改良茚三酮比色法测定土壤蛋白酶活性的研究

通过引入Ca2 为蛋白酶激活剂、以Pb(CH3 COO) 2 和Na2 C2 O4—CH3 COOH混合试剂作为除杂剂、将抗坏血酸与KIO3 结合起来以提高茚三酮比色法测定氨基酸的灵敏度和稳定性,并使培养和测定两个过程的pH缓冲体系有机结合起来,从而全面改进了土壤蛋白酶活性的测定方法。用该方法测定了潮土、黄棕壤和红壤的蛋白酶活性,并与常用的Folin比色法进行了试验比较,证明该方法适合于测定中性、碱性土壤的蛋白酶活性并优于Folin比色法

DETERMINATION OF SOIL PROTEASE ACTIVITY WITH MODIFIEDNINHYDRIN COLORIMETRY

Much improvement has been made to the method of ninhydrin colorimetry for determination of soil protease activity. The major improvement were: introducing Ca 2 as protease activator, and lead acetate and sodium oxalate acetic acid as precipitator, and using antihemorrhagic vitamin coupled with potassium iodate to improve sensitivity and stability of the ninhydrin colorimetry in quantifying the amino acid. The buffer systems of incubation and measurement were also adjusted for better performance of the ninhydrin colorimetry. Comparison between the modified method and the widely used method of Folinphenol colorimetry was made in determination of protease activity using three different soils (Fluvo aquic soil, yellow brown earth and red soil) and found that the modified method is much better than the Folinphenol colorimetry for neutral and alkaline soils.