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1.
Bioremediation is an effective measure in dealing with such contamination, particularly those from petroleum hydrocarbon sources. The effect of soil amendments on diesel fuel degradation in soil was studied. Diesel fuel was introduced into the soil at the concentration of 5 % (w/w) and mixed with three different organic wastes tea leaf, soy cake, and potato skin, for a period of 3 months. Within 84 days, 35 % oil loss was recorded in the unamended polluted soil while 88, 81 and 75 % oil loss were recorded in the soil amended with soy cake, potato skin and tea leaf, respectively. Diesel fuel utilizing bacteria counts were significantly high in all organic wastes amended treatments, ranging from 111 × 106 to 152 × 106 colony forming unit/gram of soil, as compared to the unamended control soil which gave 31 × 106 CFU/g. The diesel fuel utilizing bacteria isolated from the oil-contaminated soil belongs to Bacillus licheniformis, Ochrobactrum tritici and Staphylococcus sp. Oil-polluted soil amended with soy cake recorded the highest oil biodegradation with a net loss of 53 %, as compared to the other treatments. Dehydrogenase enzyme activity, which was assessed by 2,3,5-triphenyltetrazolium chloride technique, correlated significantly with the total petroleum hydrocarbons degradation and accumulation of CO2. First-order kinetic model revealed that soy cake was the best of the three organic wastes used, with biodegradation rate constant of 0.148 day?1 and half life of 4.68 days. The results showed there is potential for soy cake, potato skin and tea leaf to enhance biodegradation of diesel in oil-contaminated soil.  相似文献   

2.
The detection of microorganisms with potential for biodeterioration and biodegradation in petroleum fields is of great relevance, since these organisms may be related to a decrease in petroleum quality in the reservoirs or damage in the production facilities. In this sense, petroleum formation water and oil samples were collected from the Campos Basin, Brazil, with the aim of isolating microorganisms and evaluating their ability to degrade distinct classes of hydrocarbon biomarkers (9,10-dihydrophenanthrene, phytane, nonadecanoic acid and 5α-cholestane). Twenty eight bacterial isolates were recovered and identified by sequencing their 16S rRNA genes. Biodegradation assays revealed that bacterial metabolism of hydrocarbons occurred through reactions based on oxidation, carbon–carbon bond cleavage and generation of new bonds or by the physical incorporation of hydrocarbons into microbial cell walls. Based on the biodegradation results, selective PCR-based systems were developed for direct detection in petroleum samples of bacterial groups of interest, namely Bacillus spp., Micrococcus spp., Achromobacter xylosoxidans, Dietzia spp. and Bacillus pumilus. Primer sets targeting 16S rRNA genes were designed and their specificity was confirmed in silico (i.e. computational analysis) and in PCR reactions using DNA from reference strains as positive and negative controls. Total DNA from oil was purified and the amplification tests revealed the presence of the target bacteria in the samples, unraveling a significant potential for petroleum deterioration in the reservoirs sampled, once proper conditions are present for hydrocarbon degradation. The application of molecular methods for rapid detection of specific microorganisms in environmental samples would be valuable as a supporting tool for the evaluation of oil quality in production reservoirs.  相似文献   

3.
Microbially produced lipopeptide have been isolated and studied for microbial enhanced oil recovery. About 60 gram positive bacteria isolated from soil contaminated with crude oil, near the crude oil storage tank in Tehran Refinery, Tehran, Iran. However, most of these studies have produced lipopeptide by one of the pure-culture microbes isolated in a laboratory. Among the isolates, heamolytic tests revealed two biosurfactant producers. The isolated strains were designated as C2, E1. By using morphological, biochemical and molecular biology tests (16 SrRNA), the strains identified as Bacillus licheniformis and Bacillus subtitlis, respectively. Emulsification activity and measurement of surface tension indicated that, the isolates were high producers of biosurfactant. The product of C2 and E1 is mainly lipopeptide. This product reduce surface tension from 65 to 30 mN/m. Emulsified activity of crude oil was 92% for C2 and 90 % in case of E1. This is the first report of indigenous Bacillus licheniformis and Bacillus subtilis from a soil contaminated with oil in an Iranian refinery with ability to produce biosurfactant.  相似文献   

4.
从青藏高原班戈桥地区土壤中分离到一株能利用原油为碳源生长的细菌(BGQ-6). 通过16S rRNA基因序列比对及Biolog GEN Ⅲ鉴定板确定该菌株为Rhodococcus qingshengii. 将生长至对数期的菌株接入MM培养基, 10 ℃、150 rpm条件下培养15 d后, 通过GC法检测到该菌对原油的总降解率为74.14%, 且对直链烷烃、支链烷烃、环烷烃和芳香烃等60种烃类有较高的降解率. 通过特异性基因扩增检测到该菌株基因组中具有4个alkB和1个almA两种烷烃羟化酶基因.  相似文献   

5.
Three microbial consortia were isolated from three polluted soils located at an oil refinery and acclimated to grow on diesel fuel as the sole carbon source. Batch experiments were then conducted with the three consortia to study the kinetics of diesel biodegradation. The effects of temperature (25, 30 and 35?°C) and diesel concentration (0.5, 1 and 3?%) on the biodegradation of diesel were analysed. Several species were identified in the acclimated microbial consortia, and some of them appeared in more than one consortium. Thermal inhibition was observed at 35?°C. In the rest of experiments, over 80?% of the substrate was degraded after 40?h of treatment. These results proved the good feasibility of using the polluted sites as sources of mixed consortia for hydrocarbon degradation. However, diesel degradation efficiencies and rates were very similar, suggesting that the acclimation process produced mixed consortia with very similar characteristics; in this context, origin of the soil sample was not a decisive factor. A simple Monod-type kinetic model was used to simulate the biodegradation process, and accurate results were obtained. The ?? max values were between 0.17 and 0.34?h?1. The results of this study revealed that the consortia can function at high concentrations of hydrocarbons without any sign of growth inhibition, which is important for the design of bioreactors for wastewater treatment with high concentrations of fuel.  相似文献   

6.
The bacteria and plants were associated to remove diesel oil pollutants from soil.Three efficiently degrading bacteria(named strains Q10,Q14 and Q18,respectively) were isolated.Two plants(alfalfa and Indian mustard) were selected to form the association.Biodegradation of diesel oil pollutants in soil was accelerated by bacteria-plants association.The main results are summarized as follows.The plants-bacteria association was more effective in biodegradation of diesel oil pollutants in soil than in respective experiments carried out with plants or bacteria alone.Strain Q18-Indian mustard association resulted in the maximum diesel oil reduction(69.18%).The activities of catalase and polyphenol oxidase in soil were enhanced and microbial populations in soil,especially in rhizosphere,were also stimulated in the treatment of bacteria-plant association.Overall,the soil conditions might be improved by alfalfa or Indian mustard to benefit the growth of bacteria,which resulted in degradation of diesel oil pollutants more effective by the bacteria-plant association.The bacteria-plants association may be a better approach to the removal of diesel oil pollutants from soil.  相似文献   

7.
The development of the bioaugmentation during the phytoremediation of contaminated water with diesel in pilot horizontal subsurface flow constructed wetlands was investigated for 63 days. The objective of this study was to examine the enrichment of rhizobacteria in a pilot-scale system for efficient treatment of total petroleum hydrocarbon (TPH) effluent. A consortium of three rhizobacteria strains (Bacillus aquimaris, Bacillus anthracis and Bacillus cereus), which were able to utilize hydrocarbon compounds as sole carbon sources, was injected into the constructed wetlands (batchwise operation) planted with Scirpus grossus. The TPH removals from water, without or with the addition of rhizobacteria, were found to be 72 and 84%, while from sand was found to be 59 and 77%, for each treatment, respectively. These results showed that the rhizobacteria strains could enhance S. grossus growth by decreasing diesel stress and protecting S. grossus against diesel, with 12 and 18% additional TPH removal from water and sand, respectively. Our results demonstrate that S. grossus is potential to improve the phytoremediation of hydrocarbon contaminants through inoculation with effective rhizobacterial strains.  相似文献   

8.
Poly(3-hydroxyalkanoates) (PHAs) are the bioplastics that are stored in many genera of bacteria as carbon and energy storage polyester granules. PHAs have established themselves as strong competitors to conventional plastics. This study reports the isolation of PHA-accumulating bacteria from local environment and their PHA characterization. Two potential strains identified as Pseudomonas aeruginosa strain IFS (Accession no. JQ041638) and P. aeruginosa strain 30N (Accession no. JQ041639) based on 16S rRNA gene sequence identity were cultivated under nitrogen limited conditions to study their PHA biosynthesis capabilities. The strain IFS and strain 30N produced 1.36 and 1.40 gl?1 dry biomass with percentage PHA contents of 44.85 and 45.74%, respectively, when grown on glucose as carbon source. The PHA was identified as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by fourier transform infrared spectroscopy (FTIR) and gas chromatography coupled with mass spectrometry (GC–MS). The PHA synthase genes of these strains were isolated, sequenced and analyzed using bioinformatic tools that showed they belonging to type 2 PHA synthases and presented their evolutionary relationships with PHA synthases of other Pseudomonas species. The experimental results of this study highlight the importance of these strains for future use of bacterial biopolymer production growing on simple and inexpensive carbon sugars.  相似文献   

9.
The aim of this study was to look for high efficient bioflocculant-producing microorganisms. Among 36 bacterial colonies isolated from a crude petroleum oil sample, three of them as Bacillus subtilis and Pseudomonas spp. exhibited flocculation activity exceeding 90 % after 3 days of cultivation. They were identified by 16 S rDNA sequence analysis as Bacillus subtilis and Pseudomonas sp. Spectroscopic analysis of the polymers by nuclear magnetic resonance and fourier-transform infrared revealed that the polymers were glycoproteins. These polymers were soluble in water and insoluble in any organic solvents tested. The effects of bioflocculant dosage, temperature and pH on the flocculation activity were evaluated. The maximum bioflocculation activities were observed at an optimum bioflocculant dosage of 3.5 mg/L (strains Bacillus subtilis and Pseudomonas) and 5.0 mg/L (strain CPO14), respectively. In addition, these biopolymers were able to flocculate kaolin suspension (5 g/L) over a wide range of pH (pH 3–9) and temperature (5–50 °C) tested in the presence of CaCl2. The highest flocculation activities of strains CPO8, CPO13 and CPO14 were 96.03 %, 92.17 % and 97.59 %, respectively in the early stationary phase (at 24 h), while the cell production reached its maximum in the stationary phase (at 72 h). Their efficient flocculation capabilities suggest potential applications in industries.  相似文献   

10.
Recently, decreasing of fossil fuel reserves and their negative effect on environment have increased the interest in alternative energy sources. One of the alternative energy sources is vegetable oils. In this study, blends of 50 % opium poppy oil — 50 % diesel fuel mixture are tested as alternative fuel on a single cylinder, 4-stroke, air cooled, pre-combustion chamber diesel engine at different speeds and its effects on engine performance and emissions are investigated. When compared to the diesel fuel as average, engine torque and power decrease at 4 % and 5.73 %, respectively. Specific fuel consumption increases by using of 50% opium poppy oil — 50 % diesel fuel mixture. When compared to the diesel fuel as average, carbon monoxide and nitrogen oxides emissions of 50 % opium poppy oil — 50 % diesel fuel mixture decrease to 15.5 % and 5.9 %, respectively. Diesel fuel-opium poppy oil mixture has been found notably successful and environment friendly as an alternative fuel for diesel engines.  相似文献   

11.
石油脱硫微生物菌株的筛选及鉴定的研究   总被引：2，自引：0，他引：2  
从胜利油田和冀东油田采集被石油污染的土壤样品,经富集技术培养后,从中分离出21株脱硫菌,再从中筛选出一高效脱硫菌株TV9704。这一菌株不能以正十二烷、正十六烷、液体石蜡、萘和柴油为碳源和能源生长,因此不会明显地损失石油的燃烧值;但它能利用噻吩或二苯并噻吩(DBT)作为唯一硫源来生长。本实验中噻吩和DBT的浓度使用UV分光光度计测定。菌株TV9704在噻吩起始浓度为63.2mmol/L的培养基中分别培养48h和144h后,它对噻吩的降解率分别为39.0%、63.8%;在DBT起始浓度为2.7mmol/L的培养基中培养72h,DBT降解了1.46mmol/L。选择醋酸钠和甘油为碳源时,乙醇能显著提高TV9704对DBT的降解率。菌株TV9704经中国工业微生物菌种保藏管理中心(CICC)鉴定为芽孢杆菌(Bacillussp),革兰氏阳性,专性好氧,在营养肉汁平板上形成橙黄色的圆形菌落。对菌株TV9704所作16SrDNA基因序列测定和分析显示,它与最相似种Bacillus aquimaris,Bacillus marisflavi的同源性分别为99.2%和98.2%,但它们之间的细胞形态特征及生理生化特性相差较大,因此无法鉴定到种。菌株TV9704可能是一个新种。  相似文献   

12.
Petroleum and fuel oil are complex mixtures of recalcitrant hydrocarbons. The biodegradation of these hydrocarbons needs the action of a vast variety of enzymatic capacities. A microbial consortium offers the capability to degrade complex substrates through the assembly of different biochemical reactions, providing a metabolic versatility superior to axenic cultures. In this work, the microbial population dynamics, taxonomy, and the catabolic capacity of a stabilized consortium exposed to fuel and crude oil was analyzed through metagenomics. The stabilized consortium degraded 59% of crude oil components after 8 days, and 34% of fuel oil components after 130 days. Population dynamics analysis indicates that in fuel oil the biodiversity richness was higher; however, denaturing gradient gel electrophoresis similarity dendrogram shows significant changes in the microbial population during crude oil degradation. Taxonomy studies indicate a great genera divergence; only eight microbial genera were common in both samples. In crude oil, the Limnobacter sp. was the most abundant specie (15.6%), while Sphingomonas wittichii (7.9%) and Novosphingobium aromaticivorans (7.6%) were abundant in fuel oil. These microorganisms have been reported to participate in the degradation of aliphatic and aromatic hydrocarbons. Functional analysis suggests that fuel and crude oil components changed the interactions between the consortium members affecting the collective metabolic functionality.  相似文献   

13.
Isolation of hydrocarbonoclastic bacteria from bilge oil contaminated water   总被引：1，自引：1，他引：0  
Two bacterial strains, i.e. Pseudomonas mendocina and Ochrobactrum sp. were isolated from bilge oil contaminated water of Mormugao harbour, Goa, India and grown in a culture medium with hexadecane as the sole carbon source. Pseudomonas mendocina was used in further studies as it was the dominant strain. This strain effectively degraded tetradecane, hexadecane and octadecane leaving a residual concentration of about 73 %, 54 % and 40 % respectively in 120 h. Sequence analysis of the dominant bands from the denaturing gradient gel electrophoresis profiles revealed the differences between the genera of bilge oil contaminated sea water and its enrichment culture on hexadecane indicating a shift in community structure based on the type of substrate available. Pseudomonas mendocina amplified for the following catabolic genes namely C23O, nid and ndo. Based on the catabolic gene study the potential of the bacterial strain isolated, i.e. Pseudomonas mendocina seems to be interesting as it will be able to degrade polyaromatic hydrocarbons as well. Physicochemical properties of Pseudomonas mendocina indicates production of exopolysaccharides based on the value of its isoelectric point.  相似文献   

14.
The correlation between oxides of nitrogen emission and in-cylinder temperature of diesel engine fueled with various alternative fuels has been investigated in this research paper. Experimentations were performed in engine without any modifications using pure high-speed diesel fuel, used cooking oil biodiesel (UCO20), animal fat residue biodiesel (AFR20) and camphor oil (CMR20) at 20% volume concentration of biodiesel each. From combustion analysis, the heat release rate and peak cylinder pressure of biodiesel blends were about 13.487% lower and 4.819% higher than those of diesel fuel on an average, respectively. Longer combustion duration has been observed for all biodiesel blends at all load conditions. Oxides of nitrogen emission level show 16.405, 10.352 and 7.524% increment for UCO20, AFR20 and CMR20, respectively. Noteworthy NO x reduction of about 43.8% was recorded for diesel blended with camphor oil when compared to other biodiesel blends. The relationship between in-cylinder temperature and NO x emission concentration was premeditated through thermal imager. The result depicted that the increase in NO x concentration depends on augmented in-cylinder temperature for all test fuels.  相似文献   

15.
Soil pollution by crude oil is a challenging environmental issue for oil producing countries. Several methods have been developed for remediation of the contaminated soil including washing with different detergents. In this work, we applied UTCHEM simulator model to the sand columns polluted by 10000 and 30000 ppm of crude oil which was treated with 0.05, 0.1 and 0.2 wt% of a biological detergent, saponin. The results showed a good agreement between simulated and pilot study. The maximum remediation was 61% with a pH of 9 when we utilized 0.2 wt% saponin for the column contaminated with 30000 ppm of crude oil. 47% remediation was achieved with a pH of 9 when 0.1wt% of detergent was applied to the same column. Sensitivity analysis indicated an increase in remediation by increasing the pH with the optimum pH of 11. The best possible concentrations of surfactant solutions were 0.1 and 0.2 wt% for 10000 and 30000 ppm pollution, respectively, resulting in crude oil removal efficiencies of 69% and 72%, respectively. Simulation results also indicated that an increase in the permeability of the sand columns would also result in an increased remediation.  相似文献   

16.
Waste engine oil causes a vital environmental pollution when it spill during change and transportation and products of waste engine oil causes lethal effects to the living systems. Thus, abiotic and biotic approaches are being extensively used for removal of waste engine oil pollution. Therefore in present study, waste engine oil degradation was accomplished by a new bacterial culture, isolated from the soil by an enrichment technique. Morphological, biochemical and gene sequence analysis revealed that isolate was Bacillus cereus. Subsequently, biodegradation potential of B. cereus for waste engine oil was studied. Experimental variables, such as pH, substrate concentration, inoculum size, temperature and time on the biodegradation, were checked in mineral salt medium. The biodegradation efficiency of B. cereus was determined by gravimetry, UV–visible spectrophotometry and gas chromatography. In addition, waste engine oil was also characterized by GC–MS and FTIR for its major constituents, which showed total 38 components in waste engine oil, including hopanes, benzopyrene, long-chain aliphatic hydrocarbons, dibenzothiophenes, biphenyl and their derivatives. Results of successive biodegradation indicated that B. cereus was capable to degrade 1% of waste engine oil with 98.6% degradation potential at pH 7 within 20 days. Hence, B. cereus presents an innovative tool for removing the engine oil from the contaminated area.  相似文献   

17.
青藏高原土壤中链霉菌的分离鉴定及其抗菌活性研究   总被引：1，自引：0，他引：1  
对从青藏高原采集的土壤样品中的链霉菌进行了分离鉴定,并对其抗菌活性进行了研究. 结果表明：11份土样中分离出菌落形态特征明显不同的链霉菌相似菌株151株,对其中43株进行了16S rDNA测序分析,41株菌株与已知链霉菌的相似性在99%以上,确定为链霉菌属（Streptomyces）菌种,而菌株WDL-DM-5和TTH-DM-1与已知链霉菌的序列相似性分别为90.76%和95%. 抗菌试验表明,68株链霉菌对革兰氏阳性菌和阴性菌有抗性,其中41株菌对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌都有明显拮抗性,表明青藏高原土壤中存在强拮抗性的链霉菌.  相似文献   

18.
Performance and pollutants features of Jatropha–Mineral Turpentine blends along with diesel have been examined in a single-cylinder compression ignition engine. Vegetable oils have higher viscosities than diesel fuel, and it greatly disturbs the performance, durability, burning and discharge features of the compression ignition engine. The tests were performed with different blend combinations of Jatropha–Mineral Turpentine oil as fuel. The experimental outcome indicates that brake thermal efficiency of the blend of 80% Jatropha Biodiesel and 20% of Mineral Turpentine is nearby to diesel fuel at 75% load. Carbon monoxides, hydrocarbons and emission were reduced to the considerable amount, whereas the oxides of nitrogen increase with increase in part load and reduced with 75% and full load operations. The specific fuel consumption of Jatropha–Mineral Turpentine blends found to be slightly upper than diesel fuel. The heat release rate and cylinder pressure of Jatropha–Mineral Turpentine blends were closer to diesel fuel. The test results recommend that Jatropha–Mineral Turpentine blends might stay a decent auxiliary to diesel fuel in the near upcoming and it can be concluded that Jatropha–Mineral Turpentine oil blends could be utilized in a conventional compression ignition engine with no alteration.  相似文献   

19.
A potassium solubilizing bacterial strain designated EGT, which is tolerant of high temperature, was isolated from an earthworm’s gut to obtain a bacterium that can weather potassium-bearing rock effectively through solid-state fermentation. Molecular phylogeny and 16S rRNA gene sequence analysis demonstrated the bacterial strain was a member of the Streptomyces genus. To assess its potential to release potassium from silicate minerals, this strain was used to degrade potassium-bearing rock powder by solid-state fermentation. After fermentation, the amount of water-soluble Al, Fe and K of the substrate with active inoculum was higher than those of the control, which had autoclaved inoculum, and those of the fresh substrate. The result indicated that the strain had the ability to weather potassium-bearing rock and could be used as an inoculum in the production of potassium bio-fertilizer, due to its potassium release activity from rock and tolerance to high temperature.  相似文献   

20.
Two native ionizing radiation-resistant bacteria were isolated and identified from a soil sample collected from extreme conditions of the Lout desert in Iran. The hottest land surface temperature has been recorded in the Lout desert from 2004 to 2009. Also, it is categorized as a hyper arid place. Both ionizing radiation and desiccation may cause damage on genome. Soil sample was irradiated in order to eliminate sensitive bacteria then cultured in one-tenth-strength tryptic soy broth medium. Bacterial suspension used for radiation treatment. Morphological and physiological characterization and phylogenetic studies based on 16S rRNA gene sequence were used for identification. The cells were rod shape, non-motile, non-spore forming and gram positive. The 16S rRNA gene sequence showed 99.5 % of similarity to Deinococcus ficus. Phylogenetic dendrogram demonstrated that the isolates branched with D. xibeiensis, D. ficus and D. mumbaiensis. Both isolates were resistant to >15 kGy of gamma radiation and >600 J m2 of UV radiation. This is the first report on radiation resistant bacteria belonging to genus Deinococcus isolated from the Lout desert of Iran.  相似文献   

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