Table 1.
Glycerol consumption, product synthesis, and carbon recovery in cell mass and fermentation products during the microaerobic utilization of glycerol in minimal medium by wild-type and engineered strainsa
| Strain | Glycerol consumed (g/L) |
Product synthesized (g/L) |
Carbon recoveryb |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Acetate | Succinate | Ethanol | Lactate | Pyruvate | Biomass | Products | Overall | |||||
| Wild-type strain |
|
|||||||||||
| MG1655 |
19.1 (0.1) |
2.9 (0.1) |
2.4 (0.0) |
2.1 (0.1) |
1.6 (0.3) |
0.0 (0.0) |
1.2 (0.0) |
67.4 (1.4) |
75.4 (1.6) |
|||
| Strains engineered for the production of D-lactate |
|
|
|
|
||||||||
| LA01 |
18.2 (1.1) |
0.6 (0.1) |
0.0 (0.0) |
0.0 (0.0) |
12.3 (0.6) |
0.0 (0.0) |
1.4 (0.0) |
74.9 (3.4) |
84.3 (3.7) |
|||
| LA02 |
15.6 (1.8) |
0.6 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
10.9 (1.0) |
0.0 (0.0) |
1.2 (0.1) |
77.6 (2.8) |
87.4 (3.4) |
|||
| Strains engineered for the production of L-lactate |
|
|||||||||||
| LA06 |
11.0 (0.2) |
2.0 (0.1) |
0.1 (0.0) |
0.0 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
1.2 (0.0) |
27.8 (0.5) |
67.2 (0.9) |
|||
| LA07 |
9.8 (0.7) |
1.2 (0.4) |
0.2 (0.1) |
0.0 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
0.35 (0.1) |
20.7 (5.5) |
34.0 (2.2) |
|||
| LA06 (pZS) |
9.8 (0.1) |
1.8 (0.1) |
0.1 (0.0) |
0.0 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
1.1 (0.1) |
29.2 (1.6) |
70.0 (0.1) |
|||
| LA07 (pZS) |
9.9 (0.2) |
1.5 (0.0) |
0.3 (0.0) |
0.0 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
0.4 (0.0) |
30.1 (0.6) |
46.7 (2.0) |
|||
| LA06 (pZSldh) |
11.8 (0.1) |
0.6 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
6.4 (0.0) |
0.0 (0.0) |
1.3 (0.0) |
64.9 (0.2) |
78.6 (0.2) |
|||
| LA07 (pZSldh) |
10.9 (0.5) |
0.2 (0.0) |
0.1 (0.0) |
0.0 (0.0) |
6.7 (0.4) |
0.0 (0.0) |
0.3 (0.1) |
65.7 (2.9) |
70.4 (1.9) |
|||
| LA19 |
16.2 (0.2) |
1.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
9.1 (0.1) |
0.0 (0.0) |
0.9 (0.1) |
67.4 (0.2) |
74.5 (1.1) |
|||
| LA20 |
15.4 (0.1) |
0.4 (0.0) |
0.2 (0.0) |
0.0 (0.0) |
9.4 (0.1) |
0.0 (0.0) |
1.0 (0.1) |
67.7 (0.2) |
75.8 (0.5) |
|||
| LA19 (pZSKLMgldA) |
16.6 (0.6) |
1.0 (0.0) |
0.0 (0.0) |
0.2 (0.0) |
10.9 (0.4) |
0.0 (0.0) |
0.4 (0.0) |
79.0 (0.4) |
82.1 (0.9) |
|||
| LA19 (pZSglpKglpD) |
16.8 (0.9) |
0.7 (0.1) |
0.0 (0.0) |
0.0 (0.0) |
11.7 (1.2) |
0.0 (0.0) |
0.8 (0.0) |
79.7 (3.9) |
85.9 (3.8) |
|||
| LA19 (pZSldh) |
13.2 (1.6) |
0.6 (0.1) |
0.0 (0.0) |
0.0 (0.0) |
7.4 (1.3) |
0.0 (0.0) |
0.7 (0.1) |
65.6 (4.6) |
74.4 (3.4) |
|||
| LA20 (pZSKLMgldA) |
15.2 (0.3) |
0.4 (0.1) |
0.1 (0.0) |
0.0 (0.0) |
10.1 (0.5) |
0.0 (0.0) |
0.9 (0.2) |
72.9 (1.5) |
80.3 (3.1) |
|||
| LA20 (pZSglpKglpD) |
18.6 (0.4) |
0.6 (0.0) |
0.2 (0.0) |
0.0 (0.0) |
13.7 (0.7) |
0.0 (0.0) |
0.8 (0.0) |
76.4 (1.7) |
82.8 (1.6) |
|||
| LA20 (pZSldh) |
15.3 (0.2) |
0.2 (0.0) |
0.2 (0.1) |
0.0 (0.0) |
10.0 (0.1) |
0.0 (0.0) |
0.9 (0.0) |
70.5 (1.6) |
77.6 (2.0) |
|||
| LA20 (pZSglpK.glpD)c |
41.0 (0.0) |
1.0 (0.0) |
0.7 (0.0) |
0.0 (0.0) |
32.6 (0.1) |
0.0 (0.0) |
1.1 (0.0) |
86.4 (0.3) |
89.6 (0.3) |
|||
| LA20ΔlldD (pZSglpKglpD)c |
41.6 (0.0) |
0.8 (0.0) |
0.6 (0.0) |
0.0 (0.0) |
34.7 (0.0) |
0.0 (0.0) |
1.6 (0.0) |
90.3 (0.0) |
95.0 (0.1) |
|||
| LA20ΔlldD (pZSglpKglpD)d |
40.4 (0.0) |
0.9 (0.0) |
0.9 (0.0) |
0.0 (0.0) |
32.8 (0.1) |
0.0 (0.0) |
1.1 (0.0) |
88.4 (0.2) |
91.9 (0.1) |
|||
| LA20ΔlldD (pZSglpKglpD)e | 57.2 (0.0) | 1.6 (0.0) | 1.2 (0.0) | 0.0 (0.0) | 50.1 (0.0) | 0.0 (0.0) | 2.0 (0.0) | 95.2 (0.1) | 99.4 (0.7) | |||
a Data represent the average of three samples (standard deviations shown in parenthesis) taken from 36-hour shake flask cultures grown on minimal medium supplemented with 20 g/L of glycerol, unless otherwise specified.
b Carbon recovery is expressed as the percent mol of carbon in product, including biomass, per mol of carbon in glycerol consumed. The column “product” shows the total recovery of carbon in products, assuming that moles of acetate plus moles of ethanol equals moles of 1-C compounds (formate plus CO2) generated by the dissimilation of pyruvate. The column “overall” shows the overall carbon recovery, including products and biomass.
c Cultures in which 40 g/L of glycerol was used and samples were taken at 72 hours (all glycerol was consumed).
d A culture in which 40 g/L of crude glycerol derived from biodiesel production was used and samples were taken at 72 hours (all glycerol was consumed).
e A culture in which 60 g/L of crude glycerol (40 g/L initially present and 20 g/L added at 48 hours) was used and samples were taken at 84 hours (~ 57 g/L of glycerol were consumed).