Biodegradation Of Oil Research Articles

Enhancement of repeated inoculation strategy with a domesticated bacterial consortium on the biodegradation of high-level crude oil in soil

Repeated inoculation of hydrocarbon degrading microbes should be powerful to improve the survival of inoculant, which is vital to achieve efficient remediation of petroleum contaminated soil. This paper aims to study the repeated inoculation (with different inoculum size and time interval) enhanced bioremediation of high-level petroleum contaminated soil with a domesticated bacterial consortium. The copy number of bacterium and alkB gene, soil enzyme activities and microbial community structure during the remediation were systematically analyzed to preliminarily reveal the mechanism of repeated inoculation affecting remediation for the first time. The results revealed that repeated inoculation remarkably improved the total petroleum hydrocarbon (TPH) removal in soil (86.5 % in HC120) compared with a single inoculation (68.9 % in HA120). The TPH removal of repeated inoculation with high inoculum size (HC) on the 60th day was close to that of once inoculation (HA) on the 120th day, suggesting that repeated inoculation led to faster degradation. Interestingly, the effect of inoculation with low dose and more times (LC120, 78.5 %) was equal to that with high dose and less times (HB120, 78.0 %), even much better than that with high dose and once inoculation (HA120). Treatment HC had a significant impact on the soil bacterial diversity and community structure, and the dominant species in the inoculants, such as Stenotrophomonas and Pseudomonas, which was low abundance in the blank group (CK), still maintained high abundance during the remediation process. The soil catalase activities and the number of alkB gene were the highest in HC. Correlation analysis implied that repeated inoculation of hydrocarbon degrading bacteria did improve the survival of inoculant, soil enzyme activities and maintain the number of degrading bacteria, thus promoting the TPH removal. These findings will facilitate the practical application of bioremediation technology to contaminated environment, which has important environmental and economic benefits.

Novel oil-associated bacteria in Arctic seawater exposed to different nutrient biostimulation regimes.

The Arctic Ocean is an oligotrophic ecosystem facing escalating threats of oil spills as ship traffic increases owing to climate change-induced sea ice retreat. Biostimulation is an oil spill mitigation strategy that involves introducing bioavailable nutrients to enhance crude oil biodegradation by endemic oil-degrading microbes. For bioremediation to offer a viable response for future oil spill mitigation in extreme Arctic conditions, a better understanding of the effects of nutrient addition on Arctic marine microorganisms is needed. Controlled experiments tracking microbial populations revealed a significant decline in community diversity along with changes in microbial community composition. Notably, differential abundance analysis highlighted the significant enrichment of the unexpected genera Lacinutrix, Halarcobacter and Candidatus Pseudothioglobus. These groups are not normally associated with hydrocarbon biodegradation, despite closer inspection of genomes from closely related isolates confirming the potential for hydrocarbon metabolism. Co-occurrence analysis further revealed significant associations between these genera and well-known hydrocarbon-degrading bacteria, suggesting potential synergistic interactions during oil biodegradation. While these findings broaden our understanding of how biostimulation promotes enrichment of endemic hydrocarbon-degrading genera, further research is needed to fully assess the suitability of nutrient addition as a stand-alone oil spill mitigation strategy in this sensitive and remote polar marine ecosystem.

Biodegradation and high-value utilization of waste cooking oil: Strategies and mechanisms for producing lipopeptide biosurfactants using Bacillus subtilis YZQ-2

This study explored the strategies and mechanisms of Bacillus subtilis YZQ-2 in producing lipopeptide biosurfactants using waste cooking oil (WCO) as a raw material. The optimal conditions achieved a WCO utilization rate of 75.88% and a biosurfactant yield of 0.30g/L at pH 6.0, 30°C, with 20g/L WCO and 5g/L yeast extract. GC-MS analysis of degradation products at different intervals elucidated the mechanism of WCO degradation. After 72hours of fermentation, a reduction in linoleic and palmitic acid levels indicated the completion of lipid hydrolysis and the continuation of β-oxidation. The biosurfactants, identified as lipopeptides (surfactin and fengycin), exhibited stability in alkaline environments (pH 7.0-11.0) and high-salt concentration (5-45g/L). Genomic and transcriptomic analyses of Bacillus subtilis YZQ-2 revealed genes associated with biosurfactant production, which were upregulated in the presence of WCO. The differential expression values (log2 fold change) were SrfAA 3.30, SrfAB 3.31, SrfAC 3.63, FenA 2.42, FenB 2.55, FenC 1.99, FenD 2.03 and FenE 2.29, respectively. The proposed biosynthesis pathway of lipopeptides begins with the hydrolysis of WCO by lipase into glycerol and fatty acids. The glycerol is then transformed into pyruvate through glycolysis, entering the Tricarboxylic Acid cycle. Additionally, pyruvate contributes to synthesizing amino acids and branched-chain fatty acids, which serve as precursors for lipopeptide synthesis. These findings underscore the potential of WCO as a sustainable feedstock for biosurfactant production.

Experimental investigation on performance of bubble-bursting atomization methods for minimum quantity lubrication in face milling tool steel

The metal cutting industry faces challenges in machining hard materials due to high forces and temperatures. This paper introduces bubble-bursting atomization minimum quantity lubrication (BBA-MQL), a novel MQL technique that generates fine biodegradable oil mists for cooling and lubrication. Although the initial results of BBA-MQL are promising, there has not been a comprehensive investigation into its use in machining hard materials, specifically tool steels. Therefore, this study focused on the applicability of BBA-MQL in face milling of AISI P20 + Ni tool steel in comparison with dry cutting and conventional MQL using commercial and vegetable oil. The machining tests were performed at three cutting speeds (50, 80, and 110 m/min), fixed cutting depth (0.2 mm), and feed rate (0.15 mm/tooth). The performance is evaluated by measuring the cutting force, surface quality, cutting temperature, and tool wear. It was found that BBA-MQL decreased cutting force and surface roughness considerably, with the average reductions being 23.2 % and 49.8 % compared with the conventional minimum quantity lubrication. The highest cutting speed of 110 m/min was preferred for achieving the lowest roughness value and cutting force when milling tool steel P20 + Ni. Furthermore, BBA-MQL with castor oil proved more effective compared to conventional MQL in reducing cutting force, showing improved surface finish, reduced cutting temperature, and delayed tool wear.

Biodegradation of Spent Automobile Engine Oil in Soil Microcosms Amended with Coconut Shell

Food insecurity and low yield have resulted from the detrimental effects of petroleum hydrocarbon pollution on agricultural soils over time. This study was carried out to determine the bioremediation efficacy of coconut shell on microbiological composition and total petroleum hydrocarbon degradation in spent engine oil polluted soil. Top soil (0-15 cm depth) samples were randomly collected from areas with history of spent engine oil pollution within Anyigba, Kogi State, Nigeria. One kilogram of the polluted-soil was measured into each of nine plastic containers. Coconut shell collected from the Prince Abubakar Audu University, Anyigba, was standardly prepared and mixed with the soil at the rate of 0, 50 and 100 g kg-1 soil in triplicate. The experiment used a completely randomized design. Soil samples were taken from each container at 0 and 28 days for hydrocarbon utilizing bacteria and total petroleum hydrocarbon determination using standard methods. Data obtained from the experiment were subjected to descriptive and inferential statistics. The species identified were Enterobacter sp and Escherichia coli, with Enterobacter sp being the most predominant isolate. The total petroleum hydrocarbon (mgkg-1) of the soil on day 0 was 59.78 ± 1.85. After the amendments (at control, 50 and 100 g kg-1), the total petroleum hydrocarbon (mgkg-1) values were 44.92 ±2.26, 34.82 ± 1.78 and 31.49 ± 0.87 at 28 days respectively. Coconut shell and the high level carbon utilizing bacteria, Enterobacter sp, significantly enhanced the biodegradation process as an impressive 47.32% remediation efficiency was achieved 28 days after amendment in soil treated with 100g of coconut shell. It is recommended that a biostimulation strategy that uses coconut shell and Enterobacter sp be employed in the remediation of spent engine oil and petroleum hydrocarbon polluted soils.

Use of pseudomonas fluorecens isolated from the Serra de Ouro Branco State Park/Minas Gerais - Brazil in the biodegradation of residual automotive lubricating oils

About 2% of the oil consumed worldwide is related to the production of automotive and industrial lubricating oils. The pollution derived from these oils in aquatic and terrestrial environments is responsible for several ecological and social problems due to their toxic, mutagenic, and carcinogenic properties. Thus, studies related to bioremediation are of importance, and the use of biological treatments, such as biodegradation, is a viable and effective alternative for the treatment of these compounds. The present study aimed to evaluate the biodegradation performance of residual automotive lubricating oils using the lipases Pseudomonas fluorecens obtained in bioprospecting carried out in the Serra do Ouro Branco State Park, Minas Gerais. Through the colorimetric method using the redox indicator 2.6-dichlorophenol-indophenol (DCPIP), the biodegradability of residual oils was monitored. The results obtained demonstrated the potential of the selected bacteria, since they degraded approximately 61.74 to 83.8 % of the waste studied.

Effect of Nitrogen-15, Phosphorus-15, and Potassium-15 Fertilizer on Indigenous Microorganisms Involved in Biodegradation of Crude Oil Contaminated Soil Collected from Shawguwolo Jeddo Metropolis, Okpe L.G.A, Delta State, Nigeria

The increasing occurrence of oil pollution presents a significant environmental challenge, necessitating effective remediation strategies. Hence, the objective of this paper was to evaluate the effect of Nitrogen-15, Phosphorus-15, and Potassium-15 fertilizer on indigenous microorganisms involved in biodegradation of crude oil contaminated soil collected from Shawguwolo Jeddo Metropolis, Okpe L. G. A, Delta State, Nigeria using appropriate standard methods. It was observed that the hydrocarbon reduced from 5315.80 to 2276.57 within four weeks. The highest rate was observed in sample C, which showed a 95.7% reduction in the hydrocarbon contamination. Sample C also showed a 34% increase in the hydrocarbon utilizing bacteria present in the soil. Bioremediation leverages microbial activity to degrade pollutants, offering a cost-effective approach compared to other technologies, as it speeds up the process of degrading hydrocarbon by increasing the growth rate of hydrocarbon utilizing bacteria.

Experimental Study on Tribological, Rheological and Bio-degradability Characteristics of Canola Oil with TiO2 Nanoparticles as Bio-nanolubricants

In response to growing environmental concerns about the adverse effects of conventional lubricants, there has been a surge in the demand for eco-friendly alternatives. Biodegradable lubricants, crafted from renewable sources, represent a sustainable solution to address these environmental apprehensions. This research describes the tribological, rheological properties and biodegradability of rapeseed oil with 0.25 to 1.25 weight percent TiO2 nanoparticles as additives. The lubricant samples were prepared using a magnetic stirrer and an ultrasonic device. Friction and wear properties such as coefficient of friction and wear scar diameter were determined using a four-ball tester. In comparison with SAE20W40, samples 1 (0.25 weight percentage of TiO2) and sample 2 (0.5 weight percentage of TiO2) shown remarkably improved tribological performance, with 73.32% and 66.76% decreases in coefficient of friction (COF), respectively. Shear stress, shear rate and dynamic viscosity are analyzed using a rheometer. The acquired results are juxtaposed with both pure canola oil and various mineral oils for comparison. The nano-lubricant synthesized in this study emerges as a viable alternative to SAE10, DXT3 (steering fluid), and SAE20W50 grade oils, demonstrating lower friction and a reduced wear scar diameter. Biodegradability tests were performed on all generated samples using the Biochemical Oxygen Demand (BOD) apparatus, and all samples exhibited a BOD to Chemical Oxygen Demand (COD) ratio better than 0.5, indicating biocompatibility. The findings of the research investigation indicate that the combination of canola oil with TiO2 blends holds significant promise as an alternative to conventional synthetic lubricant oils.

The Implications of Seeping Hydrocarbon Gases in the Gunsan Basin, Central Yellow Sea, off the Southwest of Korea

A detailed analysis of high-resolution (3.5 kHz) chirp seismic profiles acquired in the Gunsan Basin of the central Yellow Sea revealed that hydrocarbon gases are actively seeping via the formation of many plumes. The uppermost sedimentary layer was acoustically confirmed to be fully or partially charged with gases. Somewhat favored by the low-tide period, episodic gas seepage is mainly associated with the underlying fault systems of Cretaceous-Cenozoic sedimentary strata in the southwestern part of the basin. Catastrophic gas expulsion seems to have formed a crater at the sidewall of a sedimentary ridge and two diapirs. Here, methane is poorly concentrated but rich in the heavy carbon isotope (δ13C, −52.6‰ to −44.7‰ The Vienna Peedee Belemnite [VPDB]), indicating that methane formed mainly through biodegradation of heavy oils at depth remains in the shallow sediments following its expulsion. Episodic rapid upward advection of porewater is also manifest by unmixed heavy methane trapped in the upper part of the primary biogenic methane (δ13C, about −90‰ VPDB)-filled sediment core. These findings imply that the Gunsan Basin fulfills the requirements for possible generation and preservation of oil and gas, like the petroliferous basins of eastern China and the Yellow Sea.

Molecular identification of rhamnolipids produced by Pseudomonas oryzihabitans during biodegradation of crude oil.

The ability to produce biosurfactants plays a meaningful role in the bioavailability of crude oil hydrocarbons and the bioremediation efficiency of crude oil-degrading bacteria. This study aimed to characterize the produced biosurfactants by Pseudomonas oryzihabitans during the biodegradation of crude oil hydrocarbons. The biosurfactants were isolated and then characterized by Fourier transform infrared (FTIR), liquid chromatography-mass-spectrometry (LC-MS), and nuclear magnetic resonance spectroscopy (NMR) analyses. The FTIR results revealed the existence of hydroxyl, carboxyl, and methoxyl groups in the isolated biosurfactants. Also, the LC-MS analysis demonstrated a main di-rhamnolipid (l-rhamnopyranosyll-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoate, Rha-Rha-C10-C10) along with a mono-rhamnolipid (l-rhamnopyranosyl-b-hydroxydecanoylb-hydroxydecanoate, Rha-C10-C10). In agreement with these findings, the NMR analysis confirmed the aromatic, carboxylic, methyl, sulfate moieties, and hexose sugar in the biosurfactants. The emulsion capacity of the biosurfactants decreased the surface tension of the aqueous system from 73.4 mN m-1 to around 33 mN m-1 at 200 mg L-1 as the critical micelle concentration. The emulsification capacity of the biosurfactants in the formation of a stable microemulsion for the diesel-water system at a wide range of pH (2-12), temperature (0-80°C), and salinity (2-20 g L-1 of NaCl) showed their potential use in oil recovery and bioremediation through the use of microbial enhancement. This work showed the ability of Pseudomonas oryzihabitans NC392 cells to produce rhamnolipid molecules during the biodegradation process of crude oil hydrocarbons. These biosurfactants have potential in bioremediation studies as eco-friendly and biodegradable products, and their stability makes them optimal for areas with extreme conditions.

Conditional Optimization of Single Cell Protein Production from Crude Oil by <i>Pseudomonas aeruginosa</i>

The study was carried out to investigate the possible biodegradation of crude oil as a carbon by the bacterium <i>Pseudomonas aeruginosa</i> isolated from marine environment (Ras El-Menkar- Benghazi- Libya) using basal yeast extract protease peptone-3 (BYP) enriched medium. The isolated bacterium was identified and characterized according to its cultural condition and microbial biochemical properties. Different experiments were developed throughout this study to stimulate bacterial growth and production of single cell protein (SCP). The results show that the optimal concentration of crude oil as a carbon source for the highest bacterial growth (1.14g/l), and production of SCP (0.65g/l; 57.02% of the biomass dry weight) was 1%. This was required to utilize up to 50.6% of oil as a carbon source. As to the nitrogen source, the optimal concentration of ammonium chloride was 0.1%, in which the bacterial growth and SCP production increased to 1.23 g/l and 0.67 g/l respectively. The stimulating effects of organic and inorganic factors on the bacterial growth and SCP production was also tested. Addition of inorganic nutrients such as potassium phosphate (0.05%), magnesium sulphate (0.01%), and organic nutrient in the form of yeast extract (0.1%) to the fermentation medium slightly promoted the bacterial growth which reflected positively on SCP production and the percentage of the consumed crude oil, (>57%) at final pH value of 8.0. The obtained results indicated that the isolated<i> Pseudomonas aeruginosa</i> posses the ability to utilize the crude oil and use it as a carbon for bacterial growth and production of SCP.

Compositional change of bacterial communities in oil-polluted seawater amid varying degrees of nanoplankton bacterivory

Petroleum hydrocarbons are being released into the marine environment continuously. They will undergo weathering and may eventually be biodegraded by bacteria and other microbes. While nanoplankton (2–20 μm) are the major consumers of marine bacteria, their effect on the process of biodegradation of oil hydrocarbons is still debated. A 14-day microcosm experiment was conducted to investigate the effects of crude oil hydrocarbons on nanoplankton bacterivory and bacterial community in coastal waters. The coefficients of population growth (0.56–1.80 d−1 for all treatments considered) and grazing mortality (0.38–1.65 d−1 for all treatment considered) of bacteria estimated with the dilution method did not differ among the treatments of control (Ctrl), low dose chemically dispersed oil (LDOil, 2 μL L−1 of crude oil), and high dose chemically dispersed oil (HDOil, 8 μL L−1 of crude oil). Bacterial abundance ranged between 0.21–0.86 × 106 cells mL−1 on average for all treatments. The lack of drastic increases in the cell density of bacterial cells in the oil-loaded treatments was observed throughout the experiment period. Sequencing analysis of the 16S rRNA gene revealed the progressive changes in the community compositions of bacteria in all treatments. The relatively high abundance of oil-degrading bacteria, including Cycloclasticus and Alcanivorax on Days 3–14 of the experiment reflected the presence of biodegradation of oil in the LDOil and HDOil treatments. Throughout the 14 days, the community composition of bacteria in the LDOil and HDOil treatments became more similar and they both differed from that in the Ctrl treatment. This study concluded that, in oil-polluted seawater, the changes in the bacterial community composition were mainly resulting from the addition of chemically dispersed crude oil.

Biodegradation of Crude Oil by Nitrate-Reducing, Sulfate-Reducing, and Methanogenic Microbial Communities under High-Pressure Conditions.

Carbon capture, utilization, and storage (CCUS) is an important component in many national net-zero strategies, and ensuring that CO2 can be safely and economically stored in geological systems is critical. Recent discoveries have shown that microbial processes (e.g., methanogenesis) can modify fluid composition and fluid dynamics within the storage reservoir. Oil reservoirs are under high pressure, but the influence of pressure on the petroleum microbial community has been previously overlooked. To better understand microbial community dynamics in deep oil reservoirs, we designed an experiment to examine the effect of high pressure (12 megapascals [MPa], 60 °C) on nitrate-reducing, sulfate-reducing, and methanogenic enrichment cultures. Cultures were exposed to these conditions for 90 d and compared with a control exposed to atmospheric pressure (0.1 MPa, 60 °C). The degradation characteristic oil compounds were confirmed by thin-layer analysis of oil SARA (saturates, aromatics, resins, and asphaltenes) family component rods. We found that the asphaltene component in crude oil was biodegraded under high pressure, but the concentration of asphaltenes increased under atmospheric pressure. Gas chromatography analyses of saturates showed that short-chain saturates (C8-C12) were biodegraded under high and atmospheric pressure, especially in the methanogenic enrichment culture under high pressure (the ratio of change was -81%), resulting in an increased relative abundance of medium- and long-chain saturates. In the nitrate-reducing and sulfate-reducing enrichment cultures, long-chain saturates (C22-C32) were biodegraded in cultures exposed to high-pressure and anaerobic conditions, with a ratio of change of -8.0% and -2.3%, respectively. However, the relative proportion of long-chain saturates (C22-C32) increased under atmospheric pressure. Gas Chromatography Mass Spectrometry analyses of aromatics showed that several naphthalene series compounds (naphthalene, C1-naphthalene, and C2-naphthalene) were biodegraded in the sulfate-reducing enrichment under both atmospheric pressure and high pressure. Our study has discerned the linkages between the biodegradation characteristics of crude oil and pressures, which is important for the future application of bioenergy with CCUS (bio-CCUS).

Response Characteristics of the Community Structure and Metabolic Genes of Oil-Recovery Bacteria after Targeted Activation of Petroleum Hydrocarbon-Degrading Bacteria in Low-Permeability Oil Reservoirs.

The microbial enhanced oil recovery (MEOR) process has been identified as a promising alternative to conventional enhanced oil recovery methods because it is eco-friendly and economically advantageous. However, the knowledge about the composition and diversity of microbial communities in artificially regulated reservoirs, especially after activating petroleum hydrocarbon-degrading bacteria (PHDB) by injecting exogenous nutrients, is still insufficient. This study utilized a combination of high-throughput sequencing and metagenomics technology to reveal the structural evolution characteristics of the indigenous microbial community in the reservoir during the PHDB activated for enhanced oil recovery, as well as the response relationship between the expression of its oil production functional genes and crude oil biodegradation. Results showed that Pseudomonas (>75%) gradually evolves into a stable dominant microbial community in the reservoir during the activation of PHDB. Besides, the gene expression and KEGG pathways after crude oil undergoes biodegradation by PHDB show that the number of genes related to petroleum hydrocarbon metabolism dominates the metabolism (21.98%). Meanwhile, a preliminary schematic diagram was drawn to illustrate the evolution mechanism of the EOR metabolic pathway after the targeted activation of PHDB. Additionally, it was found that the abundance of hydrocarbon-degrading enzymes increased significantly, and the activity of alcohol dehydrogenase was higher than that of aldehyde dehydrogenase and monooxygenase after PHDB activation. These research results not only filled in and expanded the theoretical knowledge of MEOR based on artificial interference or regulation of reservoir oil-recovery functional microbial community structure but also provided guidance for the future application of MEOR technology in oil field operations.

Enhancing Biodegradation of Spent Oil in Soil through Autochthonous Bioaugmentation

Enhancing Biodegradation of Spent Oil in Soil through Autochthonous Bioaugmentation

Biodegradation of Spent Oil in Soil Using Citrullus Colocynthis Peels and Other Plant Wastes

Spent oil, which contains hazardous substances that pose health risk to man and his environment, are disposed indiscriminately on land in most mechanic workshops. The waste oil find its way into farmland and water bodies causing contamination of water, plants and lands. The ingestion of contaminated water, plants and animals lead to serious health issues. The abilities of plant wastes such as Citrullus colocynthis peels were investigated for the enhancement of the biodegradation of spent oil in soils. Contaminated soil in microcosms, A to J, were treated with plant wastes, duplicated to give 20 microcosms and incubated for 180 days. Periodic soil sampling from each microcosm was followed by cold extraction with dichloromethane and residual oil were analysed via Gas Chromatography/ Mass Spectrometry techniques (GC/MS). The results showed that the biostimulants accounted for 55.2 % of the total variation in the biodegradation result, P<0.001 at α = 0.05. The compounds identified ranged from C10- C35. The highest molecular weight compounds were 17-Pentatriacontene, 490.93 g/mol and 1-Hexacosene, 490.93 g/mol, while the lowest was p-Menth-8(10)-en-9-ol, cis, 154.25 g/mol. The compounds with the highest and lowest area percentage, 36.04 % and 0.97 % were 9-Octadecenamide, (Z)-, and 9, 9-Dimethyl-9-sila-9,10-dihydrophenanthrene respectively. About, four alkanes, six alkene, fourteen oxygenated, five nitrogen containing- and eight aromatic- compounds were identified after biodegradation. There was no statistical significant difference between the performances of each of the stimulant in the microcosms, P>0.1 at α = 0.05. There was an extremely significant difference between the performance of the stimulated microcosms and the natural attenuation containing NaN3, with P<0.001 at 0.05 significant level. The results show that plant wastes have abilities to enhance the biodegradation of the spent oil. Hence, Citrullus colocynthis peels generated in the Northern Nigeria and other plant waste can be used for cost-effective and safe degradation of spent and crude oil in the Southern Nigeria for the reclamations of lands for agricultural purposes.

Microorganisms immobilized hydroxyethyl cellulose/luffa composite sponge for selective adsorption and biodegradation of oils in wastewater

The highly efficient removal of oils such as oils or dyes from wastewater has aroused wide concern and is of great significance for clean production and environmental remediation. The synthesis of a novel aerogel (designated as HEC/LS) is reported herein, achieved through a sol-gel method followed by freeze-drying utilizing loofa and hydroxyethyl cellulose as the raw materials. The new HEC/LS aerogel exhibits excellent porosity and specific surface area, with a porosity of 88.70 %, a total pore area of 0.607 m2 g−1, and a specific surface area of 230 m2 g−1. The prepared HEC/LS aerogel exhibits exceptional hydrophilicity and self-floatability, facilitating its rapid absorption of water up to 21 times its own weight within a mere 3 s. Additionally, it demonstrates good adsorption performance for methylene blue (MB), with a maximum adsorption capacity of 83.30 mg g−1. Subsequently, a new hydrophobic microorganisms-loaded composite aerogel (namely, Bn-HEC/LS) was obtained by doping microorganisms into the as-prepared HEC/LS in multiple enrichment followed by a hydrophobic and oleophilic surface modification. Based on its rich porous structure and oleophilic wettability, the as-synthesized Bn-HEC/LS exhibits excellent selective adsorption and degradation properties for the oil contamination, the diesel oil could be selectively absorbed in the Bn-HEC/LS and degraded by the loaded microorganisms. Among them, B5-HEC/LS displays the highest removal efficiency of 94.50 % within 180 h, while free microorganisms and HEC/LS aerogels show degradation efficiencies of only 21.70 % and 48.10 %, respectively. The fixation of microorganisms in the aerogel increases their number within the material and enhances the relative microorganisms removal capacity. The hydrophobic and lipophilic modifications improve the selective adsorption performance of the aerogel on diesel oil, resulting in a significantly high removal rate of Bn-HEC/LS for diesel oil. The results indicate that the immobilization of microorganisms into aerogel improves the activity of microorganisms, and the hydrophobic and oleophilic modification enhances the selective adsorption performance of aerogel to diesel oil, thus resulting in a very high removal rate of Bn-HEC/LS for diesel oil. This study is expected to provide a now possibility for the green and efficient bioremediation of oils.

Бактерии-деструкторы с ростстимулирующими свойствами для использования в экологической

A topical research trend in ecological biotechnology is the search and study of microorganisms-destructor resistant to additional pollutants and growth-stimulating to remediant-plants. Four strains of hydrocarbon-oxidizing microorganisms isolated from soil samples were identified on the basis of cultural-morphological, physiological-biochemical properties and a comparative analysis of the gene encoding 16S rRNA. The bacteria Acinetobacter calcoaceticus UOM 22 and UOM 29, A. courvalinii UOM 35 showed a significant degree of oil biodegradation in a liquid medium at 24 and 8 °C (93.0–95.6% and 78.4–81.1%, respectively). In the same conditions these indicators were 44.8 and 33.7%, respectively for strain Rhodococcus erythropolis UOM 33. All microorganisms grew in the presence of aromatic hydrocarbons (including polycyclic hydrocarbons), were resistant to NaCl (5–7%) and lead ions (1.00–1.25 g/L). They were capable of nitrogen fixation and inorganic phosphate dissolution, indole-3-acetic acid synthesis (150–1416 ng/ml of culture liquid) and hydrolytic enzyme lipase production. We found that A. calcoaceticus UOM 22 and A. courvalinii UOM 35 strains increased the barley seeds germination by 8.6 and 10.5%, as well as A. calcoaceticus UOM 29 and A. courvalinii UOM 35 stimulated the barley root growth by 16.3 and 18.1% respectively. The results of the experiments indicate the possibility of using A. calcoaceticus UOM 22 and UOM 29, and A. courvalinii UOM 35 strains for cleaning oil-contaminated soils, including in combination with remediant-plants.

Bioremediation of Heavily Contaminated Sandstone from Bida Basin: A pre-emptive model for hydrocarbon exploration in the basin using Bacillus Sustilis and Cereus spp

Petroleum, often known as crude oil, is a complex organic mixture that naturally exists beneath the surface. There is often extreme pollution and other dangerous conditions associated with its exploration, production, refining, storage, and distribution activities. Thus, it is vital to carefully consider the best options after hydrocarbons are found in the Bida Basin, especially in regards to oil spills. In order to prevent this, this study created a preventive model by contaminating samples of sandstone from the Doko Member of the Bida Basin with spent engine oil, which is known to contain a higher percentage of nitrogen and sulfur compounds, aromatic and aliphatic hydrocarbons, and metals like manganese, calcium, zinc, and lead than fresh oils. Two (2) bacterial isolates with a high potential for engine oil biodegradability—Bacillus Subtilis and Cereus—were utilized to assess the effectiveness of total petroleum hydrocarbon (TPH) removal, which is a crucial aspect of crude oil detection. A weekly monitoring program was used to track various physicochemical characteristics of the wasted engine oil, including pH, bacterial biodegradation rate, total petroleum hydrocarbon, nitrate, phosphate, and total organic carbon content. After fourteen and twenty-eight days of contamination, respectively, the test results showed ~50% to <70% biodegradation rate. So, when hydrocarbon development in the Bida Basin begins in earnest, NNPC will have access to first-hand technology for environmental cleanup at a very cheap cost, demonstrating the effectiveness of Bacillus Cereus and substilis as hydrocarbon biodegradation tools.

Geochemistry and accumulation of the ultra-deep Ordovician oils in the Shunbei oilfield, Tarim Basin: Coupling of reservoir secondary processes and filling events

Ultra-deep (7300 m–8900 m) condensed and volatile oil reservoirs have been discovered in the Ordovician reservoirs of the Shunbei oilfield, in the Tarim Basin. This study describes the petroleum accumulation process in the Shunbei oilfield by combining an analysis of its geochemical characteristics with seismic section observations and an analysis of petroleum filling events. Geochemical techniques are used to determine the sources, maturity, secondary processes, accumulation periods, and timing of petroleum filling. Analysis of fluid inclusion homogenization temperatures and burial-thermal histories indicates distinct petroleum filling events. Specifically, the north sub-section of the No. 5 fault zone experienced two petroleum filling periods during the late Caledonian and Indosinian epochs while the No. 1 fault zones and the mid-south sub-sections of the No. 5 fault zones experienced three distinct filling periods, encompassing the late Caledonian, Indosinian, and Himalayan periods. The CO2 concentrations and δ13CCO2 values suggest the presence of secondary microbial gases, primarily thermogenic gases. Gas component analysis reveals a transition from kerogen degradation gas to oil cracking gas from north to south. The detection of intact n-alkanes and compounds of the 25-norhopanes series in oil samples suggests a mixture of early biodegradable oil with late fresh oil in the area. Seismic sections reveal diabase intrusions with strong axial reflections. Local hydrothermal activities during the Permian era rapidly cracked saturated hydrocarbon biomarkers, forming polycyclic aromatic hydrocarbons in the oil. Hydrothermal activity in the south sub-section of the No. 5 fault zone depleted the hydrocarbon-generating capacity of the underlying source rocks. Petroleum charged during the Indosinian period likely originated from potential petroleum reservoirs in the Cambrian system. This explains the comparatively low temperature of the SHB57X reservoir (163.32 °C) and the lack of strong hydrothermal activity in the late stage, but no biomarkers of the second-stage charged oil have been detected. Biomarker detection and gas genesis in the mid-south sub-section of the No. 5 fault zone and in the No. 1 fault zone suggest weak or no hydrothermal activity, with Cambrian source rocks maintaining their hydrocarbon generation capacity. Gas filling in the Himalayan period caused evaporative fractionation in the original reservoirs, resulting in a disproportionate (2-MH+2,3-DMP)/(3-MH+2,4-DMP), producing high K1 values in the light hydrocarbons in the present petroleum reservoirs. Differences in gas charging events in the Himalayan period led to the present distribution of petroleum phases.