Physicochemical and molecular characterization of heavy metal–tolerant bacteria isolated from soil of mining sites in Nigeria

Journal of Genetic Engineering and Biotechnology

Table 6 Heavy metal tolerance of the bacterial isolates obtained from soil of mining areas in Zamfara State

Heavy metal	Conc. (ppm)	Aeromonas sp.	Aeromonas sobria	Alcaligenes faecalis	Bacillus spp.	Enterococcus sp.	Leptothrix ginsengisoli	Micrococcus sp.	Pseudomonas sp.	Streptococcus sp.
Pb	˂ 6.0	+	+	+	+	+	+	+	+	+
Pb	≥ 6.0	+	+	+	−	−	+	−	−	−
Cd	˂ 6.0	+	+	+	+	+	+	+	+	+
Cd	≥ 6.0	+	+	+	−	−	+	−	−	−
Cr	˂ 6.0	+	+	+	+	+	+	+	+	+
Cr	≥ 6.0	+	+	+	−	−	+	−	−	−
Cu	˂ 6.0	+	+	+	+	+	+	+	+	+
Cu	≥ 6.0	+	+	+	−	−	+	−	−	−