Effect of heavy metals on soil microbial quality of an abandoned mining area Sidi Kamber, North-East of Algeria

摘要

The ecological importance of soil bacteria is not limited to their number or biomass, although these parameters contribute greatly. Indeed, their main asset lies in their great genetic and functional diversity.This study aims to determine heavy metal contamination levels of the soils of an abandoned mining area of Sidi Kamber (Skikda), impact of heavy metals on bacterial communities and the possible risks that can affect the ecological balance of this area. Soil samples from three zones (Zone A, B and C) were collected from the top layer (0–20 cm) of mining area. Chemical analysis (pH, organic matter, total organic C, total N, available P, and cation exchange capacity, metal content of (Pb, Cu, Cd, Zn and Ni) and bacterial analysis were carried in center for biotechnology research CRBt. Our results show that the mining area is characterized by an acid pH. Significant variations were observed for edaphic parameters (organic matter, total organic C, total N, available P and cation exchange capacity) between three sampling zones. The overall area was severely polluted with Cu, Cd, Pb, Ni and Zn with a total concentration far exceeding international standards. The bacterial load and diversity were relatively high with a significant variation between the three zones. The PCA analysis of the soil's characteristics indicates that the organic matter and the cation exchange capacity affect the distribution of the metallic trace elements in the soil and allowed us thus to a clear separation of the studied zones.