title: Resistance to and accumulation of heavy metals by actinobacteria isolated from abandoned mining areas.
abstract: Accumulation of high concentrations of heavy metals in environments can cause many human health risks and serious ecological problems. Nowadays, bioremediation using microorganisms is receiving much attention due to their good performance. The aim of this work is to investigate heavy metals resistance and bioaccumulation potential of actinobacteria strains isolated from some abandoned mining areas. Analysis of mining residues revealed that high concentration of zinc "Zn" was recorded in Sidi Bouatman, Arbar, and Bir Nhass mining residues. The highest concentration of lead "Pb" was found in Sidi Bouatman. Copper "Cu," cadmium "Cd," and chromium "Cr" were found with moderate and low concentrations. The resistance of 59 isolated actinobacteria to the five heavy metals was also determined. Using molecular identification 16S rRNA, these 27 isolates were found to belong to Streptomyces and Amycolatopsis genera. The results showed different levels of heavy metal resistance; the minimum inhibitory concentration (MIC) recorded was 0.55 for Pb, 0.15 for Cr, and 0.10 mg·mL(-1) for both Zn and Cu. Chemical precipitation assay of heavy metals using hydrogen sulfide technic (H2S) revealed that only 27 isolates have a strong ability to accumulate Pb (up to 600 mg of Pb per g of biomass for Streptomyces sp. BN3).
authors.affiliation: Environmental Microbiology and Toxicology Unit, Laboratory of Biology and Biotechnology of Microorganisms (LBBM), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Soraia
authors.initials: S
authors.lastname: El Baz
authors.affiliation: Environmental Microbiology and Toxicology Unit, Laboratory of Biology and Biotechnology of Microorganisms (LBBM), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Baz
authors.affiliation: Environmental Microbiology and Toxicology Unit, Laboratory of Biology and Biotechnology of Microorganisms (LBBM), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Mustapha
authors.identifier: 0000-0001-7949-5592
authors.initials: M
authors.lastname: Barakate
authors.affiliation: Environmental Microbiology and Toxicology Unit, Laboratory of Biology and Biotechnology of Microorganisms (LBBM), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Lahcen
authors.identifier: 0000-0001-7998-3596
authors.initials: L
authors.lastname: Hassani
authors.affiliation: Laboratory of Hydrobiology, Ecotoxicology and Assainissement (LHEA), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Abdelhay
authors.initials: A
authors.lastname: El Gharmali
authors.affiliation: Environmental Microbiology and Toxicology Unit, Laboratory of Biology and Biotechnology of Microorganisms (LBBM), Faculty of Sciences Semlalia, Cadi Ayyad University, P.O. Box 2390, 40000 Marrakech, Morocco.
authors.forename: Boujamâa
authors.initials: B
authors.lastname: Imziln
mesh_terms: D039903:Actinobacteria / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism*; D008906:Mining
chemical_list: D019216:Metals, Heavy