Dumanska T. Biological properties of bacteria degrading oil hydrocarbon

The thesis is devoted to investigation of biological properties of active strains -destructors of hydrocarbons as well as to determination of efficiency of preparations for purification of oil polluted environment, created on their basis. Active destructors of hydrocarbons had been selected on the screening of strains, isolated from oil polluted soil and collection strains, which were able to assimilate n-alkanes. These strains had been identified as Acinetobacter calcoaceticus, Gordonia rubropertinctus and Rhodococcus erythropolis species. They are able to assimilate the wide spectrum of hydrocarbons, are not mutual antagonists, have no phytotoxic and pathogenic properties. It has been found that the assimilation of hydrocarbons by G. rubropertinctus IMV Ac-5005 and R. erythropolis IMV B-7012 strains was accompanied by the increasing of cell surface hydrophobicity in 4-25 times as well as by the syntheses of cell-bounded surface-active substances (bioSAS) with emulsifying properties, which were able to form stable emulsions of "butter in water" type. Such glycolipids as mono- and dimicolates of trehalose were the dominating components of bioSAS of these strains. The assimilation of hydrocarbons by highly hydrophobic A. calcoaceticus IMV B-7013 strain resulted in the decrease of hydrophobicity in 1.4 times and the syntheses of extracellular bioSAS, which form the stable emulsions of "water in butter" type. A. calcoaceticus IMV B-7013 bioSAS consisted of cadrohydrates, proteins and lipids. The total amount and composition of these components depended on the utilized substrate. The joint cultivation of these strains increased the destruction of hydrocarbons by 6-15% which amounted 76.0-97.8% and remained high at mineralization of medium to 4.0 % of NaCl and pH 6.0-8.0. The preparations Ekolan and Rodoil, created on the basis of these strains and oil sorbents, reduced the concentration of hydrocarbons in water by 89.6% during 7 days, in soil - by 92.7% during 3 months and in oil slurry - by 92.1% during 6 months. Ekolan and Rodoil in the proposed by us norms of application in the polluted environment had no negative action on the hydrobionts of freshwater ecosystems.