ± 1	38 ± 7	71 ± 2	54 ± 2	85 ± 3
PEP from OAA	16 ± 4	7 ± 4	15 ± 5	38 ± 7	15 ± 2	4 ± 13
PYR from MAL (lb)	5 ± 2	4 ± 2	10 ± 2	25 ± 2	13 ± 2	9 ± 3
PYR from MAL (ub)	7 ± 3	6 ± 3	16 ± 3	85 ± 9	29 ± 4	59 ± 20
ACA from PYR	>98	>98	>95	>95	>98	88 ± 2
OGA from OAA	>95	>94	>93	>96	>95	>99
ICT from SUC + GOX	0 ± 7	0 ± 6	2 ± 7	0 ± 4	0 ± 4	6 ± 4
OAA exchanged to FUM	50 ± 22	69 ± 12	51 ± 12	68 ± 13	73 ± 10	50 ± 7
SER from GLY + C1	42 ± 2	21 ± 2	31 ± 3	41 ± 3	23 ± 2	39 ± 3
GLY from CO2 + C1	1 ± 3	1 ± 3	5 ± 3	0 ± 3	0 ± 3	5 ± 4

^aFor abbreviations, see Fig. 2 legend. lb, lower bound; ub, upper bound; ICT, isocitrate; SUC, succinate; GOX, glyoxylate; SER, serine; GLY, glycine.

^bn.d., not determined.