Homofermentative production of optically pure L-lactic acid from xylose by genetically engineered Escherichia coli B

Table 1 Summary of xylose fermentations by E. coli WL204

Xylose (g L^-1)	Cell growth		Lactic acid		Volumetric productivity (g L^-1h^-1)		Specific productivity (g g^-1h^-1)		By-product (Acetic acid) (g L^-1)
Xylose (g L^-1)	Mass (g L^-1)	Rate¹⁾(h^-1)	Titer (g L^-1)	Yield²⁾(%)	Maximum³⁾	Average⁴⁾	Maximum³⁾	Average⁴⁾	By-product (Acetic acid) (g L^-1)
70 (LB)	1.619 ± 0.112	0.271 ± 0.032	62.04 ± 0.92	97	1.631 ± 0.039	0.780 ± 0.017	1.05 ± 0.032	0.623 ± 0.097	1.01 ± 0.383
100 (LB)	1.901 ± 0.110	0.291 ± 0.030	66.03 ± 1.51	90	1.934 ± 0.011	1.092 ± 0.010	1.02 ± 0.054	0.653 ± 0.052	0.992 ± 0.087
70 (NBS)	2.487 ± 0.150	0.205 ± 0.020	42.9 ± 0.80	91	0.768 ± 0.021	0.358 ± 0.012	0.309 ± 0.018	0.144 ± 0.010	0.596 ± 0.026

¹⁾ The growth rate was calculated from the log growth period (0 h to 12 h).
²⁾ The yield was calculated based on lactic acid produced over xylose metabolized.
³⁾ The maximum productivity was calculated from the fastest 24 h fermentation period (6 h to 30 h for both 70 g L^-1 and 100 g L^-1 xylose LB medium; 0 h to 24 h for 70 g L^-1 xylose NBS medium).
⁴⁾ The average productivity was calculated from the active production period (0 h to 78 h for 70 g L^-1 xylose fermentation; 0 h to 60 h for 100 g L^-1xylose fermentation, 0 h to 120 h for 70 g L^-1 xylose NBS fermentation).

ISSN: 1475-2859