Research Paper Volume 11, Issue 19 pp 8418—8432

Figure 1. Deletion of SCH9 decreased H₂S production in different yeast strains. (A) WT and Δsch9 cells in the TB50a background were transformed with pRS316-SCH9 or empty vector and inoculated into 1L of SDC medium at initial OD_600nm=0.005. H₂S production was monitored using lead acetate strips at indicated times (Upper 3 panels) after inoculation. The level of Sch9 protein and actin loading control were determined by Western blotting as shown in the lower 2 panels. (B) Millimeters of darkening of the lead acetate strips inserted into the headspace of the culture flask shown in panel A normalized by OD_600nm. (C) Methylene blue assays of H₂S produced by WT and Δsch9 cells in BY4741 or BY4742 background. Note that there is spontaneous oxidation of methylene blue when H₂S is absent which gave negative readings for methylene reduction (red and blue dash lines). (D) Intracellular H₂S production in WT and Δsch9 cells in BY4741 or BY4742 background monitored by H₂S fluorescent with probe WSP-1. (* p<0.05; ** p<0.01; *** p<0.005). (E) H₂S production by WT and Δsch9 cells in BY4742 background assayed by using lead acetate strips which were replaced every 24 hours under caloric restriction conditions (CR, medium containing 0.5% glucose) or no restriction (NR, medium containing 2% glucose).