Production of an exocellular acid phosphatase by the yeast Hansenula holstii NCYC 560

1. The yeast Hansenula holstii NCYC 560 produced invertase and an inducible acid phosphatase located betweent the cytoplasmic membrane and the yeast cell wall. 2. These enzymes were also found in the culture medium outside the cell boundaries. 3. The amount of cell wall mannan in cells grown in phosphate-limited medium decreased in comparison with that of cells grown in phospahte-rich medium. 4. It is proposed that the mannan in this yeast is a loose and highly permeable structure, allowing external enzymes to leave the cell boundaries.