Table 3.

Utilization of d-glucose and l-arabinose and pyruvate kinase activity of aerobically grown wild-type strain, araR-deletion mutant, and recombinant strains expressing pyruvate kinase

Straina	Sugar concentration (g/L)b		Δ Arabinose–glucose (g/L)c	Pyruvate kinase activity (µmol/min/mg protein)d
	d-Glucose	l-Arabinose
Wild type	3.5 ± 1.5	9.2 ± 0.4	5.7 ± 1.2	0.54 ± 0.02
ΔaraR	2.1 ± 1.5	8.4 ± 0.3	6.2 ± 1.2	0.45 ± 0.06
pCHpyk	7.8 ± 0.8	9.5 ± 0.8	1.7 ± 1.2	1.17 ± 0.04
ΔaraR/pCHpyk	6.5 ± 1.3	7.1 ± 0.5	0.6 ± 0.8	1.61 ± 0.10

^a Recombinant strains were grown aerobically to late log phase in A medium containing 20 g/L of l-arabinose and 20 g/L of d-glucose and then inoculated to an initial OD₆₀₀ of 0.2 into mineral salt BT medium containing l-arabinose and d-glucose (15 g/L each) as carbon sources

^b After 23 h of cultivation, the culture supernatant was collected by centrifugation and subjected to sugar analysis. Data shown are average ± standard deviation calculated from the results of triplicate individual experiments

^c Values were determined based on the concentration of d-glucose and l-arabinose after 23 h of cultivation. Data are average ± standard deviation calculated from the results of triplicate individual experiments

^d Pyruvate kinase activity was determined using crude cell extract prepared from cells grown for 23 h in mineral salt BT medium containing l-arabinose and d-glucose (15 g/L each) as carbon sources. Data are average ± standard deviation calculated from the results of triplicate analyses