FIG. 1.

SDS-PAGE analysis of ΔSterne-1(pPA102)CR4 culture supernatants from complete, reduced-yeast-extract, and reduced-tryptone media. Lanes: 1, complete medium with 33 g of tryptone/liter and 20 g of yeast extract/liter; 2, complete reduced yeast extract medium with 33 g of tryptone/liter and 5 g of yeast extract/liter; 3, complete reduced tryptone medium with 8.25 g of tryptone/liter and 20 g of yeast extract/liter. A 1-ml sample was removed from each culture at late log to early stationary phase. The samples were sterile filtered, buffer exchanged, and concentrated to equivalent volumes. Equivalent volumes were loaded for SDS-PAGE analysis.