TABLE 3.
Growth properties of Methanothermobacter thermautotrophicus in the fed-batch fermentora
| Culture condition
|
Exponential phase
|
Linear phase
|
||||||
|---|---|---|---|---|---|---|---|---|
| vin (ml min−1) | Vol (liter) | Mode | μex (h−1) | qCH4 max (mol g−1 h−1) | ΔqCH4 (mol g−1 h−1) | YCH4 max (g mol−1 CH4) | pH2 lin (kPa) | YCH4 lin (g mol−1 CH4) |
| 107 | 2.5 | b | 0.25 | 0.167 | 0.079 | 3.15 | 1 | 3.00 |
| 214 | 2.5 | a | 0.22 | 0.144 | 0.070 | 3.15 | 1 | 3.20 |
| b | 0.24 | 0.127 | 0.034 | 7.05 | 4 | 2.20 | ||
| b | 0.25 | 0.161 | 0.037 | 6.75 | 4 | 2.00 | ||
| 428 | 2.5 | a | 0.23 | 0.174 | 0.034 | 6.70 | 6 | 1.70 |
| b | 0.23 | 0.177 | 0.035 | 6.70 | 29 | 1.65 | ||
| 2.0 | b | 0.22 | 0.178 | 0.033 | 6.70 | 49 | 1.55 | |
| 1.5 | b | 0.22 | 0.188 | 0.033 | 6.70 | 59 | 1.40 | |
M. thermautotrophicus was cultured at the indicated gassing rates and culture volumes. Abbreviations: vin, gassing rate (80% H2-20% CO2 [vol/vol]); μex, specific growth rate during exponential growth; qCH4 max, maximal specific methane-forming activity in the exponential phase; ΔqCH4, difference between the maximal and minimal specific methane-forming activity in the exponential phase; YCH4 max, theoretical maximal growth yield; pH2 lin, dissolved hydrogen partial pressure during linear growth; YCH4 lin, specific growth yield during linear growth. Modes: a, one impeller mounted; b, two impellers mounted. YCH4 max and YCH4 lin were calculated as specified in the text and in the supplemental material (1).