Xylose–glucose co-fermentation to ethanol by Escherichia coli strain MS04 using single- and two-stage continuous cultures under micro-aerated conditions

Table 1 Kinetic and stoichiometric parameters of ethanologenic E. coli MS04 in batch and SSCC under micro-aerated conditions in mineral medium supplemented with xylose (42.5 g/L), glucose (7.5 g/L), and sodium acetate (2 g/L)

Culture	D (h⁻¹)	μ (h⁻¹)	Ethanol (g_EtOH/L)	Y_PS (%, w/w)	Q_P (g_EtOH/L h)	q_P (g_EtOH/g_DCW h)	Y_XS (g_DCW/g_S)	Carbon balance (%)
Batch	–	0.46 ± 0.01	22.2 ± 0.09	87 ± 1.2	1.3 ± 0.05	1.38 ± 0.02	0.054 ± 0.001	91 ± 0.91
SSCC	0.05	0.05	18.2 ± 0.15	72 ± 0.6	0.9 ± 0.01	0.58 ± 0.03	0.032 ± 0.002	75 ± 0.55
SSCC	0.10	0.10	15 ± 0.4	82 ± 1	1.5 ± 0.04	0.81 ± 0.04	0.051 ± 0.002	91 ± 0.55
SSCC	0.15	0.15	10 ± 0.2	82 ± 2	1.5 ± 0.04	0.99 ± 0.02	0.064 ± 0.005	95 ± 1.3
SSCC	0.20	0.20	5.1 ± 0.2	77 ± 2	1.0 ± 0.04	1.04 ± 0.03	0.076 ± 0.003	96 ± 0.7
SSCC	0.30	0.30	1.8 ± 0.2	80 ± 2	0.53 ± 0.06	1.47 ± 0.02	0.087 ± 0.014	99 ± 0.5

Average values and standard errors are shown from duplicate experiments for batch cultures and triplicate measurements during the steady state of continuous cultures
D dilution rate, µ specific growth rate, Y_PS ethanol yield on sugars consumed as percentage of the maximum theoretical; Y_XS biomass yield on sugars consumed, Q_P volumetric ethanol productivity, q_P specific ethanol productivity

ISSN: 1475-2859