Screening for phenol-degrading bacteria in the pristine soils of south Siberia

Abstract

Densities of phenol-degrading bacteria ranging from 102 to 106 CFU g-1 were found in the rooting zone of pristine soils from several ecosystems typical for the Altai Mountains by the simple spread plate method. An absolute majority of the isolates were biochemically and on the basis of their fatty acid profiles assigned to the genus Pseudomonas. At initial phenol concentrations of up to 5.3 mM they were able to degrade phenol completely and some of them even up to 8.0 mM. To our knowledge, the soils never came into contact with any product of industrial acitivity. The study shows that it is easy to isolate phenol-degrading bacteria from various spristine soils and that there is a natural capacity to degrade phenolic molecules. The results support the idea that unaffected environments can serve as a source of bacterial strains for purposes of bioremediation.