四氯化碳污染对土壤酶活性的影响

Effects of Carbon Tetrachloride Contamination on Enzyme Activities in Soil

采用模拟实验方法，研究了四氯化碳（CCl4）污染对土壤中蛋白酶、脲酶、过氧化氢酶等主要酶活性的影响．蛋白酶活性、脲酶活性、过氧化氢酶活性分别采用铜盐比色法、纳氏试剂分光光度计法和高锰酸钾滴定测试．结果显示，四氯化碳浓度越高，对蛋白酶和脲酶活性的抑制越强，呈现出先抑制后恢复的过程．训（CCl4）〈1．6×10^-6时对土壤蛋白酶无明显的抑制作用，训（CCl4）〉3．2×10^-6时对土壤蛋白酶和脲酶均有明显的抑制；抑制强度第1天为7．90％～38．86％，影响时期长约5d；对脲酶的抑制第1天为51％～72%，影响期约1d；四氯化碳对土壤过氧化氢酶的活性没有显著性抑制，反而有微小的激活作用，四氯化碳污染（w（CCl4）：1．6×10^-6～16．0×10^-6）的土壤微生物表现出较强的抵抗过氧化的防御能力．显然土壤脲酶对四氯化碳反应最敏感．酶对四氯化碳污染的不同反应将影响污染区土壤的质量及性能．

Using the method of stimulation experiment, the effects of carbon tetrachloride（CT） concentrations on the three main enzyme activities in the soil： protease, urease, catalase were studied. Copper salts assay, Nessler＇s reagent spectrophotometer method and potassium permanganate titrimetric method were taken to detect the activities of protease, urease and catalase. The results show that increasing initial concentration resulted in higher inhibition to protease activity and urease activity. The process was inhibited firstly and then recovered. The protease activity was more obviously inhibited by CT of 3.2× 10^-6 but wasn＇t inhibited by CT of 1.6×10^-6 , this inhibition was 7.90%-38.86% first day and the inhibition term was about 5 days; Above 1.6× 10^-6 of CT had highly significant inhibition （51%-72%） to urease activity first day, the inhibition term was about 1 day. CT of 1.6× 10^-6 -16.0× 10^-6 hasn＇t obvious inhibition to catalase activity and even had a little activation. It showed that catalase had great capacity from peroxidation. Soil urease was the most sensitive to CT. The different effects of different enzyme could affect the properties and function of the CT contamination soil.