Table S1.
Strains and plasmids used in this study
| Strain/plasmid | Relevant characteristics | Source |
| P. stutzeri strains | ||
| A1501 | WT, Chinese Culture Collection: CGMCC 0351 | (54) |
| ATCC17588 | WT, Chinese Culture Collection: CGMCC 1.1803 | |
| A1550 (ΔrpoN) | rpoN-Cm deletion mutant, Cmr | (24) |
| A1565 (ΔntrC) | ntrC-Cm deletion mutant, Cmr | (32) |
| A1506 (ΔnifA) | nifA-Km deletion mutant, Kmr | (24) |
| A1507 (ΔrpoS) | rpoS-deletion mutant; the rpoS gene was knocked out by homologous suicide plasmid integration using pK18mobsacB as the vector | Lab collection |
| A1521 (Δhfq) | hfq nonpolar insertion mutant; the hfq gene was inactivated by homologous suicide plasmid integration using pK18mob as the vector, Kmr | This study |
| A1522 | hfq nonpolar insertion mutant containing pLAhfq-A1501, Kmr and Tcr | This study |
| A1514 | A1501 containing pLAnfiS-A1501, Tcr | This study |
| A1701 | nfiS-Spc deletion mutant strain, Spcr | This study |
| A1706 | A1701 containing pLAnfiS-A1501, Spcr and Tcr | This study |
| A1707 | A1701 containing pLAnfiS-del9, Spcr and Tcr | This study |
| A1708 | A1701 containing pLAnfiS-ATCC, Spcr and Tcr | This study |
| A1709 | A1701 containing pLAnfiS-mut5, Spcr and Tcr | This study |
| Plasmids | ||
| pK18mob | Mobilizable plasmid containing an Escherichia coli origin of replication, Kmr | (58) |
| pK18mobsacB | Allelic exchange vector, Kmr | (58) |
| pLAFR3 | Mobilizable vector, Tcr | (60) |
| pRK2013 | Helper plasmid for conjugation into P. stutzeri A1501, Kmr | (59) |
| pKatAAD2 | Source of spectinomycin resistance cassette, Spcr | Lab collection |
| pMD18-T | 2.96-kb cloning vector, Ampr | Takara |
| pK18/delS | pK18mobsacB derivative carrying a BamHI/HindIII fragment for homologous recombination, Spcr, Kmr | This study |
| pLAnfiS-A1501 | pLAFR3 derivative carrying the WT nfiS gene under the control of its endogenous promoter, Tcr | This study |
| pLAnfiS-mut5 | pLAFR3 derivative carrying a mutated nfiS gene with a substitution of five nucleotides within the pairing site region, Tcr | This study |
| pLAnfiS-del9 | pLAFR3 derivative carrying a mutated nfiS gene with a complete deletion of the 9-nt sequence downstream of the pairing site, Tcr | This study |
| pLAnfiS-ATCC | pLAFR3 derivative carrying the WT nfiS homolog from P. stutzeri ATCC17588 under the control of its endogenous promoter, Tcr | This study |
| pLAhfq-A1501 | pLAFR3 derivative carrying the WT hfq gene under the control of its endogenous promoter, Tcr | This study |