It is
difficult to relate single species behaviours to the
overall ecosystem. Since traditional methods of
microbial ecology require that organisms from an
environment be cultured in the laboratory before they
can be identified and studied, monitoring the effect of
pollutants on the activities of the overall communities
poses a great challenge,because less than 10% of
microorganisms from any environment is culturable
(Baath,1992a; Diaz Ravina et al., 1994; Frostegard and
Baath 1996).