This paper describes the problem of oil pollutant re moval and the use of Acinetobacter genus microor ganisms in oil biodegradation. As part of the experi ments, Acinetobacter genus microorganism strain with the best ability to degrade crude oil and fuel oil in saline waters was selected from the microorganism collection of JSC "Biocentras". The impact of environmental con ditions (salinity, temperature, pH, substrate concent ration) on this strain's viability and the efficacy of its oil degradation processes were evaluated. The most ef ficient degradation of oil products by Acinetobacter ge nus bacteria was at temperature of 30 °C, in a pH range of 7-8, in model ocean water of 35 ‰ salinity.

Creosote oil is a complex mixture of hydrocarbon compounds obtained from high temperature distillation of coal tar. It is used for over 100 years as a fungicide, insecticide, miticide, and sporicide to protect wood and is applied by pressure methods to wood products, primary utility poles and railroad ties. This treated wood is intended for exterior or outdoor uses only. Its commercial uses include railroad ties 70%, utility poles 15-20%, and other miscellaneous commercial uses 10-15%. Composition of the creosote depends on the source and it has typically 85% polycyclic aromatic hydrocarbons (PAHs), 10% phenolic compounds, and 5% heterocyclic. Between 20 and 40% of the total weight of typical creosote can be attributed to the 16 PAHs defined as priority pollutants by the United States Environmental Protection Agency (EPA). The production of creosote in the European Union (EU) has been estimated to be approximately 60.000-100.000 t per year. The presence of the toxic PAHs and phenolic compounds make creosote treated wood harmful for the environment at the end of its service life and direct or indirect human exposure to creosote treated wood may cause carcinogenic affect to kidney, liver, bladder, eyes and skin. In this presentation we review creosote environmental pollution toxicity and possibilities of remediation.

Accidental or deliberate spillage of crude oil into the environment is leading to serious pollution problems. Therefore, these areas of oil pollution can be decontaminated by microorganisms. However, biological degradation capabilities of oil and its derivatives, also their effect on living organisms and on the environment varies. Microorganisms that degrade oil hydrocarbons are found in almost all types of soil; however, their existence does not guarantee the effective degradation of oil pollutants. In order to evaluate capabilities of newly developed SORBENT bacterial preparation (SBP) to degrade heavy hydrocarbons, degradation dynamics was observed in different soil types: loam, clay and sand, using crude oil and fuel oil mixture (1 : 1). Therefore, correlation between the intensity of oil component degradation and temperature as well as a correlation between the intensity of oil fraction degradation and the amount of SBP were evaluated. According to experimental data, soil samples polluted with heavy hydrocarbons and treated with SBP, during the first 9 weeks of biodegradation were composed of: up to 20-30% of alkanes, 30-50% of aromatic compounds, 50-60% of resins and 9-44% of asphaltenes. The investigations revealed that less polluted soil (up to 100 g/kg) treated with microorganisms was degraded almost 6 times better than heavily polluted soil (350 g/kg). Therefore, it can be stated that SBP is very effective in the degradation of all types of oil hydrocarbons, including resins and asphaltenes, which are known as the most difficult ones to degrade. This paper reflects findings from the EU funded 7th Framework programme project "SORBENT" (232533).

Biological oil hydrocarbons degradation is a complicated process, influenced by hydrocarbons properties, microorganisms and environmental conditions. The aim of this work was to select microbial strain, capable of degrading heavy branched hydrocarbons for further application in environment remediation and bio-cracking. Also, it was necessary to select optimal conditions (temperature, pH, concentration and etc.) for selected microbial strain degrading heavy branched hydrocarbons. Since crude oil and its products are mixtures of various hydrocarbons, at the first step of selection the ability of the strains to degrade individual hydrocarbons was investigated. Squalane was used as a test substrate. 10 microbial cultures belonging to genus Arthrobacter and obtained from culture collection of JSC “Biocentras” were used for the investigations. Gas chromatography analysis revealed that Arthrobacter sp NJ5 strain had the highest effectiveness (67%) in degradation of heavy branched oil hydrocarbon (Squalane) to shorter chain intermediates. So, Arthrobacter sp NJ5 could be applied in bio-cracking. For the application in industry, more detailed analyses are needed.

One of the perspective areas for biotechnology application is the clean-up of environment contamination by oil hydrocarbons. The above biotechnology is based on the ability of some microorganisms to degrade crude oil and oil products. Among the oil hydrocarbon degrading microorganisms, the bacteria of genus Arthrobacter and genus Acinetobacter are especially attractive for biotechnological applications, as they are widespread in the environment and are able to survive in extreme conditions (Levišauskas et al., 2004;Towner, 2006). The aim of this work was to select optimal conditions (inoculum age, inoculum vo lume, temperature, pH, concentration) for microbial strains degrading crude oil and to research how SARA fractions (saturated compounds, aromatic compounds, resins, asphaltenes) change in composition after crude oil degradation in optimal conditions. Two strains Acinetobacter sp. Pr82 and Arthrobacter sp. M1 were obtained from the culture collection of JSC "Biocentras" and used for investigations. Research results show the best degradation intensity of saturated hydrocarbons by Acinetobacter sp. Pr82 and Arthrobacter sp. M1; much lower degradation was of aromatic compounds, resins and asphaltenes.