Abstract
A topical research trend in ecological biotechnology is the search and study of microorganisms-destructor resistant to additional pollutants and growth-stimulating to remediant-plants. Four strains of hydrocarbon-oxidizing microorganisms isolated from soil samples were identified on the basis of cultural-morphological, physiological-biochemical properties and a comparative analysis of the gene encoding 16S rRNA. The bacteria Acinetobacter calcoaceticus UOM 22 and UOM 29, A. courvalinii UOM 35 showed a significant degree of oil biodegradation in a liquid medium at 24 and 8 °C (93.0–95.6% and 78.4–81.1%, respectively). In the same conditions these indicators were 44.8 and 33.7%, respectively for strain Rhodococcus erythropolis UOM 33. All microorganisms grew in the presence of aromatic hydrocarbons (including polycyclic hydrocarbons), were resistant to NaCl (5–7%) and lead ions (1.00–1.25 g/L). They were capable of nitrogen fixation and inorganic phosphate dissolution, indole-3-acetic acid synthesis (150–1416 ng/ml of culture liquid) and hydrolytic enzyme lipase production. We found that A. calcoaceticus UOM 22 and A. courvalinii UOM 35 strains increased the barley seeds germination by 8.6 and 10.5%, as well as A. calcoaceticus UOM 29 and A. courvalinii UOM 35 stimulated the barley root growth by 16.3 and 18.1% respectively. The results of the experiments indicate the possibility of using A. calcoaceticus UOM 22 and UOM 29, and A. courvalinii UOM 35 strains for cleaning oil-contaminated soils, including in combination with remediant-plants.