Effect of toluene on arylsulfatase activity in soil
甲苯对土壤芳基硫酸酯酶活性的影响

Toluene is the pre-treatment reagent for assaying soil enzymes, and is one of the intermediates of many organic pollutants that are degraded in the environment. The research of toluene affecting soil enzyme has great significance in soil enzymology and environmental science. Therefore, by simulation methods,the variation of pure and soil arylsulfatase activity affected by toluene with different concentrations and time were studied systematically. The results showed that toluene inhibited the pure arylsulfatase significantly, with the largest decrement in activity as 45.5%. The sterilized soil had great ability to absorb pure enzyme in solution. Very trace toluene could increase the soil enzyme activity greatly, with the increasing variation of 109%~298% as that without toluene treatment. With further increasing toluene concentration, soil enzyme activity kept increasing but with a slower rate. Langmuir equation could fit the variation of soil enzyme activity well, and the maximum activity can be thus obtained which was significantly correlated with soil properties. It was revealed that toluene affected soil enzyme activity mostly by killing the soil microorganism. In tested soil sample, the extracellular and intracellular soil arylsulfatase activity was 54.4% and 45.6% on average, respectively. The results provided scientific support for improving the quality of soil enzyme assay.