Bacterial Communities: Interaction to Abiotic Conditions under Effect of Anthropogenic Pressure

Abstract

Relationships between different microorganisms’ groups and the soil environment are reversible, and the state of the soil and its provided services can also change the structure and abundance of microorganisms as well as that microorganisms can affect soil conditions. The aim of our research was to analyze the physical and chemical properties of differently formed agroecosystems, which are affected by different anthropogenic pressures and to compare how bacterial composition differ in totally different environments. It was established that different soil microorganisms’ physiological groups significantly correlated with chemical and physical soil properties: atmospheric nitrogen-fixing bacteria showed a positive correlation with soil pHKCl, Nsum, P2O5, and soil bulk density; meanwhile, soil porosity, and the K2O amount in the soil negatively affected the population of atmospheric nitrogen-fixing bacteria. The same tendencies were inherent to actinomycetes and ammonifying bacteria. Micromycetes showed a negative trend with soil pHKCl, showing that soils with lower pHKCl are characterized by a higher abundance of micromycetes. Analysis of the taxonomic diversity of soil microbes reveals that the bacterial communities were dominated by two main species of bacteria: Betaproteobacterium and Candidatus Saccharibacteria. Bacterial identification shows that the main bacterial species were the same in all analyzed sampling places despite the different anthropogenic activities, parent material, and other abiotic conditions. Only a few species were identified in different soil groups, and it may be assumed that those groups could be potential bioindicators for specific soil types, but more in depth research is needed to confirm this hypothesis.