Microbial sensors are a class of the cell-based sensors. The advantages of using the whole cells in place of isolated enzymes in sensor technology are :
(i) whole tissue or microbes are a source of a large quantity of undamaged en zyme;
(ii) enzymatic pathways inherent in tissue cells may be difficult or impossible to reproduce outside the cell;
(iii) enzymatic reactions are already optimized in intact tissues; (iv) all cofactors, substrates, and so on for enzymatic reactions are available in
whole tissues; (v) stability of the enzyme is not compromised by the purification procedures; (vi) low cost - no need to purify enzyme, substrates, cofactors, and so forth; (vii) permits the detection of the effect of various groups of substances via their
action on certain cell loci or the overall metabolism of the cell; (viii) longer useful lifetime.