Figure 2

Antifungal activity of S. cyanogenus ΔlanI7 pGM4181⁺ as a function of cultivation time (a, b) and origin of adpA gene (c). For D. hansenii growth inhibition assay (a) the extracts were prepared from YMPG-grown ΔlanI7 pGM4181⁺ (1) and ΔlanI7 (2) at timepoints shown in the figure. The initial strain ΔlanI7 (2) showed no activity at all investigated time points. LC–MS quantification of the Lcm mass peak in the same extracts (b) was in agreement with the results of the bioassay. Data represent mean values of three independent experiments ± 2SD. (c) D. hansenii growth inhibition assay showing that adpA genes (and corresponding DNA-binding domains, DBD), other than XNR_4181, were able to activate Lcm production in S. cyanogenus ΔlanI7: (4,5)—ΔlanI7 pGMSCO⁺ and pGMSCOd⁺, overexpressing S. coelicolor adpA and its DBD, respectively; (6,7)—ΔlanI7 pGMSCLA⁺ and pGMSCLAd⁺, S. clavuligerus adpA and its DBD, respectively; (8,9)—ΔlanI7 pGM4181⁺ and pGM4181d⁺, S. albus adpA and its DBD, respectively; (10,11)—ΔlanI7 pOOB95d⁺ and pGMSGHd⁺, S. ghanaensis adpA and its DBD, respectively. Initial strain (1) as well as strains carrying native adpA from S. cyanogenus (ΔlanI7 pGMSCY⁺) and its DNA-binding domain (ΔlanI7 pGMSCYd⁺) do not inhibit growth of D. hansenii. Agar plugs were cut from the lawns grown on YMPG agar for 120 h.