Table 1

Strains and plasmids used in this study

Strain or plasmidDescriptionSource or reference
Strains
    Microalgae
        Chorella sorokiniana strain RPIsolated from freshwater ponds in Buenos Aires, Argentina, in 2009Laboratory collection
        Scenedesmus obliquus strain C1SIsolated from freshwater ponds in Buenos Aires, Argentina, in 2009Laboratory collection
        Pseukirchneriella sp. strain C1DIsolated from freshwater ponds in Buenos Aires, Argentina, in 2009Laboratory collection
    Azotobacter vinelandii
        DJWild typeD. Dean
        AV2ΔnifA::SpThis study
        AV3ΔnifLThis study
        UW211nifHp-lacZ14
        UW218ΔnifA::Sp nifHp-lacZ14
        UW226ΔnifL nifHp-lacZThis study
    Escherichia coli DH5αF′ endA1 glnV44 thi-1 recA1 relA1 gyrA96 deoR nupG ϕ80dlacZΔM15 Δ(lacZYA-argF)U169 hsdR17(rK mK+) λ34
Plasmids
    pUK21Cloning vector37
    pRHB138Source of A. vinelandii ΔnifA::Sp allele14
    pRHB142Partial construction of A. vinelandii ΔnifL alleleThis study
    pRHB143Source of A. vinelandii ΔnifL alleleThis study