Skip to main content

Table 3 Fermentation balances of carbohydrates by Caldicellulosiruptor sp. str. DIB 004C, Thermoanaerobacter sp. strain DIB 097X and co-cultures of the strains DIB 004C and DIB 097X on glucose, Avicel, washed pretreated poplar and washed pretreated miscanthus

From: Single-step ethanol production from lignocellulose using novel extremely thermophilic bacteria

Growth on glucose
Culture Glucose initial Glucose consumed Ethanol Acetate Lactate CO2 H2 Cell dry weight Cell dry weight Carbon in consumed glucose Carbon found in products and cells Carbon recovery Electron recovery     
mM mM mM mM mM mM mM mM carbon g/l mM mM % %     
Strain DIB 004C 55.51 30.6 ± 2.8 5.5 ± 1.0 21.9 ± 2.6 35.3 ± 5.5 8.8 ± 7.4 20.8 ± 12.1 9.7 ± 1.9 0.25 ± 0.05 183.8 ± 16.9 179.3 ± 20.2 98.9 ± 18.2 103.8 ± 18.3     
Strain DIB 097X 55.51 55.4 ± 0.4 53.1 ± 7.6 5.3 ± 0.6 55.6 ± 4.9 9.5 ± 13.3 2.4 ± 1.3 14.4 ± 0.1 0.37 ± 0.00 332.0 ± 2.2 307.4 ± 29.5 92.5 ± 8.5 107.9 ± 10.7     
Growth on Avicel
Culture Avicel initial Avicel final Avicel consumed Glucose equivalents initial Glucose equivalents consumed Ethanol Acetate Lactate CO2 H2 Cell dry weight Cell dry weight Carbon in consumed glucose equivalents Carbon found in products and cells Carbon recovery Electron recovery Consumption of cellulose in Avicel (100% = 61,7 mM glucose equivalents consumed)
  g/l g/l g/l mM mM mM mM mM mM mM mM carbon g/l mM mM % % %
Strain DIB 004C 10.00 5.88 ± 0.02 4.12 ± 0.02 61.68 25.4 ± 0.1 4.8 ± 0.9 11.6 ± 2.1 30.4 ± 4.8 9.1 ± 6.3 10 ± 3.4 9.3 ± 1.3 0.24 ± 0.03 152.6 ± 0.6 142.3 ± 17.6 93.2 ± 11.5 103.0 ± 10.3 41.2 ± 0.2
Strain DIB 004C + strain DIB 097X 10.00 6.34 ± 0.02 3.66 ± 0.02 61.68 22.6 ± 0.1 6.2 ± 0.4 10.3 ± 1.9 25.7 ± 3.8 12.6 ± 3.6 9.2 ± 2.4 7.5 ± 1.1 0.19 ± 0.03 135.4 ± 0.6 130.1 ± 14.7 96.1 ± 10.8 105.0 ± 2.6 36.6 ± 0.2
Growth on washed pretreated poplar
Culture Poplar initial Poplar final Poplar consumed Glucose equivalents initial Glucose equivalents consumed Ethanol Acetate Lactate CO2 H2 Cell dry weight Cell dry weight Carbon in consumed glucose equivalents Carbon found in products and cells Carbon recovery Electron recovery Consumption of cellulose in poplar (100% = 21.7 mM glucose equivalents consumed)
  g/l g/l g/l mM mM mM mM mM mM mM mM carbon g/l mM mM % % %
Strain DIB 004C 6.05 4.80 ± 0.43 1.48 ± 0.76 21.70 9.1 ± 4.7 0.2 ± 0.2 13.3 ± 2.2 7.5 ± 0.6 5.1 ± 4.3 8.1 ± 3.1 11.6 ± 0.0 0.30 ± 0.0 54.7 ± 28.0 65.9 ± 6.6 120.6 ± 12.0 137.8 ± 58.1 42.0 ± 21.5
Strain DIB 004C+ strain DIB 097X 6.05 4.21 ± 0.57 1.84 ± 0.57 21.70 11.3 ± 3.5 3.2 ± 1.9 13.2 ± 3.3 6.3 ± 4.0 5.7 ± 5.0 11.0 ± 4.7 10.2 ± 0.1 0.26 ± 0.0 68.0 ± 21.0 67.5 ± 16.8 99.3 ± 24.8 106.5 ± 24.4 52.2 ± 16.2
Growth on washed pretreated miscanthus
Culture Miscanthus initial Miscanthus final Miscanthus consumed Glucose equivalents initial Glucose equivalents consumed Ethanol Acetate Lactate CO2 H2 Cell dry weight Cell dry weight Carbon in consumed glucose equivalents Carbon found in products and cells Carbon recovery Electron recovery Consumption of cellulose in miscanthus (100% = 21.8 mM glucose equivalents consumed)
  g/l g/l g/l mM mM mM mM mM mM mM mM carbon g/l mM mM % % %
Strain DIB 004C 6.09 4.14 ± 0.03 1.95 ± 0.03 21.80 12.0 ± 0.2 2.7 ± 2.3 11.6 ± 1.9 6.3 ± 1.3 4.4 ± 4.7 7.2 ± 5.7 8.9 ± 1.7 0.23 ± 0.04 72.1 ± 1.2 64.6 ± 10.8 89.6 ± 15.0 94.6 ± 17.8 55.1 ± 0.9
Strain DIB 004C + strain DIB 097X 6.09 4.08 ± 0.08 2.01 ± 0.08 21.80 12.4 ± 0.5 5.2 ± 1.8 13.0 ± 1.5 5.5 ± 1.0 4.0 ± 1.9 9.8 ± 1.9 8.4 ± 2.1 0.22 ± 0.05 74.5 ± 2.9 69.2 ± 4.6 92.9 ± 6.1 102.3 ± 6.4 57.0 ± 2.2
  1. Fermentations were performed in 240 ml flasks containing 100 ml cultures with glucose, Avicel, washed pretreated poplar or washed pretreated miscanthus as substrates. Cultures were incubated at 72°C and 100 rpm for 41 h (glucose), 64 h (Avicel) and 400 h (poplar and miscanthus). Initial substrate concentrations were: 10 g/l (55.5 mM) of glucose; 10 g/l (61.7 mM glucose equivalents) of Avicel; 6.05 g/l dry material (21.7 mM glucose equivalents, 00.0 mM xylose equivalents, 0.1 mM galactose equivalents) of washed poplar; 6.09 g/l dry material (21.8 mM glucose equivalents, 1.1 mM xylose equivalents, 0.0 mM galactose equivalents) of washed miscanthus. Concentrations of carbohydrates in washed pretreated poplar and miscanthus were determined according to the standard procedure from NREL [24].
  2. Carbon balances presented in Table 3 were determined by measurements of initial and final carbohydrate concentrations and final carbon-containing end products, including cell dry weight by using the general empirical formula for cell composition of CH2N0.25O0.5[19, 32]. For washed pretreated poplar and miscanthus the loss of weight was attributed to the consumption of cellulose, since no xylose was detected in these substrates. Carbon contained in yeast extract and extracellular protein was not included in the carbon recovery. Carbon and electron balances were calculated as described [32].
  3. Data represent averages of the results of six replicate fermentation experiments.