To develop eff ective microbial agents applicable to complex technology for grease wastes utilization, a total of 124 microorganisms were screened for their ability to degrade lipidic compounds. Th e screening yielded fi ve strains (UP2, F2, E13, Kl1 and N3) showing lipolytic activity and rapidly degrading sunfl ower and olive oil, tallow and lard. Among them, strains E13 and N3 were found to have the highest lipase activity and the more intensive rates of the degradation of saturated (palmitic and stearic) and unsaturated (oleic and linoleic) fatty acids and triglycerides containing these fatty acids. Th e strains were obtained from the culture collection of JSC "Biocentras" and identifi ed as Enterobacter aerogenes E13 and Arthrobacter sp. N3. When a mixed culture of strains E. aerogenes E13 and Arthrobacter sp. N3 was grown in a mineral medium containing 0.5% of sunfl ower oil, the hydrolysis products were diglycerides, monoglycerides and free fatty acids. Moreover, the mixed culture was consuming these hydrolysis products during cultivation at 30 °C. Investigation of lard biodegradation in black soil showed that a mixed culture of strains E. aerogenes E13 and Arthrobacter sp. N3 degraded lard about 7 times more intensively than indigenous soil microorganisms (aft er six weeks of degradation in black soil, the concentration of lard was reduced by 87.5 and 8.0%, respectively). Th erefore, the mixed culture of strains E. aerogenes E13 and Arthrobacter sp. N3 may be used for an eff ective grease waste reduction in a complex cleaning technology.

Journal of Environmental Engineering and Landscape ManagementPublication details, including instructions for authors and subscription information: Abstract.A new composting technology of waste with high fat content was developed in JSC "Biocentras". The composting technology of fat-contaminated waste is based on the use of fat-oxidizing microorganisms. Developed technology is commended for cleaner production/pollution prevention approach as well as meets strict environmental and hygiene requirements. The composting process was investigated for the process optimization by applying the response surface methodology. Values of parameters of composting process were monitored in lab-scale composters. The optimal composition of the composing mixture was determined: the initial fat content -5%, the concentration of bacterial preparation cells -10 9 CFU/g, the quantity of structural materials -9.5%. Fat degradation rate slowed down 3 times if the initial fatty concentration increased from 5% to 20%. Concentrated fatty-waste disposal site prototype was designed. Composting process duration lasted 1 to 1.5 year.

The biological oil- polluted soil treatment method is used widely; however it is not effective enough because the microorganism‟s metabolism is affected by seasonal temperature fluctuation. Besides, soil remediation processes are very slow because of low solubility of oil and oil products in water. Biological surface active compounds show promising results in oil-polluted soil bioremediation. Three hydrocarbons degrading microorganisms strains, showing high emulsification activity were selected.

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.