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

Table 6 Production of glycolic acid by different E. coli strains in medium containing xylose as carbon source

Strain name	Additional deletions	Plasmids^a	Biomass	Glycolic acid		Acetate
Strain name	Additional deletions	Plasmids^a	Yield [g/g]	Final conc. [g/l]	Yield [g/g]	Final conc. [g/l]	Yield [g/g]
Pen1100		pACT3	0.10 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	4.20 ± 0.01	0.57 ± 0.00
Pen1042		pGS	0.16 ± 0.01	2.11 ± 0.49	0.29 ± 0.05	0.16 ± 0.23	0.02 ± 0.03
Pen1044		pGS + pX1P	0.13 ± 0.03	1.57 ± 0.24	0.24 ± 0.02	0.55 ± 0.11	0.08 ± 0.02
Pen1048	ΔxylB	pX1P	0.09 ± 0.01	2.70 ± 0.16	0.45 ± 0.01	1.97 ± 0.31	0.33 ± 0.04
Pen905	ΔxylB	pGS + pX1P	0.08 ± 0.01	2.24 ± 0.46	0.43 ± 0.05	1.34 ± 0.01	0.26 ± 0.02

All strains carried the deletions ∆aceB ∆glcDEFGB ∆gcl ∆edd-eda ΔiclR ΔarcA Δicd. Additional deletions are indicated in the table. Initial xylose concentration was 10 g/l. The mineral medium was supplemented with 2 g/l tryptone and 1 g/l yeast extract
^apGS 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. Results are presented as mean ± STDV calculated from at least two replicate experiments

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