Resistance to and Accumulation of Heavy Metals by Actinobacteria Isolated from Abandoned Mining Areas

Table 3

Growth percentages of actinobacteria isolated from mining areas.

Heavy metal	Mining areas	Number of actinobacteria isolated	Concentration of heavy metals
			0.05	0.15	0.25	1
			mg⋅	mg⋅	mg⋅	mg⋅
Lead	Bir Nhass	30	100	100	56.67	—
	Sidi Bouatman	8	100	100	100	—
	Tenfit mine	21	100	52.38	9.52	—
	Total	59	100	84.13	55.40	—
Cadmium	Bir Nhass	30	—	—	—	—
	Sidi Bouatman	8	—	—	—	—
	Tenfit mine	21	—	—	—	—
	Total	59	—	—	—	—
Copper	Bir Nhass	30	3.33	—	—	—
	Sidi Bouatman	8	25.00	—	—	—
	Tenfit mine	21	61.90	—	—	—
	Total	59	30.08	—	—	—
Zinc	Bir Nhass	30	3.33	—	—	—
	Sidi Bouatman	8	75	—	—	—
	Tenfit mine	21	23.81	—	—	—
	Total	59	34.05	—	—	—
Chromium	Bir Nhass	30	100	—	—	—
	Sidi Bouatman	8	100	—	—	—
	Tenfit mine	21	100	—	—	—
	Total	59	100	—	—	—

Results are expressed in percentage of strains grown on culture medium with metal per total tested actinobacteria from each mining residue.
(—): no tolerant strains.