Table 7.
Comparative kinetics of isolates on switchgrass hydrolyzate SGH-N2 inoculated to A 620 = 8.4 +/− 2.5 a
| A. Volumetric rates during glucose or xylose consumption | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Adaptation stress | Isolate | Sugar uptake rate (g/L/h) | Ethanol productivity (g/L/h) | |||||||||
| Glucose | Xylose | Glucose | Xylose | Overall | ||||||||
| AFEX CSH | 33 | Colony 5 | 0.65 | A | 0.19 | D | 0.32 | A | 0.174 | A | 0.26 | A |
| AFEX CSH > E | 28 | 2A.1.53R-E30-C3 | 0.63 | A | 0.27 | B | 0.29 | A | 0.076 | C | 0.16 | D |
| AFEX CSH > E > PSGHL | 13 | 2A.1.53R S100E40-1 | 0.43 | C | 0.27 | B | 0.20 | C | 0.089 | C | 0.15 | E |
| AFEX CSH > E > PSGHL | 16 | 2A.1.53R-1 | 0.57 | AB | 0.23 | C | 0.27 | AB | 0.083 | C | 0.17 | D |
| PSGHL | 3 | Y-7124 S90E40-1 | 0.65 | A | 0.16 | E | 0.30 | A | 0.140 | B | 0.24 | B |
| PSGHL | 14 | Y-7124-6 | 0.62 | A | 0.24 | C | 0.28 | AB | 0.090 | C | 0.18 | C |
| PSGHL | 15 | Y-7124-10 | 0.63 | A | 0.20 | D | 0.30 | A | 0.066 | C | 0.16 | D |
| Wild | 1 | Y-7124 | 0.51 | B | 0.30 | A | 0.24 | B | 0.059 | C | 0.15 | E |
| B. Normalized rates per unit absorbance (620 nm) during glucose or xylose consumption | ||||||||||||
| Adaptation stress | Isolate | Sugar uptake rate (g/L/hA) | Ethanol productivity (g/L/hA) | |||||||||
| Glucose | Xylose | Glucose | Xylose | Overall | ||||||||
| AFEX CSH | 33 | Colony 5 | 0.060 | D | 0.017 | B | 0.029 | C | 0.0161 | B | 0.024 | B |
| AFEX CSH > E | 28 | 2A.1.53R-E30-C3 | 0.056 | D | 0.017 | B | 0.025 | CD | 0.0048 | DF | 0.012 | C |
| AFEX CSH > E > PSGHL | 13 | 2A.1.53R S100E40-1 | 0.040 | E | 0.019 | B | 0.018 | D | 0.0063 | CDF | 0.012 | C |
| AFEX CSH > E > PSGHL | 16 | 2A.1.53R-1 | 0.082 | C | 0.026 | A | 0.039 | B | 0.0094 | C | 0.022 | B |
| PSGHL | 3 | Y-7124 S90E40-1 | 0.152 | A | 0.025 | A | 0.072 | A | 0.0216 | A | 0.043 | A |
| PSGHL | 14 | Y-7124-6 | 0.057 | D | 0.016 | B | 0.026 | C | 0.0059 | CDF | 0.014 | C |
| PSGHL | 15 | Y-7124-10 | 0.089 | B | 0.023 | A | 0.042 | B | 0.0076 | CD | 0.020 | B |
| Wild | 1 | Y-7124 | 0.037 | E | 0.014 | B | 0.017 | D | 0.0028 | F | 0.009 | D |
| C. Yields and residuals per total initial sugar | ||||||||||||
| Adaptation stress | Isolate | Yields or residuals per total initial sugar (g/g) | ||||||||||
| Ethanol | Biomass | Xylitol | Residual xylose | |||||||||
| AFEX CSH | 33 | Colony 5 | 0.34 | A | 0.0030 | D | 0.025 | A | 0.055 | B | ||
| AFEX CSH > E | 28 | 2A.1.53R-E30-C3 | 0.34 | A | 0.0134 | B | 0.020 | A | 0.023 | C | ||
| AFEX CSH > E > PSGHL | 13 | 2A.1.53R S100E40-1 | 0.31 | B | 0.0067 | D | 0.024 | A | 0.060 | B | ||
| AFEX CSH > E > PSGHL | 16 | 2A.1.53R-1 | 0.34 | A | 0.0045 | D | 0.019 | A | 0.096 | A | ||
| PSGHL | 3 | Y-7124 S90E40-1 | 0.32 | B | 0.0060 | D | 0.023 | A | 0.113 | A | ||
| PSGHL | 14 | Y-7124-6 | 0.33 | AB | 0.0091 | C | 0.021 | A | 0.024 | C | ||
| PSGHL | 15 | Y-7124-10 | 0.33 | AB | 0.0050 | D | 0.029 | A | 0.073 | B | ||
| Wild | 1 | Y-7124 | 0.33 | AB | 0.0165 | A | 0.026 | A | 0.023 | C | ||
aWith the exception of xylitol yield, all parameters varied significantly among isolates based on one-way ANOVA (P < 0.001). Within columns, values with no letters in common are significantly different at P < 0.05 (Student-Newman-Keuls pairwise comparison method).