Bacterial Communities of Regressive Spots in Ombrotrophic Bogs: Structure and Functions

— This research analyses the structure and functions of bacterial communities of regressive spots in ombrotrophic bogs. Algal biomass was found to predominate in the biomass structure of regressive spots, while fungal mycelial biomass predominated in the layers of non-regressive ombrotrophic bog peat. A number of bacteria in regressive spots determined by direct counts was three to seven times higher than the one in non-regressive ombrotrophic bog peat. Although the Proteobacteria and Acidobacteria predominated in the samples studied, their shares in non-regressive ombrotrophic bog peat were lower. Members of the phylum Verrucomicrobia predominated in the regressive spots, while in non-regressive raised bog peat they were among the minor components. It was found that the epiphytic-saprotrophic bacterial communities were dominated by bacilli during the dry season and by the proteobacteria during the wet season. According to the results of the 16S rRNA gene sequencing, the bacteria found were identified as Chryseobacterium , Stenotrophomonas , Pseudomonas , and Chromobacterium . Physiological activity of the bacterial communities in regressive spots was similar to that of fen peat communities due to abundance of bacteria using easily accessible polymers. Nitrogen-fixing activity of the bacterial communities was found to be significantly higher in regressive spots than in non-regressive ombrotrophic bog peat.