Enzymes as useful tools for environmental purposes

•Enzymes play a main role in biological remediation.•Enzyme activity in pollutant transformation can be improved by low-molecular weight additives.•Immobilized enzymes are suitable for continuous processes for long-term and operational stability.•Enzymes could act as biosensors in environmental pollution monitoring.•Enzymes could act as bioindicators of water or soil quality and health. In the environment enzymes may play important and different roles at least in three cases: as main agents (as isolated, cell-bound or immobilized enzymes) in charge of either the transformation and/or degradation of compounds polluting the environment and the restoration of the polluted environment; as reliable and sensitive tools to detect and measure the amount and concentration of pollutants before, during and after the restoration process; as reliable, easy and sensitive indicators of quality and health status of the environment subjected to the restoration process. To our knowledge papers or reviews integrating findings on these three functions of enzymes are missing in literature. Therefore the main scope of the present paper is to briefly encompass general and specific concepts about roles of enzymes as decontaminating agents, pollutant assaying agents and indicators of environment safety. Examples chosen among those published very recently, supporting and confirming peculiarities, features, and performance of enzymatic agents will be illustrated.