TABLE 1.
Bacterial strains and plasmids used in this studya
| Strains and plasmids | Relevant characteristic(s) | Source or reference |
|---|---|---|
| Strains | ||
| S. thermophilus | ||
| ATCC 19258 | Type strain of S. thermophilus | ATCC |
| TM1-1 | Spontaneous thyA mutant of ATCC 19258 | This study |
| OLL1131 | Industrial strain for yogurt production | Meiji Dairies Corporation |
| OILL3074 | Industrial strain for yogurt production | Meiji Dairies Corporation |
| L. delbrueckii subsp. bulgaricus M-878 | Industrial strain for yogurt production | Meiji Dairies Corporation |
| E. coli TGthy2 | Spontaneous thyA mutant of E. coli TG1 | This study |
| Plasmids | ||
| pBUL1 | Endogenous plasmid (7.9 kb) of L. delbrueckii subsp. bulgaricus M-878 | 20 |
| pBSt1 | 8.9 kb; Thy+; pBUL1 + thyASt | This study |
| pBLb1 | 8.9 kb; Thy+; pBUL1 + thyALb | This study |
| pX3 | 9.1 kb; Emr; pBUL1 + ermA | 20 |
| pXTLb | 10.1 kb; Emr Thy+; pX3 + thyALb | This study |
| pX4041 | 10.1 kb; Emr Thy+; pX3 + thyASt | This study |
| pSY1 | Endogenous plasmid (2.9 kb) of L. lactis M-128C (Meiji Dairies Corporation) | 21 |
| pSLb1 | 4.0 kb; Thy+; pSY1 + thyALb | This study |
| pSLbA1 | 7.0 kb; Thy+ Amy+; pSLb1 + amyA | This study |
| pSYE2 | 3.9 kb; Emr; pSY1 + ermA | 21 |
| pSYTLb | 5.2 kb; Emr Thy+; pSYE2 + thyALb | This study |
| pSG+E2 | 3.9 kb; ts replication, Emr; ori of pSYE2 replaced with ts ori of pG+host5 (4) | Unpublished results |
| pSintA1 | 8.0 kb; Thy+ Amy+; ts replication, pSG+E2 + thyALb + amyA + two lacZ fragments (ermA deleted) | This study |
a
Thy, thymidine; Em, erythromycin.