Table 4.
Effects of synthetic inhibitor cocktails and sugarcane hydrolysate formulations supplied at different concentrations on the fermentation performance at 30°C of the newly isolated S. cerevisiae strain, Fm17, and the benchmark S. cerevisiae strain, 27P, when incubated in the presence of 100 g/l glucose and 50 g/l xylose a
| Strain | Inhibitor cocktail b | Highest ethanol concentration, g/l | YE/G, g/g | Q48h, g/l/h | q48h, g/g/h | YX/G, g/g | Glucose consumption rate at 48 h, g/l/h |
|---|---|---|---|---|---|---|---|
| Fm17 |
None |
49.4 |
0.49 (97%) |
0.88 |
0.34 |
0.027 |
1.73 |
| |
A |
48.6 |
0.49 (95%) |
1.01 |
0.31 |
0.030 |
2.07 |
| |
B |
47.9 |
0.48 (94%) |
1.00 |
0.30 |
0.031 |
2.06 |
| |
C |
47.1 |
0.47 (92%) |
0.87 |
0.31 |
0.030 |
1.89 |
| |
D |
19.0 |
0.46 (90%) |
0.07 |
0.11 |
0.009 |
0.24 |
| 27P |
None |
48.9 |
0.49 (95%) |
0.88 |
0.29 |
0.026 |
1.68 |
| |
A |
48.3 |
0.48 (95%) |
1.02 |
0.30 |
0.029 |
2.07 |
| |
B |
46.7 |
0.47 (92%) |
0.97 |
0.31 |
0.029 |
2.04 |
| |
C |
45.0 |
0.45 (88%) |
0.43 |
0.22 |
0.027 |
0.92 |
| |
D |
0.3 |
0.29 (58%) |
0.01 |
0.02 |
0.003 |
0.02 |
| Fm17 |
0% SH |
48.8 |
0.49 (96%) |
0.93c |
ND |
ND |
2.24c |
| |
25% SH |
47.6 |
0.47 (92%) |
1.02c |
ND |
ND |
2.38c |
| |
50% SH |
43.4 |
0.45 (89%) |
0.70c |
ND |
ND |
1.76c |
| |
75% SH |
18.6 |
0.42 (82%) |
0.22c |
ND |
ND |
0.53c |
| |
100% SH |
– |
– |
– |
– |
– |
– |
| 27P |
0% SH |
47.7 |
0.48 (94%) |
0.95c |
ND |
ND |
2.28c |
| |
25% SH |
44.0 |
0.44 (86%) |
1.04c |
ND |
ND |
2.38c |
| |
50% SH |
40.6 |
0.42 (83%) |
0.46c |
ND |
ND |
1.12c |
| |
75% SH |
2.4 |
0.24 (46%) |
0.03c |
ND |
ND |
0.19c |
| 100% SH | – | – | – | – | – | – |
ND, not determined; Q48h, volumetric productivity after 48 h; q48h, specific productivity after 48 h; SH, sugarcane hydrolysate; YE/G, ethanol yield per gram of consumed glucose calculated on the basis of the highest ethanol production (the percentage of theoretical maximum is indicated in brackets); YX/G, biomass yield after 72 hours on initial glucose.
aAll experiments were conducted in triplicate. Any standard deviations that were always less than 5% are not reported.
bThe combination of 100 g/l glucose and 50 g/l xylose was used to supplement YNB broth without inhibitors (reported in the table as ‘none’ or ‘0% SH’).
cParameter determined after 42 hours.