FIG. 4.

Effect of 500 mM sucrose with and without preincubation. Conditions were as described in the text, except that the activity in 500 mM sucrose was determined with (dashed line) and without (solid line) 2 h of preincubation of cells in sucrose before the addition of sulfur to start the reaction. O₂ consumption tracings in the absence of 500 mM sucrose (in water and in 50 mM K₂SO₄) are also shown for the oxidation of sulfur at pH 2.3.