Enhanced production of γ-amino acid 3-amino-4-hydroxybenzoic acid by recombinant Corynebacterium glutamicum under oxygen limitation

Table 3 3-amino-4-hydroxybenzoic acid (3,4-AHBA) production from glucose by metabolically engineered strains of C. glutamicum

	Parent (KT01)	Δldh (HKC5037)	ΔpqoΔcatΔpta-ackA (HKC5052)	ΔalaTΔavtA^c (HKC5051)	Δmdh (HKC5057)
3,4-AHBA (g/L)^a	1.140 ± 0.085	1.950 ± 0.283	0.906 ± 0.199	1.190 ± 0.046	0.030 ± 0.017
Cell growth (g DCW/L)^a	7.2 ± 0.3	3.5 ± 0.5	2.9 ± 0.6	6.6 ± 0.9	2.8 ± 1.1
Specific productivity (mg/h/g DCW)^a	157.9 ± 5.7	561.7 ± 1.2	314.8 ± 31.5	183.3 ± 24.0	14.6 ± 15.1
Relative productivity (%)^b	100 ± 4	365 ± 1	205 ± 20	119 ± 16	10 ± 10
By-product
Lactate (g/L)^a	1.12 ± 0.35	N.D.	N.D.	0.54 ± 0.10	0.02 ± 0.01
Acetate (g/L)^a	2.88 ± 0.81	0.90 ± 0.49	0.81 ± 0.01	1.63 ± 0.22	N.D.
Succinate (g/L)^a	3.39 ± 0.28	N.D.	N.D.	0.39 ± 0.39	N.D.
Ala (g/L)^a	1.51 ± 0.07	0.54 ± 0.02	0.63 ± 0.02	0.21 ± 0.04	N.D.
Val (g/L)^a	0.92 ± 0.01	0.69 ± 0.07	0.66 ± 0.00	0.60 ± 0.11	N.D.
Lys (g/L)^a	1.30 ± 0.06	1.60 ± 0.18	2.86 ± 0.07	4.06 ± 0.08	2.55 ± 0.49
Total amounts of by-product (g/L)	11.12	3.73	4.96	7.43	2.57

N.D. not detected
^aValues were determined after 100 h of cultivation. Data are presented as the mean ± standard deviation calculated from the results of duplicate independent experiments. Specific productivity was determined based on dry cell weight (DCW) after 100 h of cultivation. All strains were grown under aerobic conditions until the late log phase in brain heart infusion medium, and the cultures were then inoculated at an initial OD₆₀₀ of 0.2 into modified mineral salt CGX II medium containing glucose (40 g/L) as the sole carbon source
^bRelative productivity was determined based on the specific productivity of 3,4-AHBA
^cFor 3,4-AHBA production, alanine (final 100 mg/L) was added to CGX II medium because this mutant required alanine for cell growth

ISSN: 1475-2859