TABLE 1.
Bacterial strains and cosmids used in this study
| Strain or plasmid | Characteristicsa | Source or reference |
|---|---|---|
| Strains | ||
| Bradyrhizobium japonicum | ||
| USDA110 | Wild type; nosZ+ | 23 |
| T7 | Field isolate in Tokachi, Hokkaido, Japan; nosZ natural mutant | 32, 43 |
| USDA110ΔnosZ | USDA110 nosZ::del/ins Ω cassette; Smr Spr | This study |
| Escherichia coli | ||
| DH5α | recA; cloning strain | Toyobo Inc. |
| JM109 | recA; cloning strain | Toyobo Inc. |
| HB101 | recA hsdR hsdM pro Smr | 5 |
| S17-1 | hsdR RP4-2(kan::Tn7)(tet::Mu); Smr Spr | 47 |
| Plasmids | ||
| pRK2013 | ColE1 replicon carrying RK2 transfer genes; Kmr | 13 |
| pTZ18R | Cloning vector; pMB1ori; Apr | 46 |
| pTZ18RnosZ | pTZ18R carrying 4.0-kb nosZ fragment; Apr | This study |
| pTZ18rRΔSacI-nosZ | SacI-deleted pTZ18R carrying 4.0-kb nosZ fragment; Apr | This study |
| pHP45Ω | Plasmid carrying 2.1-kb Ω cassette; Spr Smr Apr | 40 |
| pK18mob | Cloning vector; pMB1ori oriT; Kmr | 46 |
| pK18mob-nosZ::Ω | pK18mob carrying 4.0-kb nosZ fragment; Kmr Smr Spr | This study |
| Cosmids | ||
| pKS800 | Derivative of broad-host-range cosmid pLAFR1; IncP Tcr | 17, 23 |
| brc02856 | pKS800 carrying nos gene clusterb; Tcr | 23 |
| brc01733 | pKS800 carrying nos gene clusterb; Tcr | 23 |
a
Apr, ampicillin resistant; Tcr, tetracycline resistant; Kmr, kanamycin resistant; Smr, streptomycin resistant; Spr, spectinomycin resistant.
b
See Fig. 1.