Sensitivity of the mp65Δ mutant to different cell wall-perturbing and degrading agents. (A) Microdilution sensitivity assay. The wild type (wt: black column), mp65Δ mutant (hom: grey column) and revertant (rev: white column) strains were quantitatively tested for sensitivity to different cell wall-perturbing agents using the microdilution method, as specified in the Methods section. Each column represents the mean of 3 experiments, with the bars representing standard deviations. (B) Solid medium spotting assay. The wild type (wt), mp65Δ mutant (hom) and revertant (rev) strains were tested by spotting decreasing cell counts on YEPD plates with or without cell wall-perturbing agents, as specified in the Methods section. Column 1 corresponds to the cell suspension and columns 2-6 correspond to 1:5 serial dilutions. (C) Sensitivity to Zymolyase. The wild type (wt), mp65Δ mutant (hom) and revertant (rev) strains were incubated in 10 mM Tris/HCl, pH 7.5, containing 25 μg/ml of Zymolyase 100T; the optical density decrease was monitored over a 140 min period.