FIG 6.

(a) Bound GFP-chitinase levels and chitin levels of wild-type strain BY4742 and BY4742 Δygp1 and BY4742 Δtus1 mutant strains. GFP-chitinase levels bound to yeast strains and amount of cell wall chitin were quantified using a BD FACSAria flow cytometer. Cells were grown in YPD, as described by de Groot et al. (43), and equal amounts of cells based on OD measurement at 600 nm were washed and resuspended in PBS buffer before adding GFP-tagged chitinase or before staining with calcofluor white for chitin quantification. Fluorescence intensity is expressed in arbitrary units (a.u.). (b) Fold change of the deletion mutant strains relative to the wild-type strain BY4742. A correlation of 0.98 was obtained between the amount of yeast cell wall chitin and the amount of GFP-chitinase bound to the cell wall.