Table 5.
Laboratory evolution of xylose-fermenting strains of S. cerevisiae as tool for process intensification: comparison of key process parameters reported for the progenitor strain and the evolved strain, respectively
|
Progenitor strain - evolved strain |
Fermentation condition b | c Sugar (g/L) c | q Xylose (g/g CDW /h) | c Ethanol (g/L) d | Y Ethanol (g/g total sugars ) | μ max (h -1 ) e | Source |
|---|---|---|---|---|---|---|---|
| Genetic background a | |||||||
| TMB3001 - |
MM |
Glc: 50 |
0.08* |
22* |
0.38* |
0.44Glc |
[26] |
| TMB3001C1 |
AN |
Xyl: 50 |
0.31* |
28* |
0.40* |
0.44Glc |
|
|
XR/XDH/XK |
LCD |
|
(3.9–fold) |
(1.3–fold) |
(1.1–fold) |
(–) |
|
| H131-A3SB-2 - |
YE |
Xyl: 40 |
0.26 |
4* |
0.42 |
0.06Xyl |
[39] |
| H131-A3CS |
AN |
|
0.94 |
15* |
0.43 |
0.12Xyl |
|
|
XI/ PPP/ T |
LCD |
|
(3.6–fold) |
(3.8–fold) |
(–) |
(2–fold) |
|
| HDY.GUF5 - |
YE, Pep |
Glc: 36 |
0.13 |
18* |
0.23 |
n.a. |
[23] |
| GS1.11-26 |
Semi-AN |
Xyl: 37 |
1.10 |
34* |
0.46 |
n.a. |
|
|
XI/PPP |
HCD |
|
(8.5–fold) |
(1.9–fold) |
(1.8–fold) |
(–) |
|
| BP10001 - |
YE |
Xyl: 50 |
0.37 |
0.9 |
0.30 |
- |
This study |
| IBB10B05 |
AN |
|
1.04 |
2.8 |
0.31 |
0.02Xyl |
|
|
XR/XDH/XK |
LCD |
|
(2.8–fold) |
(3.1–fold) |
(–) |
(–) |
|
| TMB3400 - |
Wheat straw hydrolyzate, YE, salts, pH 5 |
Glc: 7.6 |
0.20* |
5.5 |
0.20 |
- |
[34] |
| KE6-13i |
AN |
Xyl: 38 |
0.04* |
6 |
0.27 |
- |
|
|
XR/XDH/XK |
HCD |
|
(-) |
(1.1–fold) |
(1.4–fold) |
(–) |
|
| TMB3400 - |
Spruce hydrolyzate, MM, pH 5 |
|
n.a. |
7.8* |
0.40 |
0.07Glc |
[24] |
| KE1-17 |
AN |
Glc: 18 |
n.a. |
7.9* |
0.43 |
0.08Glc |
|
|
XR/XDH/XK |
LCD |
Xyl: 9 |
(–) |
(–) |
(1.1–fold) |
(1.14–fold) |
|
| BP10001 - |
Wheat straw hydrolyzate, YE, pH 6.5 |
|
0.02 |
4 |
0.40 |
0.10Glc |
This study |
| IBB10B05 |
AN |
Glc: 32 |
0.35 |
21 |
0.39 |
0.19Glc |
|
| XR/XDH/XK | HCD | Xyl: 16 | (17.5–fold) | (5.3–fold) | (–) | (1.9–fold) |
aStrain background: PPP, overexpression of genes from the pentose phosphate pathway; T, overexpression of the HXT7 transporter; XDH, xylitol dehydrogenase; XI, xylose isomerase; XK, xylulose kinase; XR, xylose reductase. bAN, anaerobic; HCD, high cell density (start OD600 of fermentation ≥1); LCD, low cell density (start OD600 of fermentation ≤0.5); MM, mineral medium; Pep, peptone; YE, yeast extract. cInitial sugar concentration of the substrate. dEthanol produced within the first 50 h of fermentation or earlier, when sugars were depleted before. eMaximal growth rate on glucose (Glc) or xylose (Xyl). n.a., not analyzed; in parenthesis, improvement calculated from the evolved strain as compared to the progenitor strain; *Data are derived from the time courses given in the respective publications.