TABLE 1.
Bacterial strains and plasmids used in this work
| Bacterial strain or plasmid | Description | Source or reference(s) |
|---|---|---|
| Strains | ||
| Escherichia coli DH5α | Cloning host | Invitrogen |
| Escherichia coli XL1-Blue | Cloning host | Stratagene |
| Lactococcus lactis MG1363 | Expression host; plasmid cured | 41, 44 |
| Lactococcus lactis KP1 (NCK203) | Expression host; 2 native plasmids and 2 prophages | 45 |
| Lactococcus lactis subsp. lactis ATCC 11454 | Nisin producer and nisin-resistant L. lactis strain | ATCCa |
| Plasmids | ||
| pQE9 Cry5B | Source of cry5B gene for cloning | 46 |
| pSC-B | PCR cloning vector | Agilent Technologies |
| pTRK593 | pTRKH2-based cloning vector with P6 promoterb | 23 |
| pTRK1040 | Bt Cry protein Cry5B cloned into pTRK593 | This study |
| pTRK1041 | Bt Cry protein tCry5B cloned into pTRK593 | This study |
| pTRK1061 | pTRKH2-based expression vector with leaky system promoter and activator | This study |
| pTRK1062 | Bt Cry protein Cry5B cloned into pTRK1061 | This study |
| pTRK1063 | Bt Cry protein tCry5B cloned into pTRK1061 | This study |
| pMSP3535H3 | Nisin expression vector with nisin and erythromycin resistance genes | 34 |
| pTRK1068 | Bt Cry protein Cry5B cloned into pMSP3535H3 | This study |
| pTRK1069 | Bt Cry protein tCry5B cloned into pMSP3535H3 | This study |
a
American Type Culture Collection, Manassas, VA.
b
pTRKH2 is a 6.9-kb high-copy-number E. coli/Gram-positive shuttle vector encoding erythromycin resistance (32).