Tatyana Glebovna Dobrovolskaya

This research based on both direct and seeding methods revealed high bacteria concentration on bogs plants: Carex nigra, Eriophorum vaginatum, Drosera rotundifolia, Ledum palustre. There was identified a correlation between bacteria number and investigated plants’ organs. Proteobacteria dominated in phyllosphere, bacilli and actinomycetes - in rizoplane and rhizospheric soil. Representatives of the genus Pseudomonas and Erwinia dominated in phyllosphere. Nitrogenase activity of bacterial populations in rhizosphere soil was high and reached the maximum in Drosera rhizospheric soil.

For the first time, the ratio of large taxa and the genera spectrum in the prokaryotic complex of the rhizosphere soil under typical plants of bogs were revealed by high-performance sequencing. The dominance of acidobatheria and alpha-proteobacteria was established with a low proportion of other taxa (less than 10%). Among the 24 bacterial genera found, representatives of the phylums Acidobacteria and Actinobacteria, as well as the Alphaproteobacteria class, predominate. Common bacterial genera were identified in rhizosphere soil under plants and surface layers of peat. Representatives of most of these bacteria are adapted to grow in an acidic environment and at low temperatures. Their functioning is determined by the use of various sugars, polysaccharides, aromatic compounds, organic and amino acids. Bacteria of the genera Cytophaga and Acidothermus are capable of cellulose destruction, Occallatibacter - chitin, Nocardia - humic substances and lignin.

This article provides an analysis of structural and functional indicators of bacterial complexes taken for examination from the complete profile of the fens that form part of “Klukvennoye” and “Karbyshevskoye” wetland systems in the Tomsk Region. In the fens bacteria was found throughout all the profile. The number of bacteria was high and varied from 27 to 78 ´ 10⁹ cells/g of dry peat. This data was obtained by direct method using fluorescence microscopy. The high count of the saprotrophic bacteria (reaching up to 10⁸-10⁹ CFU/g of dry peat) was found by the plate method. Those results allowed to identify a trend, showing that the number of saprotrophic bacteria increased down the fen profile.  The results of this study give an opportunity to state for the first time that the index k ( k is a dimensionless universal characteristic of natural prokaryotic communities, k stands for microscopy/plate) in fen profiles does not increase, but decreases with depth. The following bacterial cultures were identified and isolated from the fens studied (those cultures were attributed to 10 taxa): Bacillus, Streptomyces, Arthrobacter, Microbacterium, Pseudomonas, Pedobacter, Flavobacterium, Dyadobacter, Janthinobacterium, Myxobacteriales. Bacterial cultures, representing Bacillus and Streptomyces genera, were dominant in the acrotelm. At the same time Pseudo-monas, Dyadobacter and Arthrobacter dominated in the catotelm. The functions of bacterial genera and species, identified by molecular biological methods, were described. A study of nitogen fixation, nitrogen decline and methanogenesis showed that bacteria were in a viable state and were able to remain active throughout the entire peat profile.