Parameter | Production rate | Specific production rate | Yielda (H2 mmol/CO mmol) | Aerobic growth phase | |||
---|---|---|---|---|---|---|---|
Maximum (mmol/h) | Time (h) | Maximum (mmol/h * OD600) | Time (h) | ∆OD600 (t12 − t0) | µ (1/h) | ||
Control: 60 °C; pH 7.0; 0.04 mM Fe2+; no Ni2+; 50% CO; 12 h pre-culture; 2% inoculum | 0.094 ± 0.016 | 35–48 | 0.163 ± 0.054 | 35–48 | 0.763 ± 0.026 | 0.467 ± 0.073 | 0.14 |
50 °C | 0.055 ± 0.027 | 73–82 | 0.144 ± 0.06 | 73–82 | 0.698 ± 0.068 | 0.647 ± 0.044 | 0.163 |
55 °C | 0.098 ± 0.006 | 34–48 | 0.124 ± 0.001 | 34–48 | 0.783 ± 0.014 | 0.716 ± 0.059 | 0.172 |
pH 5.5 | 0.06 ± 0.025 | 72–82 | 0.358 ± 0.103 | 72–82 | 0.606 ± 0.168 | 0.127 ± 0.035 | 0.128 |
pH 8.5 | 0.122 ± 0.005 | 59–72 | 0.294 ± 0.028 | 59–72 | 0.786 ± 0.018 | 0.348 ± 0.006 | 0.127 |
0.3 mM NiSO4·6H2O + 0.04 mM FeSO4·7H2O | 0.078 ± 0.015 | 48–58 | 0.192 ± 0.035 | 48–58 | 0.716 ± 0.032 | 0.36 ± 0.056 | 0.122 |
0.08 mM FeSO4·7H2O | 0.115 ± 0.020 | 25–35 | 0.24 ± 0.052 | 25–35 | 0.782 ± 0.012 | 0.442 ± 0.052 | 0.127 |
36:64 CO:air | 0.073 ± 0.006 | 34–48 | 0.104 ± 0.016 | 34–48 | 0.748 ± 0.006 | 0.256 ± 0.042 | 0.095 |
75:25 CO:air | 0.138 ± 0.009 | 34–48 | 0.351 ± 0.038 | 34–48 | 0.807 ± 0.022 | 0.136 ± 0.083 | 0.064 |
4 h pre-culture | 0.129 ± 0.018 | 35–49 | 0.303 ± 0.046 | 35–49 | 0.796 ± 0.029 | 0.491 ± 0.015 | 0.372 |
24 h pre-culture | 0.115 ± 0.025 | 34–48 | 0.27 ± 0.098 | 34–48 | 0.779 ± 0.013 | 0.316 ± 0.027 | 0.132 |
10% inoculum | 0.101 ± 0.022 | 25–35 | 0.137 ± 0.025 | 25–35 | 0.806 ± 0.025 | 0.425 ± 0.063 | 0.052 |
20% inoculum | 0.068 ± 0.023 | 59–73 | 0.108 ± 0.029 | 59–73 | 0.741 ± 0.028 | 0.151 ± 0.131 | 0.013 |
Combined: 55 °C, pH 7.0, 0.08 mM Fe2+, no Ni2+, 75% CO; 4 h pre-culture; 10% inoculum | 0.182 ± 0.009 | 34–58 | 0.566 ± 0.024 | 34–58 | 0.808 ± 0.01 | 0.323 ± 0.02 | 0.32 |