Surface tension activity of bacterial strains from the species Bacillus isolated from soil saturated with engine and technical oils were investigated. Bacterial identification and measurements of the surface tension in the culture filtrates of the bacterial strains were carried out. For comparision, a Bacillus strain from the Culture Collection at the Dep. of Food Technology and Storage was used to compare the surface tension activities of the used Bacillus strains. The best strain decreased the surface tension of the medium by 23.6 %, i.e. from 69.85 to 53.35 mN/m.