جستجوی مقالات مرتبط با کلیدواژه « crude oil » در نشریات گروه « زیست شناسی »

Today, oil pollution has evolved into a global environmental concern. One of the methods for mitigating this pollution is the use of biological approaches, especially microorganisms, known for their cost-effectiveness and environmental friendliness, rendering them particularly popular among various methods. This study aimed to explore the potential growth of oil-degrading bacteria in oil-contaminated soils, as well as their ability to remove crude oil. Based on bacterial growth rates in the presence of crude oil and hydrocarbon degradation capabilities, two strains, Sludge C and SHA, were selected from among 13 isolates obtained from oil-contaminated soil near the Shiraz refinery. Subsequently, they were assessed for oil degradation using spectrophotometry and gas chromatography methods. Results indicated that Sludge C and SHA possess oil consumption abilities of 64.4% and 84.2%, respectively, within 7 days. Gas chromatography analysis highlighted SHA's remarkable capability in removing short, medium, and long-chain hydrocarbons. Molecular identification confirmed the affiliation of this strain with the genus and species Acinetobacter junii. With its high oil consumption potential, this strain holds promise for efficient utilization in environmental remediation and industry.

Today, one of the main environmental problems is hydrocarbon pollution due to the activities of oil and petrochemical industries. Accidental oil spills occur in the environment during the exploration, production, transportation, and storage of petroleum products. Technologies commonly used for soil remediation are expensive and can lead to the incomplete degradation of pollutants. Biodegradation is a cost-effective technology for the recovery of oil-contaminated areas.

This study was conducted to isolate crude oil degrading bacteria, soil, and sludge from seven oil-contaminated areas in Masjed Soleyman. To determine the frequency of heterotrophic and degrading bacteria, the bacteria were counted by the serial dilution and MPN methods. Twenty-four strains were isolated by the culture enrichment method in Bushnell-Haas broth medium containing 0.5% crude oil. Then, based on warm staining and colonial characteristics, oil spreading test, cell surface hydrophobicity, and the emulsion activity of the strains were examined for initial screening. Finally, the top 10 strains were screened by spectrophotometric and gravimetric methods with a concentration of 0.5% crude oil. Also, Gas Chromatography (GC) was performed on the superior strain.

The identified strains belonged to the genus Rhodococcus jostii strain D3 and Arthrobacter citreus strain E3. The top two strains were studied to investigate the effects of different concentrations of crude oil, nutrient effects, time effects, and mixed culture. The highest oil expansion was related to F3 strain and the highest emulsion activity rate was related to E3 strain. D3 strain with 41% degradation at the concentration of 4.5 and E3 strain with 73.5% degradation at the concentration of 1.5 showed the best results in response to different crude oil concentrations. The results of gas chromatography analysis confirmed that strain D3 can degrade 95 percent of crude oil at the concentration of 0.5%.

The identified strains have a great potential in removing hydrocarbon pollution and can be used at the field level to reduce and eliminate oil pollution in the contaminated areas in the future.

Pollution of the environment with petroleum and its derivatives is a serious threat to human health and the environment, so treatment of these substances is of great importance. The bioremediation process is defined as the use of microorganisms to remove many industrial effluents, including petroleum products. The aim of this research is isolation and characterization of crude oil degrading bacteria from some industrial sewage at Shiraz province

This study was performed to isolate crude oil degrading bacteria from some industrial areas of Shiraz. To investigate the effect of crude oil on the frequency and variety of microbial populations of Soil and water sampling, identification and counting of crude-oil degrading bacteria and heterotrophic bacteria were performed by CFU and MPN methods. Preliminary identification of the strains was carried out based on gram staining, colony shape and microscopic characteristics. Then properties such as oil-spreading,emulsifying activity and growth and degradation rate of these bacteria were investigated.

After screening, it was found that 20 strains were capable of growing and decomposing crude oil The highest oil-spreading,bacterial adhesion to hydrocarbon, emulsifying activity were related to PE3, SN1, DS1, 23%, 16% and 22%, respectively. Using these results seven suitable strains were selected and crude oil removal rates were determined by spectrophotometric and gravimetric methods for each strain. One strain with the highest rate of crude oil degradation was identified molecularly. This strain belonged to the genus Cellulosimicrobium cellulans. The highest percentage of degradation by this strain was in the concentration of 1.5% at 67%. Percentage of oil degradation of this strain by analyzing the effects of mixture culture, excess carbon source, excess nitrogen source, excess carbon and nitrogen source, time was 75%, 71%, 100%, 81%, 100%, respectively.

The results of this study showed that the use of these microorganisms by creating optimal conditions can be an important step in the removal and control of oil pollution.

On 4 July 2019, Gibraltar seized oil tanker Grace 1. The Gibraltar`s Chief Minister stated that considering the sanctions under European Council Decisions 255 and 36 including prohibition of the sale, supply and export of equipment, goods and technology which might be used for internal repression of the people of Syria and also the restriction on the purchase, import and transfer of the crude oil from Syria which was imposed for the purpose of the reduction of the financial ability of the Syrian government, the main question of the paper is whether the measures taken by the Gibraltar are legally justifiable.

Today, crude oil is one of the main sources of energy. The combustion of sulfur-containing compounds in fossil fuels leads to the production of sulfur oxides that has adverse effects to human health and the environment. At the moment, the current method for removal of sulfur is Hydrodesulfurization. The aim of this study was to investigate the effect of magnetic nanoparticles and modified carbon nanotubes as nano-adsorbent on improving the biodesulfurization activity of microorganisms (Rhodococcus erythropolis IGTS8). In the current experimental study, the nanoparticles were synthesized by chemical co-precipitation and the carbon nanotubes were initially carboxylated. Multi-layer carbon nanotubes were mixed with 95% sulfuric acid and 52% nitric acid (volume ratio 1:3) and, then, modified by polyethylene glycol. In order to characterize nanoparticles and carbon nanotubes, scanning transmission electron microscopy (STEM), X-ray diffraction, magnetic surveys, analysis of arch Raman, and fourier-transform infrared spectroscopy (FTIR) were conducted. The size of nanoparticles was estimated to be 7-8nm and modified carbon nanotubes showed the highest solubility as well as stability in deionized water for two weeks. The growth of microorganisms in the presence of magnetic nanoparticles and carbon nanotubes compared to their absence increased by 40% and 8%, respectively. Moreover the desulfurization activity of microorganisms in the presence of magnetic nanoparticles and carbon nanotubes showed a significant increase compared to their absence. Nanoparticles with adsorption of sulfur compounds increase their availability for microorganisms.

In this study, fungal strains with crude oil biodegradation activity were screened from Shazand oil refinery (Arak). Twelve fungal strains were isolated in PDA medium. TPH assay in the presence of 1% of crude oil showed that the ADH-02 was the most capable strain of oil degradation with an efficiency of 75%. FTIR analysis was revealed that 91% of aliphatic hydrocarbons were degraded by ADH-02. This strain proved to belong to Gliomastix genius with a similarity of 99%. Polycyclic aromatic hydrocarbons degradation analysis with HPLC demonstrated that this strain is capable of removing 67% of anthracene in 14 days. The results showed that Gliomastix sp. was a potent fungal strain in bioremediation of crude oil and polycyclic aromatic hydrocarbon.

Caspian Kutum is a native and economic species of the Caspian Sea in the southern parts and due to the oil extraction, is at risk to pollution via different ways. Among the different types of pollutants, petroleum (hydrocarbons) is one of the most important pollutants in the aquatic environment. The present study aimed to find the acute effects of water-soluble fraction of crude oil (WSF) on some physiological parameters of Rutilus frisii at different time. Two treatments included two concentrations of WSF in three replicates and 120 hours was considered in the experiment. Eighty fish (average weight 0.77 ± 0.06 g) was introduced in aquarium with the dimensions of 50×30×70cm. In each aquarium, 70 L WSF solution was added with above mentioned concentrations. Lactate dehydrogenase activity and whole-body cortisol in 15 fish were measured for 0, 6, 12, 24, 48, 72, 96, 120 h. Analysis of variance showed significant differences in the interaction between cortisol concentration and time and also time was observed in 95% significance level (P0.05) but difference in time was seen in 95% level (P

Petroleum pollution is the most important environmental pollution due to increasing usage of oil and oil dependent products. Soil microorganisms are the most important organisms that are affected at the early stage of pollution and also are effective for removing and degradation of the oil. In this research, fungi in agricultural soils were adapted for growing in petroleum-polluted media. Trichoderma fungal species are saprophytes that are living in agricultural soils. The aim of this research was to elucidate the effect of petroleum pollution on the growth of soil fugal species including Trichoderma species. Ten species of Trichoderma were selected and adapted for growing in the presence of oil. The fungi were cultured in the PDA containing of 1% crude oil and then were transferred to the media containing 2, 4 and 6% crude oil, step by step. Growth ability of the fungi was studied in the media containing different crude oil after 11 days based on colony diameter. Results showed that the all fungi were able to adapt to petroleum pollution and are growing in the presence of crude oil but it was less than control media. The highest colony diameter was observed in T. citrinoviride and the lowest one was in T. koningiopsi. These results indicated that the growth ability of T. citrinoviride in the petroleum-polluted media is more than other fungal species and so is more suitable for bioremediation of petroleum-polluted soils.

Bioremediation is the promising technology for the treatment of the contaminated sites since it is cost-effective and will lead to complete mineralization. This study was aimed to isolation and phylogenetic identification of indigenous oil-degrading bacteria from soil of Karoon area in Ahvaz.
The crude oil contaminated soil of Karoon area in Ahvaz was sampled accidentally and under sterile condition. The amount of absorbable phosphorus was determined using Olson method and also, carbon, hydrogen and nitrogen by CHN meter device. Mineral salt medium containing 2% crude oil was used for isolation of oil eating bacteria. Following sieving the soil samples, the total carbon content of the soils were analysed by gas chromatography. Biochemical tests and PCR method were used to identify the dominant bacteria.
In this study, 44 bacterial strains were isolated, among them 20 isolates in the first and one in the second screening methods were selected, which was nominated as S31.This strain belonged to Bacillus licheniformis. The growth of the selected isolate in the media with 2% crude oil was better than the standard strain and remediated 84% of the crude oil in 30 days incubation time at about 30o C.
The selected Bacillus could use 2% of crude oil as source of carbon and energy and we suggest further studies on this bacterium in bacterial consortia.

Petroleum pollution is the most important soil pollution. Bioremediation is an effective and usable technology for remediation of polluted soils. Some microorganisms have bioremediation potency for petroleum compounds. In this research Tabriz city was selected as a cold area of Iran for studying of native bacteria with biodegradation potency of crude oil. Soil samples were collected from polluted soils of Tabriz refinery and their bacteria were accommodated to crude oil. The bacterial strains exited in the samples were isolated، grouped and determined. The growth ability and petroleum removal efficiency were evaluated for the each bacterium at the different crude oil concentrations during a month. In this research، seven bacterial species were found that are well accommodated to crude oil. The highest petroleum removal efficiency (98%) was determined for Pseudomonas aerogenesis at concentration of 0. 5%. Biological removing of crude oil with high efficiency is possible by soil bacterial flora، as an environmental friendly method، even for soil cleaning of the industrial areas in cold temperature regions.

Many Species of fungi with ability to metabolize of petroleum hydrocarbons are known so far. These fungi are resistant in oil contaminated sites.This investigation aims at studying fungal population diversity in oil contaminated soils of Khuzestan province and identifying fungal flora in these regions. Crude oil contaminated soil samples were collected from different regions of Khuzestan province. For isolation and enumeration of total heterotrophic fungi, Potato Dextrose Agar medium supplemented with streptomycine was used. The isolated fungi were identified via morphological studies, staining by lactophenol cotton blue, observation with a light microscope and comparing with descriptive and canonizative refereces. Total fungal counts ranged from 0.41 × 102 to 3333.33 × 102 CFU/g. Isolated fungi belong to Aspergillus, Penicillium, Fusarium, Candida, Rhodotorula, Aureobasidium, Mucor, Rhizopus and Acremonium. Most dominant genera were Aspergillus and Penicillium. Discussion and Studies on isolation of fungi in oil containing environments showed that, abundance and fungal diversity in different stations significantly were different. The increase in the number of fungi in crude oil soils showes the probability of degradation and consumption of oil contaminated by fungi. Diversity and distribution of soil microbial population are determined by a number of environmental factors such as pH, electrical conductivity and soil organic matter.

Oil pollutions are one of the major problems threatening environment. Biodegradation using hydrocarbon-degrading indigenous bacteria is considered as a convenient method both economically and environmentally. The genus Alcanivorax is known as a petroleum hydrocarbon degrader in petroleum-contaminated marine environments. The purpose of this study was to evaluate the capacity of Alcanivorax dieselolei, isolated from the coastal sediments of Persian Gulf for crude oil biodegradation.

In this applied-fundamental study, first oil degrading bacteria were isolated from the coastal sediments of Persian Gulf and were enriched in media. The isolated bacterium was identified using molecular identification based on 16S rRNA sequence. The oil degrading ability of the isolates was assessed using various concentrations of crude oil.

Based on molecular approaches the isolated bacterium was identified as Alcanivorax dieselolei. This bacterium was able to disintegrate oil droplets stably in less than one minute. Results showed that the biodegradation rates at 1, 2.5 and 5% concentrations of crude oil were 68.37, 67.97 and 13.2% respectively.

Since Alcanivorax genus is an indigenous bacterium in hydrocarbon polluted marine environments and its capability in biodegradation of crude oil has been proved, using this bacterium to remove oil pollutants is certainly possible.

Desulfurization of thiophenic compounds is one of the important issues in refineries and environmental pollutions control. A bacterium was isolated from MTBE enriched soil was able to desulfurize of the thiophene. It was identified as Pseudomonas stutzeri based on phylogenetic analysis of 16S rRNA gene sequence. Desulfurization reactions from thiophene as the model of thiophenic compounds in aqueous phase by resting cells of this strain carried out and the concentration of thiophene was determined by UV-visible spectrophotometer in 230 nm wavelength. The results showed that the reduction of thiophene was 95% (from 12. 4 mM to 0. 3 mM) after 15 hours. Gas chromatography analysis showed the same results of thiophene desulfurization. Furthermore، The desulfurization activity of resting cells in a biphasic system containing crude oil by determination of released sulfate content turbidimetrically with BaCl2 was investigated.

The oil spillage has always been a source of contamination in the soil affecting the environment، the plant and animal life. The source of the contamination is usually due to faulty extraction of the oil from the earth، refining، processing and finally the transportation. The spillage of the crude oil can penetrate through the soil and get to the underground water and the farming lands and by doing so، damage the animals grass land and humans farming products. Lentil is a widely used crop in human''s diet and so it makes it important to be investigated. In this study، the effect of the contaminated soil on the growth and germination of the lentil and the activity of alkaline phosphatase has been investigated. The results showed that the 5% concentration of oil in the soil delayed and decreased the number of germination and the biomass of the shoots and the roots، also decreasing the normal size of the leaves. Therefore 5% concentration of crude oil in the soil showed it is a suitable dose to study the effect of contamination on the enzyme. The results showed that the activity of the enzyme in the roots of the control was significantly different compared with that of the contaminated ones. Measurement of the enzyme kinetics for the determination of the Vmax and Km also showed a significant difference، suggesting that there may be an alkaline phasphatase isozyme presence in the roots، which is responsible for this difference observed between the contaminated and the control samples.

Surface discharge of dens jet as a common way for disposal of produced waste water in coastal areas is strongly influenced by the hydraulical and physical fissures of discharge stream and ambient water. In the current study, considering different mechanisms of flow in surface discharge of negative buoyant jets, dominated regimes are studied. Using Length Scale (L.S.) method and utilizing an experimental set up which are merely designed for this studies, different flow regimes were experimentally simulated and its behavior were investigated. As a result of this study, the observed criteria for free jet regime, shoreline attached jet regime and intruding upstream plume in the case of surface discharge of dens jets were précised and their ranges of diversity in the form of dimensionless diagram were developed. The axis’s of this diagram are a couple of dimensionless parameters that formed by the flow variables where each shows classification criteria in the boundaries of diagram. Finally, extracted criteria as a separator of these regimes were used to develop a tree-like classification scheme in surface discharge of dens jets. In this method, through identifying the range of flow variables in occurrences of each regime and sub regimes, coming prediction of flow characteristics by empirical equations will easily be possible.

Oil spills can result in the deposition of large quantities of petroleum hydrocarbons intointertidal and shallow waters seriously impacting bivalve populations. Petroleum hydrocarbonsare enriched in polycyclic aromatic hydrocarbons (PAHs) and PAH analogs many ofwhich may have potential chromosomal aberration. The micronuclei (MN) test is useful for assessing chromosomal aberration and DNA damage and has been used to a limited degree with aquatic organisms, but mostly with studies in vitro. This study carried out with the MN test to assess the DNA damaging potential of crude oil the complex mixtures of petroleum hydrocarbons for bivalves.Micronucleus test, one of the most popular and promisingtest ofenvironmental genotoxicity, has served as an index ofcytogenetic damagefor over 30 years. Micronuclei (MN) are produced from chromosome fragmentsor whole chromosomes that lag at cell division due to lack ofcentromere, damage in centromere or defect in cytokinesis. Intissues with actively dividing cells, micronuclei records reflectaction of clastogenic or aneugenic compoundsThis study presents the data on rate of MN numbers with use of micronuclei (MN) test in gill cells offreshwater bivalve molluscs (Anodonta cygnea) exposed to crude oil. Bivalves were exposed for ten days to 0.25, 0.5 and 1.0 ppm of crude oil. For the micronuclei (MN) test Two branches of mussel gills were placed in a big drop of 3:1 ethanol acetic acid (or methanol acetic acid) solution separately on two clean microscopic slides and gently nipped with tweezers for 2–3 minutes (until cells spread within a drop). Then the cell suspension was softly smeared on the whole surface (except label place) of both slides. Dried slides were fixed in methanol for 10 min. and stained with 5% Giemsa solution in phosphate buffer pH = 6.8. The stained slides were analyzed under the light microscope at a final magnification of 1000×. a statically significant increase in level of micronuclei (MN) was found with 0.25, 0.5 and 1.0 ppm of crude oil. The rate of MN frequency was measured 1.6, 2.6 and 2 MN/1000 gill cells, respectively. The frequency of micronuclei was varied from 0 to 2.6 ‰ (MN/1000 cells).This study has demonstrated a potential for DNA damage in bivalvesexposedto crude oil as well as potential for interspecies sensitivity.