Soil protease is involved in the transformation of amino acids, proteins and other organic compounds
containing protein nitrogen in soil. Those hydrolytic product is one of the nitrogen sources of higher plants.
Soil neutral protease catalyzes the hydrolysis of protein in neutral environment, which is related to soil
organic matter content, nitrogen and other soil properties. Under neutral conditions, soil neutral protease
could hydrolyze casein to produce tyrosine. In alkaline conditions, tyrosine reduced phosphomolybdic acid
compound to form tungsten blue with absorbance peak in 680 nm.
Reagents and Equipment Required but Not Provided:
Spectrophotometer, water bath, transferpettor, 1 mL glass cuvette, methylbenzene, distilled water, 50
mesh sieve(or smaller).
