FIG. 5.

Phase-contrast micrographs of the wild-type strain and S. griseus mutants during sporulation induced by phosphate starvation in submerged culture. NRRL B-2682 (A to C), wild-type strain; SKK2663 (D to F), ssfR null mutant; SKK2664 (G to I), ssgA null mutant. Cells were starved for 0 (A, D, and G); 6 (B, E, and H), and 24 h (C, F, and I). Arrows in panels A and G, vegetative hyphae; arrows in panels B, D, E, and H, sporogenic hyphae; arrows in panels C and F, spores; arrow in panel I, deformed sporogenic hypha. Bar, 5 μm.