TABLE 2.
Mutational analysis and fermentation profiles of anaerobically adapted ΔptsG ΔmanX and ΔptsI mutants.
|
Metabolites (mM) |
||||||||||
| Strain | Genotype | Fermentation time (h)a | OD600nm | Residual D-glucoseb | Acetate | Ethanol | Formate | Lactate | Succinate | Succinate ratioc (fold) |
| BW25113 | Wild-type | 6 | 5.63 ± 0.13 | NDd | 38.6 ± 0.2 | 36.4 ± 0.3 | 73.1 ± 0.1 | 10.3 ± 0.1 | 6.0 ± 0.0 | 0.04 (1.0) |
| HK907 | ΔptsG ΔmanX | 84 | 3.40 ± 0.05 | 3.9 ± 0.7 | 41.5 ± 0.1 | 17.5 ± 0.6 | 55.9 ± 0.7 | ND | 28.6 ± 1.3 | 0.29 (8.0) |
| HK953 | ΔptsG ΔmanX exuR G500A (W167Z) | 36 | 4.26 ± 0.46 | 3.1 ± 0.0 | 32.0 ± 0.2 | 21.4 ± 0.2 | 28.4 ± 0.4 | ND | 33.3 ± 0.3 | 0.27 (7.3) |
| HK954 | ΔptsG ΔmanX exuR T467A (L159Q) | 36 | 4.42 ± 0.14 | 2.9 ± 0.1 | 34.1 ± 0.8 | 21.5 ± 1.0 | 34.2 ± 2.1 | ND | 32.4 ± 0.5 | 0.27 (7.4) |
| HK955 | ΔptsG ΔmanX exuR:IS30 | 36 | 4.03 ± 0.18 | 3.0 ± 0.0 | 33.7 ± 0.7 | 22.5 ± 0.5 | 32.6 ± 2.8 | ND | 32.7 ± 0.7 | 0.28 (7.6) |
| HK956* | ΔptsG ΔmanX exuR 5 bp deletion after T431 | 36 | 3.90 ± 0.36 | 2.9 ± 0.0 | 33.5 ± 0.3 | 22.5 ± 1.0 | 31.4 ± 1.8 | ND | 33.3 ± 0.4 | 0.27 (7.4) |
| HK957 | ΔptsG ΔmanX exuR:IS60 (1226 bp) after C360 | 36 | 4.11 ± 0.17 | 2.8 ± 0.0 | 34.0 ± 0.8 | 22.7 ± 0.8 | 33.1 ± 2.3 | ND | 33.1 ± 0.3 | 0.27 (7.4) |
| HK958 | ΔptsG ΔmanX exuR T167A (L56Q) | 36 | 4.34 ± 0.15 | 3.0 ± 0.2 | 33.7 ± 0.5 | 22.6 ± 0.1 | 32.1 ± 1.4 | ND | 33.1 ± 0.3 | 0.28 (7.5) |
| HK966 | ΔptsG ΔmanX ΔexuR | 36 | 4.24 ± 0.31 | 3.5 ± 0.3 | 34.7 ± 2.9 | 20.6 ± 0.7 | 36.1 ± 8.1 | ND | 33.6 ± 1.6 | 0.27 (7.4) |
| HK898 | ΔptsI | 102 | 2.63 ± 0.20 | 5.6 ± 1.9 | 36.6 ± 1.5 | 8.2 ± 3.7 | 36.7 ± 5.4 | ND | 37.2 ± 3.1 | 0.32 (8.6) |
| HK947 | ΔptsI exuR C304T (Q102Z) | 54 | 2.55 ± 0.08 | 5.3 ± 0.1 | 31.8 ± 0.8 | 6.9 ± 0.4 | 21.1 ± 2.4 | ND | 41.2 ± 0.5 | 0.41 (11.2) |
| HK949* | ΔptsI exuR 127bp deletion after A531 | 54 | 2.62 ± 0.07 | 6.0 ± 0.2 | 36.2 ± 0.1 | 6.4 ± 0.6 | 34.6 ± 0.5 | ND | 38.2 ± 0.2 | 0.37 (10.1) |
| HK950 | ΔptsI exuR:IS1 (777 bp) after A171 | 54 | 2.76 ± 0.17 | 5.9 ± 0.5 | 32.9 ± 2.6 | 5.9 ± 0.4 | 24.4 ± 7.9 | ND | 40.8 ± 1.8 | 0.46 (12.6) |
| HK952 | ΔptsI exuR:IS5 (1200 bp) after G616 | 54 | 2.69 ± 0.05 | 3.8 ± 0.1 | 31.9 ± 0.5 | 4.9 ± 0.8 | 15.2 ± 1.7 | ND | 48.1 ± 0.9 | 0.49 (13.2) |
| HK971 | ΔptsI ΔexuR | 54 | 2.76 ± 0.23 | 3.9 ± 0.2 | 31.7 ± 0.1 | 7.9 ± 0.4 | 13.5 ± 0.3 | ND | 48.6 ± 0.5 | 0.48 (13.1) |
*Whole genomic sequencing was performed. aFermentation time (h) when glucose was completely consumed. bResidual D-glucose concentration. 50 mM glucose was added initially in the fermentation medium. cCalculated as succinic acid/(succinate + lactate + formate + acetate + ethanol). dND, not detected.