| Popis: |
Agriculturally used soils (Kastanozems) of experimental fields in the Mashavera Valley in southeast Georgia show various degrees of trace metal contamination (Cd, Cu, and Zn). Therefore, one part of the soils was remediated with iron grit. The effects of the remediation in comparison to nonremediated soils on microbial diversity and activity were analyzed with the single-strand conformation polymorphism (SSCP) and microbial respiratory activity. All topsoils were characterized by neutral to weakly alkaline pH values, high contents of Corg, and clay. The total contents ranged between 0.46 and 5.89 mg kg−1 for Cd, between 1.19 and 81.4 mg kg−1 for Cu, and between 210 and 976 mg kg−1 for Zn. Basal respiration was significantly (p 98 % sequence identity. The phylum Acidobacteria dominated with 57.7 %. Other groups detected were Proteobacteria (a (2.8 %), v (8.5 %), g (14.1 %), d (4.2 %)), Bacteroidetes (5.6 %), Firmicutes (4.2 %), Actinobacteria (1.4 %), and Nitrospira (1.4 %). Furthermore, the results of the SSCP analysis and the Shannon-Weaver indices suggested that microbial diversity was lower in the heavily contaminated soils, but DNA band profiles of the remediated soils were in higher number than in the untreated soils. Due to the remediation, a recovery of the microbial diversity seems attainable. |
