Enzymatic activity as a diagnostic indicator of soil pollution in Solovetsky settlement

Abstract

This article presents the catalase activity as a diagnostic indicator of soil contamination by oil products and heavy metals by the example of the Solovetsky soil. 44 soil samples were taken during two summer expeditions launched by M. Lomonosov Northern (Arctic) Federal University in 2016 and 2017. The average content of organic matter (in terms of carbon) is 10%. The highest amount of carbon is found in peated, upper horizons (litter), ranging from 20 to 48%, and imbedded sandy layers - from 0.1% to 5%. The analyzed soils are slightly acidic and therefore are favorable for enzymes activity. Some of the soils in Solovetsky settlement were found to be contaminated with heavy metals and petroleum products, the latter affecting the catalase activity in oppositely directed ways. High levels of petroleum products lead to a marked decrease in the enzyme activity. The high content of heavy metals is likely to cause an increase in enzymatic activity, triggered by the protective mechanisms in microorganisms in response to the increase in heavy metals content. This leads to enhanced formation of reactive oxygen compounds, for the disposal of which catalase is responsible. Our study has confirmed the potential of catalase activity to be used as an indicator of the state of soils in Solovetsky settlement, known to be exposed to various types of pollution.