NA Kireeva, YM Tarasenko, TS Onegova, Bashkirian State University

In areas of oil extracting and oil processing the oil is the main contaminant of environment. Getting in soil, the oil changes its physical and chemical properties, reduces fertility. One of the most harmless regeneration methods of such contaminated soils is hydrocarbon oxidizing microorganisms (HOM) in a complex with the different bioadditions using.

In the given work the results of preliminary model study of microorganisms influence of hydrocarbon oxidize microorganisms and bioaddition ‘’Bilvitamil’’ with surface-active matter on oil biodestruction acceleration in soils are presented.

In vegetative capacities wood gray soil, contaminated with crude oil and mineralized sewage(0-20 cm depth) was put. Uncontaminated wood gray soil was used as a control. The hydrocarbon oxidize microorganism complex and bioaddition "Bilvitamil" coupled with surface-active matters were tested as oil destruction stimulaters. Complex HOM was extracted from oilfield sewage. It consists of three strains, concerning to Pseudomonas, Arthrobacter genuses. The complex was brought in amount of 10⁶ cells /g soil. The biological addition "Bilvitamil" is an active silt of microbialogical productions. It consists HOM, vitamins, nitrogen-bearing components and other bioactive substances. It was brought in at the rate of 20 t/ha or 13,32 g / 1000g of soil. Neonol Af-14 – the surface active matter – reduced oil contaminated soil hydrophobia and intensify oil destruction process. Neonol was brought as water solution at the rate of 50 kg / ha. Number (HOM), enzyme dehydrogenize activity ,soil phytotoxic and residual contents were used as soil bioactivity parameters.

Preliminary field (on a place of oil pipeline bursting) and the laboratory researches of HOM complex and bioaddition influence on oil contaminated soil have shown, that these methods accelerate soil restoration, promote enriching of its ecological state and regeneration of a biological activity.

Nailya A. Kireeva, Gulshat F.Yamaletdinova, Bashkirian State University

Contamination by oil products, as well as the contamination by oil, brings to change of physicochemical and biological properties of soil. Depending on chemical composition and concentration the oil products ambiguously influence on soil enzymatic and microbiological activity. In laboratory experiments the influence of contamination by different oil products in different doses on the activity of enzymes (sulfiteoxydase, sulfitereductase, sulfideoxydase and sulfatereductase) and on number of microorganisms of sulfur exchange of dark-grey forest soil was studied. For oil products biodegradation process acceleration two bacterial preparations were used: Bacispecin and Devoroil. Bacispecin is a monopreparation made on the basis of natural strain Bacillus sp. 739; Devoroil is an association of three strains of hydrocarbon oxidizing microorganisms. The preliminary research have shown, that diesel oil and engine oil in low concentrations (0,5 % from the mass of the soil) originally stimulate activity of sulfiteoxydase, sulfitereductase and sulfideoxydase; the activity sulfatereductase decreases. The increase of concentration of these oil products in soil brings to lowering of activity of studied enzymes. Contamination by the benzine only the activity sulfideoxydase rises, the activity of remaining enzymes reduces in inversely proportion with the dose of pollutant.The appearance of oil products in soil stimulates the growth of acidofuge tiobacilli. The increase of the dose of benzine suppresses the growth of these microorganisms. The contamination by diesel oil and engine oil in different doses influences on number of thiobacterium differently. In all variants of experiences sulfate-reducing bacteria were not detected. The appearance of microbiological preparations reduces the percentage of residual hydrocarbons of oil (first of all of last cuts). The activity of oxidoreduction enzymes is reverted to a datum level.

Dr Samina Siddiqui, Centre for International Postgraduate Studies, Germany

Hydrocarbon contamination in soils may be toxic to plants and soil microorganisms and act as a source of groundwater contamination. The objective of the study was to evaluate the fate of adding diesel in soils A and B with or without added nutrients. The soils examined either had or had not a previous history of hydrocarbon contamination. Particular aspects examined were soil respiration, changes in microbial population, breakdown of diesel hydrocarbons and phytotoxicity to germination of ryegrass. Soil respiration was measured as evolved CO2. Bacterial population was determined as CFUs in dilution plates and fungal activity was measured as hyphal length. The fate of individual hydrocarbons was determined by GC-MS after extraction with dichloromethane. When diesel was added to soil A which had no previous history of hydrocarbon contamination at 50 mg g-1, the respiration response showed a lag phase of 6 days and maximum respiration occurred at day 11. The lag phase was typically 2 days and maximum respiration occurred at day 3 in soil B which had a previous history of hydrocarbon contamination. After the peak, respiration decreased up to 20 days in both soils. Thereafter, respiration became more or less constant but substantially greater than the control. N&P addition along with diesel did not reduce the lag phase but increased the respiration over the first 20 days of incubation. Diesel addition with or without N&P increased the bacterial population 10 to 100 fold but fungal hyphal length did not increase. Removal of inhibition to germination of perennial ryegrass was linked to the decomposition of nC10 and nC11 hydrocarbons and took from 11 to 30 days in soils B and A.