Living micro-organisms are constantly exposed to environmental stresses, most prominently pollution. These stresses exert a selective pressure on species and only these which have a genotype which allows them to remain viable endure. Heavy metals and some other pollutants present in the environment can induce stress responses in bacteria which result in the presence and diversity at several genes involved in metabolic degradation and detoxication pathway, including cat, catG, czcA and nccA. The diversity of these genes was examined with the goal of identifying the expression of alternate genes, analyzing the DNA sequence of the gene domains, and determining the microbial diversity of cultivatable species.