Combined 13C-assisted metabolomics and metabolic flux analysis reveals the impacts of glutamate on the central metabolism of high β-galactosidase-producing Pichia pastoris

Bioresources and Bioprocessing

Table 2 The pool size of intracellular organic acids and surge phosphates in P. pastoris GHL and G1HL

Metabolite	GHL (µmol/gDCW)	G1HL (µmol/gDCW)		G1HL/GHL (on Glc)	P value of T test	G1HL Glu + Glc/Glc	P value of T test
Metabolite	(Glc)	(Glc)	(Glc + Glu)	G1HL/GHL (on Glc)	P value of T test	G1HL Glu + Glc/Glc	P value of T test
G1P	0.86 ± 0.30	0.37 ± 0.08	0.32 ± 0.07	0.43	0.10	0.86	0.46
G6P	1.84 ± 0.53	1.18 ± 0.02	1.01 ± 0.24	0.64	0.16	0.86	0.34
F6P	1.15 ± 0.87	1.56 ± 0.02	0.02 ± 0.01	1.36	0.51	0.01	0.01
FBP	0.81 ± 0.16	0.86 ± 0.01	0.22 ± 0.01	1.06	0.64	0.26	0.00
M6P	0.03 ± 0.02	0.02 ± 0.01	0.07 ± 0.01	0.67	0.50	3.50	0.00
6PGA	0.68 ± 0.33	0.26 ± 0.02	0.43 ± 0.05	0.38	0.16	1.65	0.02
PEP	0.10 ± 0.01	0.08 ± 0.01	0.11 ± 0.02	0.80	0.07	1.38	0.10
PYR	1.02 ± 0.12	0.51 ± 0.01	1.63 ± 0.68	0.50	0.02	3.20	0.10
R5P	1.81 ± 0.94	2.65 ± 1.09	0.34 ± 0.15	1.46	0.37	0.13	0.06
RL5P	9.54 ± 0.97	7.04 ± 2.51	1.47 ± 0.50	0.74	0.22	0.21	0.06
S7P	4.64 ± 2.43	2.58 ± 0.76	2.26 ± 0.53	0.56	0.28	0.88	0.59
E4P	0.20 ± 0.02	0.16 ± 0.03	0.29 ± 0.53	0.80	0.14	1.81	0.01
αKG	0.35 ± 0.03	0.02 ± 0.01	0.57 ± 0.37	0.06	0.00	28.50	0.12
Cit	1.17 ± 0.16	0.89 ± 0.02	1.23 ± 0.39	0.76	0.09	1.38	0.27
Fum	0.21 ± 0.03	0.16 ± 0.08	0.61 ± 0.17	0.76	0.40	3.81	0.03
Mal	0.56 ± 0.61	0.49 ± 0.28	3.09 ± 0.85	0.88	0.87	6.31	0.02
Suc	0.59 ± 0.07	0.25 ± 0.17	1.02 ± 0.39	0.42	0.06	4.08	0.06

All detections were in triplicates. The significant levels of differences between GHL and G1HL grown on Glc, G1HL grown on Glc/Glu, and on Glc are evaluated by two-tailed T test