Research Article
Improved Production of Tryptophan in Genetically Engineered Escherichia coli with TktA and PpsA Overexpression
Table 1
Plasmids, strains, and primers used in the study.
| | Strain, plasmid, or primer | Characteristics | Source or reference |
| | Strains | | | | TRTH0709 | E. coli K12 ΔtrpRΔtna/pSV-709 (strain for expression and fermentation) | Laboratory stock | | TRTH1011 | TRTH0709/pMEL01 | Present study | | TRTH1012 | TRJH0709/pMEL02 | Present study | | TRTH1013 | TRJH0709/pMEL03 | Present study | | E. coli DH5α | deoR endA1 gyrA96 hsdR17 supE44 thi1 recA1 lacZM15 lpir (for routine transformation) | [14] |
| | Plasmid | | | | pSV-709 | pBR322 inserted with DCBA serA tetR | Laboratory stock | | pSTV28 | Plac cloning vector, pACYC184 origin, LacZ, Cmr | Takaha | | pMEL01 | pSTV28 inserted with ppsA | Present study | | pMEL02 | pSTV28 inserted with tktA | Present study | | pMEL03 | pSTV28 inserted with tktA and ppsA | Present study |
| | Primers | Nucleotide Sequence (sequences position at gene) | Gene amplification | | P1 | 5′-GATCCG AGCTCATGTCCTCACGTAAAGAGCTTGC-3′ (1–24) | tktA | | P2 | 5′-TATTGGGATCCTTACAGCAGTTCTTTTGCTTTCGC-3′ (1969–1992) | tktA | | P3 | 5′-GGTTTGGATCCATGTCCAACAATGGCTCGTC-3′ (1–20) | ppsA | | P4 | 5′-TGAAGGCATGCTTATTTCTTCAGTTCAGCCAGG-3′ (2358–2379) | ppsA |
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