Population number, viability, and taxonomic composition of the bacterial nanoforms in iron-manganic concretions

It is shown for the first time that a significant part of the bacteria (up to 40%) in the iron-manganic concretions of soddy-podzolic and soddy meadow soils are represented by nanoforms; their number reaches 600–700 million cells/g. Judging from the specific luminescent coloration, the fraction of viable cells among the bacterial nanoforms is very high in the concretions and amounts up to 88–99%. For the first time, the following phyla were identified among the bacterial nanoforms in the concretions with the use of the FISH method: Alphaproteobacteria, Betaproteobacteria, Gammaproteobateria, Deltaproteobacteria, Acidobacteria, and Planctomycetes. The Gammaproteobacteria phylum predominated in the concretions from the soddy-podzolic soil, and the Deltaproteobacteria phylum predominated in the concretions from the soddy meadow soil. In the alluvial meadow soil, the Alphaproteobacteria, Betaproteobacteria, and Acidobacteria phyla were found. The significant number and portion of bacterial nanoforms in the concretions, their high vitality, and their taxonomic diversity allow us to conclude that the bacterial nanoforms play an important role in the processes taking place in the concretions.