Improved Production of Tryptophan in Genetically Engineered Escherichia coli with TktA and PpsA Overexpression

Table 2

Specific enzymatic activities of E. coli TRTH0709 harboring different constructs.

Strain/plasmid	Specific enzymatic activities (μmol/min/mg)
	Pps	Tkt
TRTH0709	0.070±0.002	0.091±0.002
TRTH0709/pMEL01	0.175±0.006	0.096±0.002
TRTH0709/pMEL02	0.073±0.004	0.324±0.005
TRTH0709/pMEL03	0.147±0.005	0.291±0.003

Enzymatic activities measured as μmol of enzymatic product liberated per min per mg of protein. All values represent the average of at least two separate determinations.