Phosphatase Enzymes in Soils: Nature and Location of the Enzymes and Phosphorus Immobilization and Mineralization

Abstract

The nature and location of phosphatase enzymes produced by soil microorganisms under different copping and ecological conditions were evaluated by incubating the supernatant of a 1:10 soil-distilled water suspension for 40 weeks in microbial P-surplus and P- deficient conditions. At various time intervals, the cell-free, cell-bound, total dissolved P, dissolved inorganic P and turbidity of the cultures were determined. Results indicated that most of the phosphatase enzymes existed in a cell-bound rather than cell-free state irrespective of the P status of the medium during the first 8 weeks of incubation. Total phosphatase activity showed little tendency to decline with continued incubation. However, in all the systems the rate and extent of organic P mineralization varied but was not related to phosphatase activity. Phosphatase activity was also not related to the living biomass in these cultures