Environmental security is one of the major concerns for the safety of living organisms from a
number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as
well as scientific and social concerns have been discussed and adopted to control and regulate
the threats of environmental pollution, but it still remains a worldwide challenge. Therefore,
there is a need for developing certain sensitive, rapid, and selective techniques that can detect
and screen the pollutants for effective bioremediation processes. In this perspective, isolated
enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can
be used as a source for detection, quantification, and degradation or transformation of
pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal
for the detection and measurement of environmental pollution in a reliable, specific, and
sensitive way. In this review, the current status of different types of microbial biosensors and
mechanisms of detection of various environmental toxicants are discussed.

Keywords: Bioreceptors, enzymes, biosensors, pollutants, degradation, transducers