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 1 The pool sizes of intracellular amino acids 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
Ala	1.41 ± 0.07	0.54 ± 0.30	1.86 ± 0.01	0.38	0.03	3.44	0.02
Arg	77.32 ± 1.93	25.63 ± 3.30	56.59 ± 7.92	0.33	0.00	2.21	0.01
Asp	80.33 ± 2.75	53.57 ± 1.81	85.48 ± 3.47	0.67	0.00	1.60	0.00
Asn	2.62 ± 0.29	0.25 ± 0.03	2.09 ± 0.88	0.10	0.00	8.36	0.07
Gln	36.83 ± 1.67	5.76 ± 4.52	47.87 ± 6.46	0.16	0.00	8.31	0.00
Glu	62.57 ± 2.36	9.44 ± 7.16	91.63 ± 14.42	0.15	0.00	9.71	0.00
His	5.48 ± 0.19	0.66 ± 0.40	4.64 ± 0.42	0.12	0.00	7.03	0.00
Ile	0.97 ± 0.30	0.22 ± 0.04	1.08 ± 0.47	0.23	0.05	4.91	0.09
Orn	10.02 ± 0.28	0.95 ± 0.51	4.42 ± 1.14	0.09	0.00	4.65	0.02
Ser	7.58 ± 1.29	1.51 ± 0.95	7.26 ± 1.54	0.20	0.00	4.81	0.01
Thr	3.89 ± 0.05	0.73 ± 0.49	5.21 ± 1.09	0.19	0.01	7.14	0.01
Trp	0.75 ± 0.05	0.09 ± 0.05	1.24 ± 0.41	0.12	0.00	13.78	0.04
Val	1.91 ± 0.04	0.56 ± 0.23	2.13 ± 0.34	0.29	0.01	3.80	0.00
Leu	0.90 ± 0.27	0.21 ± 0.06	0.81 ± 0.25	0.23	0.04	3.86	0.05
Lys	3.62 ± 0.29	0.42 ± 0.17	2.51 ± 0.56	0.12	0.00	5.98	0.02
Met	0.55 ± 0.20	0.29 ± 0.03	0.65 ± 0.14	0.53	0.15	2.24	0.04
Phe	0.50 ± 0.24	0.17 ± 0.04	0.48 ± 0.20	0.34	0.14	2.82	0.11
Pro	9.24 ± 0.52	1.66 ± 1.38	13.22 ± 4.82	0.18	0.01	7.96	0.04
Total	306.48 ± 12.80	102.66 ± 21.46	329.16 ± 44.53	0.33	0.00	3.21	0.05

18 amino acids were detected. Samples were taken in the exponential growth phase, 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