Thermodynamic indices of active invertase from the buried soil horizons of Late Pleistocene age in northern Yakutia

Abstract

New data on the enzymatic activity of the tundra peaty gleyey soil and permafrost sediments of Late Pleistocene age (11–25 thousand years) are analyzed. It is shown that invertase, protease, phosphatase, catalase, and peroxidase are well conserved in yedoma and in buried soil horizons; urease is conserved to a smaller extent. On the basis of the investigation of thermodynamic characteristics of active invertase, such as temperature coefficient and activation energy, it was established that this enzyme is present in soil in the free and bound forms (immobilized on the surface of organomineral colloids). The degree of immobilization of active invertase in the buried soil horizons is high, which plays an important part in the long-term conservation of its molecules at subzero temperatures.