CYTOCHEMICAL LOCALIZATION OF ACID AND ALKALINE PHOSPHATASES IN ASPERGILLUS ORYZAE

Abstract

The intracellular localization of acid and alkaline phosphatases in Aspergillus oryzae A 1-5 was studied cytochemically with light and electron microscopy. Two different acid phosphatases were present, one (acid phosphatase I) having a pH optimum of 4.0 and the other (acid phosphatase II) of 5.5. They were shown to be localized at different sites in the fungal mycelium under this experimental condition; acid phosphatase I was demonstrated to be present at the surface of cell wall, whereas acid phosphatase II both at the surface of cell wall and at the cytoplasmic membrane. It was demonstrated cytochemically that excess amount of inorganic phosphate in growth medium promoted the formation of acid phosphatase I but repressed that of acid phosphatase II. Alkaline phosphatase was found to be localized in nucleoli and unknown electron-dense bodies in the cytoplasm. It was also seen at the surface of cell wall and at the cytoplasmic membrane.