Acid Phosphatase And Its Interaction With Heavy Metals, Hg(Ⅱ),Cu(Ⅱ),Zn(Ⅱ)

In text the main effects of pollutions including acid rain, Cu 2+, atrazine and their combined products on the activities of urease, intertase and acid phosphatase are studied by means of orthogonal test. The results showed that H+ and Cu2+ have significant influence on the activities of enzymes and the ability of their inhibiting three hydrolases activities follow the order: H+>Cu2+. A13+ and atrazine have not significant influence on three hydrolases. Furthermore, interaction analyses reveal that CuxH affect on the activity of acid phosphatase significantly, Cuxatrazine exhibit the synergism on the activity of enzyme, but atrazinexll have non-interaction within the investigated concentration range. Among three enzymes, acid phosphalase is the most sensitive one to the contaminations.Soil acid phosphatase is studied detailedly on account of its sensitivity to external contaminations.The relations of soil physics and chemistry properties and activity of acid phosphatase are also researched by means of path analysis. The results show that soil organic matter, total nitrogen and total phosphorus are major factors to effects on the activity of soil acid phosphatase. The direct and indirect effects of them on the activity of soil acid phosphatase are all significant. One of the reasons is that organic matter is main carrier of soil enzyme. On the other hand the sources of carbon, nitrogen and phosphorus which exist extensively in fecund soil can be used as substrates of enzyme. Soil clay and pH directly affect on the activity of enzyme. While the CEC has weak influence on them. It is obvious that the activities of soil acid phosphatase in different types and properties soils have remarkable differences.The kinetic parameters of enzymatic reactions in twelve soil samples are calculated, including michaclis constant^,), maximal speed(Fmax), equilibrium constant(/Q and activation energy().Further, the kinetic parameters of enzymatic reactions correlate with soil properties The results indicate that the values of Km have biggish difference although they are in the same order of magnitude. The differences are probably caused by different soil environment and adsorbed degree of substrate. The value of Km has perfect correlativity with soil organic matter, total nitrogen except in 20 癈. And when the temperature is 10"C, 20 癈 A'n, has significant correlativity with total phosphorus. The value of Vmax of the same soil increases with the increasing temperature and it's badly relative to soil physics and chemistryinproperties. The values of K have biggish differences in twelve soil samples and A.' is bigger in fecund soil. The values of K present irregularity when different temperatures affect on the soil acid phosphatase. The values of Ea in paddy soils are bigger than wetland soils, and it's smaller in lateritic loam and saline alkali soil. The correlation analysis shows that the value of Ea of enzymatic reaction has perfect correlativity with soil organic matter and total nitrogen, but not other soil properties.By the aid of the above, the properties of soil acid phophatase are thoroughly known and according as the properties the soil samples are selected. Hg2+, Cu2+ and Zn2+ are added in different soils. The experimental results show that Hg2+>Cu24>Zn2+ inhibit the enzyme activity distinctly. Three heavy metals significantly influence the activity and kinetic parameter of acid phosphatase. And the levels of addition of heavy metals have good correlativity with these parameters. So the activity and kinetic parameter (Fmax, fmax/^m) of soil acid phosphatase can be used as auxiliary index of soil pollution. The values of Fmax of three soils decrease with the increasing concentrations of Hg2+, Cu2+ and Zn2+, while Km has irregular changes. The results of kinetic studies suggest that Hg2+, Cu2+ and Zn2+ are compound of non- and uncompetitive inhibitors of acid phosphatase.A majority of enzymes exist in soil in form of immobile enzymes. The acid phosphatase from wheat germ is studied as effector in or...