Table 2 Bacterial strains and plasmids used in this study
Strain | Characteristics | Source |
|---|---|---|
E. coli DH5α | Cloning host for maintaining recombinant plasmids | Lab collection |
L. lactis NZ9000 | Derivative of MG1363; pepN::nisRK | [37], Lab collection |
L. lactis NZB | Derivative of NZ9000; P nisZ ::lacZ::terminator | This study |
Plasmids | ||
pUC18 | Cloning vector; Ap r | Lab collection |
pUC-H | Derivative of pUC18; containing His fragment from L. lactis | This study |
pCrePA2 | An improved version of the pCrePA [29] plasmid containing Ts replicon; Ap r, Em r | Kindly gifted by Stephen H. Leppla |
pJW | L. lactis integration vector; derivative of pUC-H; containing Ts replicon from pCrePA2; Ap r, Em r | This study |
pMG36e | Wide-host-range vector; Em r | [15], Lab collection |
pQE31-LacZ | Derivative of the expression vector pQE31; containing lacZ from Lactobacillus acidophilus; Ap r | [34], Lab collection |
pMG-PZL | derivative of pMG36e; containing P nisZ ::lacZ; template of P nisZ ::lacZ::terminator; Em r | This study |
pJW-PZLT | L. lactis integration vector; derivative of pJW; containing P nisZ ::lacZ::terminator; Ap r, Em r | This study |