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

Svetlitchnyi, Vitali A; Kensch, Oliver; Falkenhan, Doris A; Korseska, Svenja G; Lippert, Nadine; Prinz, Melanie; Sassi, Jamaleddine; Schickor, Anke; Curvers, Simon

doi:10.1186/1754-6834-6-31

Biotechnology for Biofuels and Bioproducts

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
Culture	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

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].
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 CH₂N_0.25O_0.5[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].
Data represent averages of the results of six replicate fermentation experiments.

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