The preservation of microbial DNA in archived soils of various genetic types.

This study is a comparative analysis of samples of archived (stored for over 70-90 years) and modern soils of two different genetic types-chernozem and sod-podzolic soils. We revealed a reduction in biodiversity of archived soils relative to their modern state. Particularly, long-term storage in the museum exerted a greater impact on the microbiomes of sod-podzolic soils, while chernozem samples better preserved the native community. Thus, the persistence of microbial DNA in soil is largely determined by the physico-chemical characteristics that differ across soil types. Chernozems create better conditions for the long-term DNA preservation than sod-podzolic soils. This results in supposedly higher levels of biodiversity conservation in the microbiomes of chernozem with preservation of major microbial taxa dominant in the modern (control) soil samples, which makes archived chernozems a promising object for paleosoil studies.