CHARACTERIZATION OF EXTRACELLULAR ACID-PHOSPHATASES FROM THE YEAST ARXULA-ADENINIVORANS

The yeast Arxula adeninivorans secrets two multiple forms of acid phosphatase into the culture medium if grown under phosphate limitation. The phosphatases were separated one from each other by chromatography on cellulose phosphate. Investigating the enzymes of two strains from A. adeninivorans we could show that their phosphatases have similar properties. The optimum temperature for the enzyme activity was 50 to 55-degrees-C and the highest activity was obtained in a pH range between 5.2 and 5.5. The K(m) value for p-nitrophenyl-phosphate was determined for all of the enzymes to be 3.5 mM. The molecular weight of enzyme I was found to be 320,000 and that for enzyme II 250,000; after deglycosylation with endoglycosidase H it was 75,000 and 46,000, respectively.