Bacterial composition of different types of soils of Georgia

Abstract

Soil is a dynamic system in which relationship among soil minerals, organic substances and living organisms constantly exists. Microflora is an integral part of complex system of soil in which bacteria are the largest group of soil microbes, both by total number and diversity. The study of bacterial composition of 18 types of soils from Western, Eastern and Southern Georgia has shown that soils are distinguished both by total number of bacteria and by frequency of occurrence for certain investigated bacterial genera (Bacillus, Pseudomonas, Rhodococcus). Bog (7.87 Log10 CFU/g) and brown forest (7.22 Log10 CFU/g) soils of Western Georgia, black (8.80 Log10 CFU/g) and grey cinnamonic (7.91Log10 CFU/g) soils of Eastern Georgia and Chernozem (10.92 Log10 CFU/g) of Souther Georgia are the richest by total number of bacteria. Bacteria of the genus Bacillus prevailed in most of studied soils (yellow, bog, yellow podzols, mountain meadow, saline, meadow cinnamonic, cinnamonic, mountain forest meadow, mountain meadow, meadow grey cinnamonic, grey cinnamonic, chernozem, brown forest black, raw carbonate soil in Western Georgia and brown forest in soil of Southern Georgia); bacteria of the genus Pseudomonas – in alluvial and brown forest soils both of Western and Eastern Georgia, and bacteria of the genus Rhodococcus – in yellow brown forest, red and Raw carbonate soil of Eastern Georgia. All three groups of bacteria occur at the same frequency only in black soil.