FIG. 4.
Growth of P. stutzeri htx, ptx, and phn deletion mutants on minimal media with various P sources after 4 days of growth. (A) Fresh cultures were streaked from MOPS minimal solid agar containing 0.1 mM Pi onto MOPS minimal agar containing the indicated P sources (phosphite [Pt], hypophosphite [Hpt], inorganic phosphate [Pi], aminoethylphosphonate [Aepn], and methylphosphonate [Mpn]) at 0.5 mM. The schematic on the plate lacking phosphorus (No P) represents the order in which the deletion mutants were streaked: 1, Δhtx Δphn mutant (WM3616); 2, Δphn mutant (WM3614); 3, Δhtx mutant (WM1926); 4, wild type (WM567); 5, Δphn Δptx mutant (WM3748); 6, Δhtx Δptx mutant (WM3747); 7, Δptx mutant (WM3746); and 8, Δptx-htx Δphn mutant (WM3617) (B and C). Representative Δhtx Δptx and Δptx mutant colonies showing enhanced growth that were grown on phosphite (B) and hypophosphite (C) are indicated by white arrows.