Oil-oxidizing Bacteria Research Articles

Study of biotechnological potential of hydrocarbon-oxidizing bacteria from oil-contaminated soils of the Uzen oil field

Background: Oil-contaminated soils are one of the significant environmental concerns in Western Kazakhstan. Cleaning soils from oil contamination is becoming extremely important. Biological soil treatment, which uses hydrocarbon-oxiding bacteria for microbiological remediation, is a more environmentally friendly and delicate method of soil treatment than any other currently used technology (physical, chemical, biological). One of the important aspects of microbiological remediation is the use of bacteria endomimic to the treated soil. This guarantees the most effective soil purification, as the bacteria perform in relatively optimal conditions for themselves. The soil of the Mangistau region, especially the coastal regions, is distinctive due to its high mineralisation and low moisture content, which have helped to form a specific microflora that is adapted to these conditions. Aim: The study aims to search and isolate highly effective hydrocarbon-oxidizing bacteria that are native to highly mineralized soils of the Uzen oil field. Materials and methods: The research employs a variety of analytical techniques, including water chemistry analysis and infrared spectrometry, as well as the microbiological culture of aerobic bacteria on liquid and dense media in environments (temperature and salinity) that closely resemble their native ecotopes. Results: Four enrichment cultures of hydrocarbon-oxidizing bacteria were obtained, and three pure cultures of oil-oxidizing bacteria were isolated. Their hydrocarbon-oxidizing efficiency has been studied. On the basis of heavy, extremely viscous paraffinic oil from the Uzen field, their hydrocarbon-oxidizing efficiency was examined. Conclusion: In this study, active enrichment cultures of halophilic hydrocarbon-oxidizing bacteria as well as active accumulative cultures of halophilic and moderately thermophilic aerobic bacteria were obtained. These bacteria are capable of oxidising a wide range of hydrocarbons, including high-molecular polycyclic and sulfur-containing compounds. Their high biotechnological potential will be studied in further studies.

HYDROCARBON CONTAMINATION IMPACT ON SANDY SOILS WITHIN THE DZUNBAYAN OIL FIELD (EASTERN MONGOLIA)

The data are presented on the particle-size distribution, content of hydrocarbons, n-alkanes in their composition and the number of microorganisms in the soils of Dzunbayan oil production area (Mongolia, the Eastern Gobi desert steppe). The soils studied are characterized by the dominance of sand and fluid fraction (99.50–99.8%) with particles of 2–20 μm. The soils show alkaline reaction (pH 8.2–8.7), they are slightly saline in the control areas and highly saline (water extract salinity 0.13–2.34‰) near the production well. The content of petroleum hydrocarbons (HC) in soils of the study area varied from 9 to 60 mg/kg, with a maximum near the well. The study of the molecular composition of n-alkanes revealed the dominance of long-chain homologues (66.3–79.2% of the total n-alkanes), occurring at various stages of physicochemical and microbiological weathering. According to a number of features, the microbial community of soils is characterized by a high degree of adaptation to the conditions of the arid zone, salinity, and high pH values; at the same time, these conditions limit the development of typical representatives of soil microbiocenoses, i.e., actinomycetes and, to a greater extent, microscopic fungi. The total number of heterotrophic bacteria (HBGs) in the studied soil samples varied within 1.22–3.49 million CFU/g of soil. The proportion of oil-oxidizing bacteria (NOB) was 12.6–18.9% OBA, which corresponded to the high adaptive capacity of the community to hydrocarbons. Specific climatic conditions, features of soil composition, as well as oil with a predominance of heavy paraffin fractions of the Dzunbayan deposit, characterize the low potential ability of soils to self-purify under the oil pollution.

Studying the Composition and Genesis of Organic Matter in Bottom Sediments of Polluted Small Watercourses in Khabarovsk City Territory

The distribution of organic matter, hydrocarbons, phytopigments, and ecological-trophic groups of microorganisms was studied in the bottom sediments of ten small tributaries of the Amur R. near Khabarovsk. The water showed high concentrations of organic matter, varying from 44.47 to 279.3 mg/L. The concentration of Corg in bottom sediments varied from 1.9 to 23.1% in different types of sediments; the amount of hydrocarbons reached 5081 mg/kg, exceeding the background level by a factor of up to 50. Studies of the molecular composition of hydrocarbons in sediments revealed in some streams the predominance (up to 100% of the total) of light (C8–C13) n-alkanes, typical of oil products and the products of vegetation combustion. High-molecular compounds dominated in HC composition in most watercourses, including n-alkanes, genetically associated with terrestrial vegetation, and heavy fractions of oil products with various levels of microbial degradation. Volatile organic compounds were quantitatively dominated by the products of microbiological transformation (acetaldehyde and methanol). In terms of the concentration of sedimentary pigments (up to 400 µg/g), the sediments of the majority of watercourses belong to the hypereutrophic type. The total abundance of microorganisms in water varied from 2.7 to 488.0 thousand CFU/mL; in sediments, it was distributed symbatically, but ranged from 0.1 to 19.3 million CFU/g. The number of heterotrophic bacteria in bottom sediments correlated with the parameter of overload of the self-purification capacity (r = 0.718), and the number of oil-oxidizing bacteria correlated with hydrocarbon concentration (r = 0.967), thus confirming the indication properties of this bacterial group.

Influence of oil pollution on the activity of hydrolytic enzymes of sod-podzolic soil against the background of the use of biological products

The article presents the results of studies of the effect of biological products based on oil-oxidizing bacteria on the enzymatic activity of soddy-podzolic soil contaminated with oil. Barley (Hordeum sativum L) and wheat (Triticum vulgare L.) were used as phytomeliorants. The effect of different concentrations of oil on the activity of enzymes such as invertase, phosphatase, urease is shown. It was found that the activity of the studied enzymes depended on the concentration of the pollutant and the duration of oil exposure to the soil environment. It is noted that the treatment of oil-contaminated soil with biological products contributes to the restoration of its biological activity.

Состояние бактериопланктона Северного Каспия в современных условиях

Microbiological monitoring of the Northern Caspian proved that for the research period in 2013-2018 the average annual value of the total number of bacteria (TBN) was 1.35 million cells/ml. The TBN maximum value (1.46 million cells/ml) was recorded in 2013, the minimum (1.19 million cells/ml) - in 2014. Concentration of saprotrophic bacteria in the waters of the Northern Caspian during the research period varied from 50.94 thousand CFU/ml in 2013 to 1.66 thousand CFU/ml in 2014. The concentration of saprotrophic bacteria remained practically unchanged 
 within 2014-2018. The values of the ratio of the total abundance of microorganisms and saprotrophic bacteria show the eutrophication of the waters of the North Caspian in 2013 and in 2016, in other periods the water quality corresponded to the readings of an oligotrophic reservoir. The maximum number of oil-oxidizing bacteria (OOB) (8.28 thousand CFU/ml) in the waters of the Northern Caspian was recorded in 2013, the minimum (0.21 thousand CFU/ml) - in 2014. Starting from 2015 there was recorded an increasing number of OOBs and its stabilization until the end of the research period. The ratio of NOB and saprotrophs in water varied from 16.47 to 52.47%. Analysis of microbiological and hydrological-hydrochemical indicators revealed positive correlations of TBN and annual runoff (r = + 0.77), TBN and the content of mineral forms of nitrogen (r = + 0.60), the number of saprotrophic bacteria and nitrogen (r = + 0.83), the amount of NOB and mineral nitrogen and silicon (r = + 0.81). In the long-term aspect, an improvement in the microbiological situation was recorded against the background of a growing total number of bacterioplankton under a simultaneous decrease in the number of saprotrophic and oil-oxidizing bacteria.

Ecological criteria for assessing the content of petroleum hydrocarbons in the main soils of coniferous-deciduous forests and forest steppe.

The effect of pollution of Albicluvisols/Retisols, Calcaric Leptosols, Luvic Phaeozems, Greyzamic Phaeozems and Folic Fluvisols with oil (Solovatovsky oil field, Perm region) added in amounts of 1, 2, 3 and 5g oil/kg of soil on the organisms was studied in a model laboratory experiment. Oil addition showed phytotoxic effects on root length in Triticum aestivum L., Lepidium sativum L., Picea obovata Ledeb. and Pinus sylvestris L. in all soils. However, oil contamination of Calcaric Leptosols and Greyzamic Phaeozems led to growth stimulation in Picea obovata seedlings. A remarkable shift in the diversity and number of colony-forming units of heterotrophic and oil-oxidizing bacteria was detected in all soil types. The maximum decrease in biodiversity (45%) was noted for heterotrophic bacteria in Luvic Phaeozems. Aqueous extracts from all oil-contaminated soils had a toxic effect on Chlorella vulgaris Beijer, causing an increase in biomass by more than 30%, but did not show acute toxicity on Daphnia magna Straus. Oil addition in the range of 1-3g oil/kg soil posed no environmental risk to human health. However, oil addition at 5g oil/kg of soil led to an increase in the level of carcinogenic risk to children to the threshold values of acceptable risk and ranged from 0.95 × 10-4 for Greyzamic Phaeozems and Folic Fluvisols to 1.098 × 10-4 for Luvic Phaeozems. Our results suggest that the reaction of test organisms to oil pollution depends on the soil type, and their complex application makes it possible to identify the most sensitive factor and assess the dangerous level of pollution.

Influence of oil pollution on the surface of the microbial community and catalase activity of sod - podzolic soil

The article provides data on the influence of different levels of oil pollution on the structure of the microbial community and the activity of catalase in sod-podzolic soil during the cultivation of barley and wheat. It also presents data on the effect of biopreparations based on oil-oxidizing bacteria on the total number of microorganisms, microscopic fungi, actinomycetes and catalase activity. Based on the analysis of the microflora of oil-contaminated soddy-podzolic soil, it was found that oil pollution affects the total number of microorganisms, the qualitative and quantitative composition of micromycetes. and actinomycetes. It was also found that small concentrations of oil stimulate the number of microbiota and catalase activity. The introduction of biological products based on oil-oxidizing bacteria has a beneficial effect on the indicators of the general biological activity of the soil. It is noted that the selection of a phytomeliorant is of great importance in the reclamation of non-contaminated soil.

Reduction of the effect of toxic substances on the human body in the production of oil-oxidizing bacteria

One of the most effective methods for cleaning soil and water bodies from oil and oil products is the biotechnological method using oil-degrading bacteria. However, their production is a rather complicated process, during which many unfavorable factors act on the human body. The paper considers the process of cleaning an industrial fermenter with a CIP (Cleaning in Place) contactless cleaning system. An automatic metering valve for supplying direct steam during sterilization has been proposed. This reduces the human factor and the risk of workers being poisoned by surfactant species used to clean the fermenter.

Эффективная очистка донных отложений водоемов от нефтяного загрязнения с помощью геоконтейнерной технологии

Статья посвящена актуальной в настоящее время теме очистки донных отложений водоемов от их загрязнения углеводородами, произошедшего в результате аварийных утечек нефти и нефтепродуктов или в процессе эксплуатации нефтяных скважин. Одним из перспективных способов их очистки является недавно появившаяся в России геоконтейнерная технология, суть которой состоит в изъятии донных отложений для их последующего обезвоживания в геоконтенерах и доведения качества почвы до установленных нормативов. Геоконтенеры изготовлены из специальной ткани, способной пропускать воду и растворенные в ней вещества, но хорошо задерживать твердые частицы различных размеров. Приведены результаты исследования применения геоконтейнерной технологии для ремедиации донных отложений трех озер, сильно загрязненных нефтью, в Западной Сибири, Ханты-Мансийском автономном округе - Югре (Нижневартовск) в 2013 году. Сорок четыре геотубы были заполнены пульпой донных отложений трех озер, размещены на платформе нефтяных скважин и оставлены на два года в естественных климатических условиях. После этого случайным образом были отобраны пробы из 14 геотуб и проведена оценка изменений физико-химических свойств, биологической активности и фитотоксичности проб по сравнению с исходными загрязненными пробами. Показано, что за два года произошло значительное снижение концентрации общих нефтяных углеводородов на 81-98%. Очищенные почвы из геоконтейнеров содержали большое количество нефтеокисляющих бактерий, гетеротрофных и автотрофных микроорганизмов и обладали высокой биологической активностью при отсутствии острой фитотоксичности. Данная технология отличается высокой эффективностью, простотой и экологичностью и может конкурировать с другими способами очистки, используемыми для данных целей. The article is devoted to the currently relevant issue of cleaning up bottom sediments of water bodies polluted with hydrocarbons as a result of accidental leakage of oil and oil products or oil spills during routine operations of oil production. One of the promising ways of their recovery is the geotube technology recently introduced in Russia, which involves removing bottom sediments from the site of pollution with their subsequent dehydration in geocontainers and cleaning up the soil quality to the established standards. Geocontainers are made of a special fabric, capable for transmitting water with the dissolved substances with safely retaining solid particles of various sizes. The results of a case study of using of geocontainer technology for remediation of bottom sediments of three lakes heavily contaminated with oil in Western Siberia, Khanty-Mansi Autonomous Okrug - Ugra (Nizhnevartovsk) are presented. In 2013, forty-four geotubes were filled up with pulp from the bottom sediments of three lakes, then placed on an oil well platform and left for two years. After that, samples from 14 geotubes were randomly selected and tested for changes in physicochemical properties, biological activity, and phytotoxicity compared to the initial oil-polluted samples. A significant decrease was found in the concentration of total petroleum hydrocarbons, i.e. by 81-98%. Purified soils from geotubes contained a noticeable amount of oil-oxidizing bacteria, heterotrophic and autotrophic microorganisms, and exhibited high biological activity without acute phytotoxicity. The proposed technology is characterized by high efficiency, simplicity and environmental friendliness and can compete with the known cleaning procedures used for the same purposes.

Исследования селекции микроорганизмов для разложения нефтепродуктов c повышенной нитрогеназной активностью в лабораторном биореакторе

The article presents the results of studies on decomposition of petroleum products, on the example of diesel fuel, the investigation having been carried out in a bioreactor with loading of immobilized microorganisms specially selected and adapted to the destruction of hydrocarbons. In the course of the investigation, 25 micro-organism culture strains were isolated from crude oil by selection, the strains had different destructive activity relative to hydrocarbons of the paraffin fraction of diesel fuel and nitrogen-fixing ability. Further, selection was carried out along with oxidation of hydrocarbons and according to the ability of microorganisms to nitrogen fixation. Such microorganisms during oxidation of hydrocarbons will allow reducing the content of biogens in purified water. Part of the microorganisms was identified and the nitrogenase activity of pseudomonades was investigated. When growing on diesel hydrocarbons in a bioreactor, nitrogen assimilation is most active in Rhodococcus erythopoltis R-2 culture and equals 10.52 nmol C2H4/mg protein per hour. The maximum nitrogenase activity has the association of bioreactor destructive cultures obtained by the authors, which, when growing on diesel oil products is 23.7 nmol C2H4/mg protein per hour, which is 2.3 times higher than the nitrogen-fixing capacity of Rhodococcus erythropoltis R-2. There was studied the rate of hydrocarbon degradation, оn the seventh day of cultivation, the degradation of paraffinic hydrocarbons in nitrogen-free media is 68%, whereas in the presence of ammonium nitrogen it reached - 87 %. These investigations have determined the ability of isolated cultures of oil-oxidizing bacteria to use hydrocarbons under atmospheric nitrogen assimilation conditions.

Состав донных отложений приливо-отливной акватории (юго-западный район Татарского пролива)

Data on the carbon hydrates content and composition is given: aliphatic hydrocarbons and aromatic hydrocarbons in comparison with total organic matter, phyto/pigments and quantity of heterotrophic and oil-oxidizing bacteria in bottom sediments of the Toki River tide estuary (the Tatar Strait). It has been stated that substance/structural composition of the sedimentation material in the Toki River estuary is determined by two matter flows of opposite direction: terrigenous runoff with river waters (wood and grass remains, fresh water phyto- and bacteria-plankton, anthropogenous pollutants including aliphatic hydrocarbons and aromatic hydrocarbons) and materials of marine origin including mineral components (fine-dispersed sand fractions), died-off macrovegetations, sea grass phyto- and bacteria- plankton. Phyto-and bacteria-benthos communities well-adopted to variable conditions of salinity are developing in bottom sediments. High ability of the benthos microbe community to hydrocarbons utilization has been revealed. At the same time intermediate products of organic matter destruction (spirits and ethers) are found in the estuary bottom sediments micro/aerophilic conditions. Over the period from 2009 to 2016 a considerable increase of toxic aromatic hydrocarbons content in the Toki River internal estuary has been registered – a probable source of them is a solid waste dump located on the river catchment. According to group composition of н-alkanes molecular spectra, natural sources contribute the most in formation of the current bio/geo/chemical background of the smaller estuary.

Химико-микробиологическая характеристика вод и донных отложений Керченского пролива и прилегающих акваторий

Представлены результаты исследований уровня загрязнения нефтяными углеводородами и хлороформ-экстрагируемыми веществами донных отложений и морской воды районов черноморского предпроливья и Азовского моря (весна, осень 2016 г.). Выполнено сравнение уровней загрязнения морской среды с результатами предыдущих исследований (2007–2010 гг.). Приведены количественные характеристики гетеротрофной и нефтеокисляющей микробиоты в обозначенных районах. Установлено, что концентрация нефтяных углеводородов в поверхностном слое воды района азовского предпроливья в целом не превышала значения ПДК (0,05 мг·л-1). Исключение составили результаты, полученные осенью 2016 г. Численность гетеротрофных бактерий изменялась в поверхностном слое воды Азовского моря в пределах 104–105 кл.·мл-1, нефтеокисляющие бактерии были выделены в единичных количествах. В акватории причерноморского района пролива число гетеротрофных бактерий составило 106 , численность нефтеокисляющих бактерий не превысила 10 кл.·мл-1. При сравнении с данными прошлых лет отмечено увеличение содержания хлороформкстрагируемых веществ и нефтяных углеводородов в донных отложениях. Общий уровень загрязнения при этом не превышал средних величин, определённых для данного региона. Численность гетеротрофных бактерий в донных отложениях в приазовской акватории варьировала от 2,5·104 до 4,5·104 кл.·г-1, а нефтеокисляющих бактерий — от 2,5·10 до 4,5·102 кл.·г-1. В донных отложениях черноморского предпроливья число гетеротрофов составляло 4,5·103 кл.·г-1, нефтеокисляющих бактерий — 10 кл.·г-1.

Oil-Oxidizing Bacteria of Zaporozhskoye Reservoir

The study of oil-oxidizing bacteria number and activity has been carried out for the first time in contaminated with oil products and relatively clean areas of Zaporozhskoye reservoir in spring 2014. The research showed high potential oxidative capacity (POC) of water microflora that probably corresponds to the level of water pollution with oil products. During spring season the spatial distribution of oil bacteria as well as dependence on sampling time and water temperature were studied. Analysis of spatial distribution of oil-oxidizing bacteria numbers allowed to perform ranking of the sites with increasing of bacteria numbers in direction from the site "Near Kodaki water draw-off" to "Monastyrskiy island". Distribution of oil-oxidizing bacteria observed during the period of study reflects pollution and self-cleaning state of the sites. Using correlation analysis conclusion about connection of oil-oxidizing bacteria with diatoms "bloom" in spring has been made that shows importance of "bloom" for the realization of bacteria role in reservoir self-cleaning. The results are important for understanding the mechanisms of maintaining Zaporozhskoye reservoir ecosystem stability as well as for forecasting of pollution and self-purification processes and in general for the development and implementation of natural and artificial ecosystems sustainable development.

Oil-Oxidizing Bacteria of Zaporozhskoye Reservoir

The study of oil-oxidizing bacteria number and activity has been carried out for the first time in contaminated with oil products and relatively clean areas of Zaporozhskoye reservoir in spring 2014. The research showed high potential oxidative capacity (POC) of water microflora that probably corresponds to the level of water pollution with oil products. During spring season the spatial distribution of oil bacteria as well as dependence on sampling time and water temperature were studied. Analysis of spatial distribution of oil-oxidizing bacteria numbers allowed to perform ranking of the sites with increasing of bacteria numbers in direction from the site "Near Kodaki water draw-off" to "Monastyrskiy island". Distribution of oil-oxidizing bacteria observed during the period of study reflects pollution and self-cleaning state of the sites. Using correlation analysis conclusion about connection of oil-oxidizing bacteria with diatoms "bloom" in spring has been made that shows importance of "bloom" for the realization of bacteria role in reservoir self-cleaning. The results are important for understanding the mechanisms of maintaining Zaporozhskoye reservoir ecosystem stability as well as for forecasting of pollution and self-purification processes and in general for the development and implementation of natural and artificial ecosystems sustainable development.

Evaluation of biocidal properties of vegetable oil-based corrosion inhibitors using bioluminescent enzymatic method

The biocidal activity of carbonic-acid corrosion inhibitors (CIs) based on fatty acids from different vegetable oils against bacterial cells that catalyze biocorrosion processes was investigated using the bioluminescent method for determining the intracellular ATP concentration. It was shown that all obtained CIs exhibited biocidal activity with the amide complexes of fatty acids being the most effective. Their activity was 4.6-fold higher than the activity of nonamide complexes. The minimal inhibitory concentration that causes the death of all bacterial groups was established for the majority of the CIs to be in the range 100–170 mg/mL, and the best biocidal properties against the oil-oxidizing bacteria of the Pseudomonas genus were observed for the CI prepared from the corn oil (27 mg/mL).

Microbial communities of the discharge zone of oil- and gas-bearing fluids in low-mineral Lake Baikal

At the site of natural ingress of oil microbial diversity in the Central Baikal bottom sediments differing in the chemical composition of pore waters was studied by molecular biological techniques. The sediments saturated with oil and methane were found to contain members of 10 bacterial and 2 archaeal phyla. The oxidized sediment layer contained methanotrophic bacteria belonging to the Alphaproteobacteria, which had a specific structure of the pmoA gene and clustered together with uncultured methanotrophs from cold ecosystems. The upper sediment layer contained also oil-oxidizing bacteria and the alkB genes most colsely related to those of Rhodococcus. The microbial community of reduced sediments exhibited lower diversity and was represented mostly by the organisms involved in hydrocarbon biodegradation.

Rhodococcus lactonase with organophosphate hydrolase (OPH) activity and His6-tagged OPH with lactonase activity: evolutionary proximity of the enzymes and new possibilities in their application

Decontamination of soils with complex pollution using natural strains of microorganisms is a matter of great importance. Here we report that oil-oxidizing bacteria Rhodococcus erythropolis AC-1514D and Rhodococcus ruber AC-1513D can degrade various organophosphorous pesticides (OP). Cell-mediated degradation of five different OP is apparently associated with the presence of N-acylhomoserine lactonase, which is pronouncedly similar (46-50 %) to the well-known enzyme organophosphate hydrolase (OPH), a hydrolysis catalyst for a wide variety of organophosphorous compounds. Additionally, we demonstrated the high lactonase activity of hexahistidine-tagged organophosphate hydrolase (His6-OPH) with respect to various N-acylhomoserine lactones, and we determined the catalytic constants of His6-OPH towards these compounds. These experimental data and theoretical analysis confirmed the hypothesis about the evolutionary proximity of OPH and lactonases. Using Rhodococcus cells, we carried out effective simultaneous biodegradation of pesticide paraoxon (88 mg/kg) and oil hydrocarbon hexadecane (6.3 g/kg) in the soil. Furthermore, the discovered high lactonase activity of His6-OPH offers new possibilities for developing an efficient strategy of combating resistant populations of Gram-negative bacterial cells.

Soils and waste water purification from oil products using combined methods under the North conditions

Oil and gas production and transportation in Russia is increasingly moving to the north regions. Such regions are characterized by relatively low self-purification capacity of the natural environments from the contaminants due to slow character of the energy exchange and mass transfer processes. Off-shore field development in the Barents Sea and oil product transportation can result in contamination, as confirmed by the national and international practice of the developed oil and gas regions. The research aims at development of the soil bioremediation methods and industrial waste water purification contaminated by oil products in the north-western region of Russia. The dynamics of oil products carry-over have been investigated under the field model experiments in podzolic soils: gas condensate, diesel fuel and mazut from oil and the plants were selected for phyto-remediation of contaminated soils under high north latitudes. It is shown that soil purification from light hydrocarbons takes place during one vegetation period. In three months of the vegetation period the gas condensate was completely removed from the soil, diesel fuel – almost completely (more than 90%). Residual amounts of heavy hydrocarbons were traced, even 1.5 later. The following plants that were highly resistant to the oil product contamination were recommended for bioremediation: Phalaroides arundinacea, Festuca pratensis, Phleum pratense, Leymus arenarius. There has been developed and patented the combined method of treatment of waste water contaminated with hydrocarbons based on inorganic coagulants and local oil-oxidizing bacteria.

Polyethylene Destruction by the Mixed Culture of Microorganisms

Polyethylene film destruction by mixed culture of microorganisms was studied. The initial culture was adapted for growth on the media with ion exchange resin. During cultivation of the microorganisms on the mineral media with a polyethylene as the only source of carbon and energy the increase of film roughness and decrease of amorphous fraction and crystal size was detected. Using atomic-force microscopy and scanning electron microscopy it was found the film reduce to the crystals of micron size and unilamellar crystal fragments. The film relief change and crystal size decrease was detected after contact with oil-oxidizing bacteria and after composting with plant residuals with redworm Eisenia foetida.

Modeling of the marine environmental pollution by petroleum hydrocarbons and their biotransformation in Tatar Strait waters

A hydroecological model is used for simultaneous studying water pollution processes by petroleum hydrocarbons and their decay under the oceanographic conditions of Tatar Strait. The model calculations were based on long-term averaged observational data on interannual variations of water temperature, light intensity, and transparency. Some oceanographic characteristics of the strait were reconstructed with the help of GIS “Sakhalin Shelf.” The strait’s water area was divided into three regions, and water exchange between them and the neighboring regions of the Sea of Japan was estimated by a hydrodynamic model. The results of the study made it possible to assess interannual variations in the concentrations and inner fluxes of petroleum hydrocarbons, oil-oxidizing bacteria biomasses, and the characteristics of their oxidation activity.