The Structural and Functional State of Soil Microbiota in a Chemically Polluted Environment

The structural and functional diversity of the main ecological trophic groups of soil microorganisms in meadow soils of the Central Urals anthropogenically contaminated with heavy metals was studied. The increase in the total numbers of these microorganisms in technozems, in comparison with those in agrozems, is due to the higher abundance of iron-reducing, denitrifying, nitrogen-fixing, and sulfate-reducing bacteria, an increase in cellulolytic activity, and the dependence of these characteristics on the toxic load of the soil. A reductive structure of the microbial community with the predominance of r-strategists, which reflects earlier stages of microbiocenoses succession under soil contamination, is formed under soil pollution with heavy metals. © 2017, Pleiades Publishing, Inc.Ural Branch, Russian Academy of Sciences: 12-I-4-2051ACKNOWLEDGMENTS This work was supported by the Government of Sverdlovsk oblast, the Russian Foundation for Basic Research (project no. 13-04-96056-r_ural_a), and a Program of the Presidium of the Ural Branch, Russian Academy of Sciences (project no. 12-I-4-2051)

Soil microbiocenosis as an indicator of stability of meadow communities in the environment polluted with heavy metals

The soil microbiota, a key component of natural ecosystems, is considered as a factor determining the stability of meadow communities. The diversity and abundance of the main ecologically significant groups of microorganisms in meadow soils have been studied along a gradient of long-term soil pollution with heavy metals in the Middle Urals. The results provide evidence for stability of the microbial assemblage formed in these soils. It has been found that the functional activity of certain physiological groups of microorganisms (nitrogen-fixing, denitrifying, and cellulolytic bacteria) and the respiratory activity of microbial communities are stimulated under conditions of heavy-metal soil pollution. Probable effects of the observed changes on mineralization of plant remains in meadow communities are discussed. © 2014 Pleiades Publishing, Ltd.13 04 96056ACKNOWLEDGMENTS This study was supported by the Russian Founda tion for Basic Research (project no. 13 04 96056 r_ural_a), Scientific School Support Program (project no. NSh 5325.2012.4), and the Presidium of the Ural Branch of the Russian Academy of Sciences (project no. 12 I 4 2051)