Differential stabilities of soil enzymes. Assay and properties of phosphatase and arylsulphatase.
Methods have been refined for the assay of phosphatase and arylsulphatase activities in soil, based on the chromogenic p-nitrophenyl ester substrates. Basic assay conditions have been defined, and pH optima and kinetic parameters have been determined. The enzymes follow Michaelis-Menten kinetics; this conclusion is based on three methods of analysis of data determined over a wide range of substrate concentrations. The enzyme activities are very stable to storage of wet soil for up to 4 weeks at soil temperatures and above. For example, phosphatase had a half-life of approximately 2 weeks at 50 degrees C; arylsulphatase was rather less stable. Both enzymes retained 80% of activity after incubation with pronase for 1 week at 25 degrees C. On the basis of this work and studies on other soil enzymes, it is concluded that remarkable stability is a general feature of soil enzymes.
D001192:Arylsulfatases / Q000378:metabolism*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D013429:Sulfatases / Q000378:metabolism*; D013696:Temperature
D012987:Soil; D010744:Phosphoric Monoester Hydrolases; D013429:Sulfatases; D001192:Arylsulfatases