Dominant bacterial genera of microbiota of chernozems of the forest-steppe zone

BACKGROUND: Bacterial community plays a significant role in maintaining homeostasis and fertility of chernozems. Analysis of its components allows us to identify the dominant taxonomic groups, the ecological preferences of the species that form their basis, and helps to focus efforts on creating biological products and tests aimed at monitoring and enhancing fertility. AIM: The aim of this study is to identify bacterial genera that dominate the microbiota of Chernozems in the forest-steppe zone of the European part of Russia, and to trace the influence of land use, summer season phase, agrochemical parameters and interactions with each other on their abundance. MATERIALS AND METHODS: In the Belgorod region, 10 samples of arable and non-arable chernozems were taken twice during the summer. Based on metabarcoding data, the percentages of genera in bacterial communities were obtained. An agrochemical analysis was carried out with the calculation of correlation coefficients between the chemical indicators of chernozems and the proportions of bacterial genera. An analysis of correlations between bacterial genera was carried ut as well. RESULTS: Dominant genera include Sphingomonas, Rubrobacter, Gemmatimonas, Bradyrhizobium, Haliangium and others. Under soil conditions, the proportion of representatives of the genera Sphingomonas and Gemmatimonas shows a strong positive correlation with nitrate nitrogen concentration, and the proportion of the genus Bradyrhizobium shows a strong negative correlation with phosphorus concentration. The largest number of positive correlation interactions with other genera was found for Nocardioides, Mycobacterium, Streptomyces, and Solirubrobacter. CONCLUSIONS: The stability of the set of bacterial genera dominant in the chernozems of the forest-steppe zone of Russia in different environmental conditions (plowed and unplowed areas), as well as over time (June and August) was shown. A number of representatives belonging to the genera Sphingomonas, Gemmatimonas, Bradyrhizobium and others are strongly dependent on the concentrations of nitrogen and phosphorus fertilizer components. Representatives of actinomycetes and mycobacteria are closely involved in positive correlation interactions among bacterial genera.