The synthetic xylulose-1 phosphate pathway increases production of glycolic acid from xylose-rich sugar mixtures

Table 7 Production of glycolic acid (GA) by different E. coli strains in medium containing glucose and xylose as carbon sources

Strain name	Additional modifications	Plasmids^a	Biomass	GA	GA yield on consumed sugar^b
Strain name	Additional modifications	Plasmids^a	Yield [g/g]	Final conc. [g/l]	G + X [g/g]	G [g/g]	X [g/g]
Pen1042		pGS	0.30 ± 0.01	1.58 ± 0.11	0.37 ± 0.04	0.30 ± 0.05	0.47 ± 0.04
Pen1044		pGS + pX1P	0.26 ± 0.03	2.41 ± 0.64	0.42 ± 0.01	0.36 ± 0.09	0.49 ± 0.04
Pen1099	galP ^proD	pGS + pX1P	0.24 ± 0.00	1.29 ± 0.00	0.33 ± 0.00	0.36 ± 0.02	0.35 ± 0.02
Pen905	∆xylB	pGS + pX1P	0.22 ± 0.02	1.98 ± 0.68	0.47 ± 0.12	0.37 ± 0.12	0.60 ± 0.11
Pen979	∆xylB galP ^proD	pGS + pX1P	0.23 ± 0.02	3.73 ± 0.16	0.63 ± 0.04	0.40 ± 0.01	0.75 ± 0.05

All strains carried the deletions ∆aceB ∆glcDEFGB ∆gcl ∆edd-eda ΔiclR ΔarcA Δicd. Additional modifications are indicated in the table. Initial glucose and xylose concentrations were 2.5 and 5 g/l, respectively. The mineral medium was supplemented with 2 g/l tryptone and 1 g/l yeast extract
G glucose, X xylose, G + X total sugar
^a pGS expresses glyoxylate reductase and isocitrate lyase, encoded by ghrA and aceA. pX1P carries (d)-xylulose-1 kinase, (d)-xylulose-1 aldolase and glycolaldehyde dehydrogenase, encoded by khkC, aldoB and aldA, respectively. pACT3 is the empty plasmid
^b Results are presented as mean ± STDV calculated from at least two replicate experiments

ISSN: 2731-3654