Engineering Escherichia coli for succinate production from hemicellulose via consolidated bioprocessing

Table 2 The physiology and enzymatic properties of Z1EX0 series strains

Strain	Xylanases expressed	Max OD₆₀₀	Protein secretion (g/l)		Endoxylanase activity		Xylosidase activity
			8 h(16 h)^a	24 h	(U/L)	(U/mg)	(U/L)	(mU/mg)
Bl21(DE3)	-	6.50 ± 0.17	0.03 ± 0	0.03 ± 0	n.d.^b	n.d.^b	n.d.^b	n.d.^b
Z1000	-	6.19 ± 0.08	0.04 ± 0	0.03 ± 0	n.d.^b	n.d.^b	n.d.^b	n.d.^b
Z1140	E₁, X₄	3.45 ± 0.04	0.30 ± 0.02	0.69 ± 0	398 ± 13	1.31 ± 0.07	24 ± 1.0	80 ± 4
Z1150	E₁, X₅	4.08 ± 0.12	0.19 ± 0.01	0.31 ± 0.03	65 ± 2	0.34 ± 0.01	14.3 ± 0.6	75 ± 4
Z1160	E₁, X₆	4.55 ± 0.05	0.10 ± 0.01	0.21 ± 0.02	75 ± 0	0.75 ± 0.04	6.1 ± 0.3	61 ± 5
Z1170	E₁, X₇	2.02 ± 0.05	0.60 ± 0.04	0.95 ± 0.03	420 ± 19	0.70 ± 0.04	46.3 ± 0.5	77 ± 3
Z1240	E₂, X₄	5.12 ± 0.12	0.10 ± 0.01	0.17 ± 0.01	274 ± 10	2.71 ± 0.19	8.0 ± 0.3	77 ± 6
Z1250	E₂, X₅	5.69 ± 0.29	0.11 ± 0.02	0.12 ± 0.03	50 ± 4	0.47 ± 0.03	6.8 ± 0.2	63 ± 7
Z1260	E₂, X₆	4.83 ± 0.05	0.07 ± 0	0.10 ± 0	90 ± 5	1.36 ± 0.04	4.5 ± 0.2	64 ± 1
Z1270	E₂, X₇	4.07 ± 0.05	0.34 ± 0.01	0.43 ± 0.02	423 ± 14	1.25 ± 0.04	29.3 ± 1.2	86 ± 3
Z1340	E₃, X₄	5.10 ± 0.03	0.08 ± 0.01	0.21 ± 0.01	1098 ± 28	13.22 ± 1.05	7.3 ± 0.2	88 ± 7
Z1350	E₃, X₅	3.97 ± 0.09	0.22 ± 0	0.51 ± 0.04	1512 ± 2	6.88 ± 0	10.9 ± 0.5	49 ± 1
Z1360	E₃, X₆	4.93 ± 0.10	0.08 ± 0	0.25 ± 0	996 ± 1	13.14 ± 0.01	5.9 ± 0.2	77 ± 1
Z1370	E₃, X₇	5.04 ± 0.05	0.18 ± 0.01	0.25 ± 0.01	2151 ± 14	12.14 ± 0.34	16.3 ± 0.2	92 ± 3

^a Except maximum OD₆₀₀, the sampling time was at the late-exponential phase, which was at about 8 h after induction for strains Z13X0 and the two controls, and 16 h for the other strains.
^b n.d.: not detectable.

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