Prokaryotic communities of technozems of the spoil heaps of Kursk magnetic anomaly

Abstract

Background. Spoil heaps chronosequences are convenient models to analyze the succession of microbiome during restoration of anthropogenically disturbed landscapes. The investigation of the heavy metal content in lands with mining activity, can be used as an indicator of ecosystem recovery.
 Materials and methods. Objects were technozems of 1-year, 25- and 50-year-old embryonic soils, and control soil under forest. Quantitative polymerase chain reaction (qPCR) and NGS-sequencing of V4 region of 16S rRNA gene were applied. Results. During the soil-forming process, an increase organic carbon and nitrogen, as well as a gradual increase archaeal 16S rRNA gene copies and in the number of Bradyrhizobiaceae, Blastocatellaceae, Xantobacteriaceae. Although we found a number of taxa that increased during soil-forming process (Thaumarchaeota, Bradyrhizobiaceae, Blastocatellaceae, Xantobacteriaceae), technozems of different ages had a similar structure and diversity of prokaryotic communities, differing from a nature soil. Biodiversity analysis revealed that technozems generally had a similar structure and diversity of prokaryotic communities, significantly differing from the mature soil a specific clusterization of microbiomes. The HM contents and bacterial abundances remained at the same level in chronosequence.
 Conclusions. The 50 years of soil development on overburden spoil heaps is not enough for the recovery from HM contamination and restoration of soil ecosystem functioning.