石油降解混合菌群的降解特性研究及群落结构分析

从新疆克拉玛依油田石油污染土壤中分离获得石油降解菌群KO5-2,该菌群在30°C条件下培养7 d对10 g/L总石油烃（TPH）的去除率为56.9%,并且培养3 d ,7 d和9 d后能分别去除100%的芴、98.93%的菲和65.73%的芘。从KO5-2分离得到的来自6个不同菌属的12株可培养单菌,其中只有8株具有降解原油的能力。运用变性梯度凝胶电泳（DGGE）分析不同碳源条件（包括TPH、饱和烃、芴、菲和芘）下KO5-2的群落结构,结果表明,在分别以原油和饱和烃为碳源的培养条件下菌群组成大致相同,在三种不同多环芳烃（PAHs）为碳源的培养条件下,混合菌群的群落结构存在差异。红球菌属（Rhodococcus sp.）和假单胞菌属（Pseudomonas sp.）在五种不同的碳源中均能生存,芽孢杆菌（Bacillus sp.）、鞘氨醇单胞菌属（Sphingomonas sp.）和苍白杆菌（Ochrobactrum sp.）分别是降解饱和烃、PAHs和菲的关键菌。该研究表明,生物修复过程中,混合菌群的群落结构与不同的污染物和单菌株之间的相互作用有关。     

盐碱土壤多环芳烃降解菌群筛选及其降解特性

为了强化多环芳烃（PAHs）污染盐碱土壤原位微生物修复的应用,并提供高效的菌种资源,从天津大港油田盐碱化的油污土壤中富集分离出1组高效降解菲、芘的耐盐碱菌群,分离获得可培养优势细菌5株、真菌3株,考察了该菌群对菲、芘的降解效果,并进行了其对菲、芘降解特性分析。结果表明,该菌群在菲、芘质量浓度分别为25、50和75 mg/L 的液体无机盐培养基中培养15 d,菲、芘的降解率分别达到75.3%和53.6%、 56.6%和52.0%、 25.2%和13.6%;该菌群对菲、芘降解具有较广泛的盐质量分数和 pH 值范围,在菲、芘初始质量浓度各为50 mg/L,最适盐质量分数0~2%,最适 pH 值8.6条件下, 添加质量分数0.4%葡萄糖培养15 d 后,菲、芘的降解率显著提高,达到92.1%和65.8%。细菌16S rDNA 和真菌18S rDNA 测序结果表明,该菌群由叶杆菌属（Phyllobacterium）、假单胞菌属（Pseudomonas）、盐单胞属（Halomonas）、泛菌属（Pantoea）和青霉属（Penicillium）、双曲孢属（Sigmoidea）、胶孢炭疽属（Colletotrichum）组成。     

Preparation and characterization of carbon nano-sheet powders

Carbon nanosheet films were deposited on A1 substrates by using plasma assisted chemical vapor deposition （PACVD） technique. And after being peeled off from A1 substrates, carbon nanosheet powders （CNSPs） were obtained. In Raman spectrum of carbon film, there was a strong and broadened peak at about 1,580 cm^-1, indicating a carbon diamond-like film. Atomic force microscope image showed that the carbon diamond-like film had a grain size less than 100 nm, and its surface roughness Ra was 17.95 nm in an area of 5×5 μm^2. The CNSPs were irregular sheets with curly edges and a length of several micrometers to several hundreds of micrometers. The BET surface area of CNSPs was 6.66 m^2/g with no micro-pore present, which was confirmed by N2 adsorption-desorption characterization. In the adsorption testing, when the relative pressure p/po was higher than 0.3, the adsorption behavior did not follow the Langmuir equation. The addition of CNSPs to carbon black （catalyst support） could improve hydrodesulfurization performance of carbon supported Ni-W catalysts for diesel oil.     

国际石油工程联合体承包模式风险分析与应对

国内承包商在走出国门与国际承包商及当地承包商联合承接项目的过程中,总存在很多合作问题,这些问题反映出我国承包商对联合体特有风险的研究不足。笔者从我国工程承包公司的角度出发,探讨国际工程松散型联合体中8个方面的风险,并提出应对措施,包括慎重选择联合体合作方,细化联合体协议条款,理顺联合体内部关系及责任,优化联合体组织机构以及合理向联合体各方转移风险。     

石油污染土壤微生物群落分布特征

采用高通量测序法研究东营某炼油厂不同污染程度的土壤中细菌、真菌和古菌的群落结构,分析石油污染对土壤微生物群落结构的影响.结果表明:微生物群落可操作分类单元(OTU)数量随着油污土壤油含量的增加先增多后减少;Beta多样性与土壤石油污染程度有一定的关系;受污染程度相近的土壤样品,微生物群落结构的相似度较高.细菌、真菌、古...     

耐热石油降解菌群的分离及鉴定

从新疆克拉玛依石油污染土壤中分离获得一组耐热石油降解菌群KO8-2,其生长温度为45?65℃（最适生长温度为55℃）。变性梯度凝胶电泳（DGGE）显示,KO8-2包含来自芽孢杆菌属、嗜热脂肪土芽孢杆菌属和梭状芽孢杆菌属的9株单菌。它们都属于嗜热菌,并且先前已被证明至少能够降解一种石油组分。由红外分光光度法、原油族组分分析和气相色谱法分析原油降解KO8-2。结果表明,在55°C、原油浓度为10g/ L条件下,菌群KO8-2能够利用64.33％的饱和烃,27.06％的芳香烃和13.24％的胶质,原油的去除效率达到58.73％。菌群KO8-2能够有效降解C₁₉之前的组分,C₂₀?C₃₃的正构烷烃也得到明显的降解。降解前nC₁₇/Pr和nC₁₈/Ph的比率分别为3.12和3.87,而降解后该比率分别降低为0.21和0.38。与对照样品相比,经过60d的生物降解,菌群KO8-2在堆肥反应器中的除油效率达到50.12％。     

Microbial and Enzymatic Biotransformations of Asphaltenes

Asphaltenes are considered the most recalcitrant fraction of oils. Nevertheless, there are reports with rigorous experimental procedures that clearly demonstrate the capacity of enzymes and few microorganisms to transform asphaltenes. These microorganisms, fungi and bacteria, may contain a unique or very versatile enzymatic system that allows the transformation and mineralization of the highly complex asphaltene molecules. For enzymatic reactions, the biotransformation may occur only when the asphaltenes and the enzyme are in the same phase, reducing the mass transfer limitations. In this work, literature on the biotransformations of asphaltene fraction is critically reviewed.     

利用本源微生物修复技术处理含油土壤试验研究

利用本源微生物对受石油污染土壤进行了生物修复的室内试验。研究表明,在添加双氧水电子受体和适量的营养盐后,75天内土壤中石油烃的去除率可达到62．5％;添加表面活性剂可以促进微生物对石油烃的生物降解,在添加0．05％（ω）的吐温一40后,75天内土壤中的石油烃去除率可由62．5％提高到了88．6％。试验证明对含油土壤进行生物修复是可行的。     

Promotion effect of biosurfactant on heavy-oil biodegradation

Biosurfactants have received considerable attention in the field of heavy-oil remediation processes. Heavy oil was used to isolate biosurfactant-producing and oil-degrading bacteria. According to 16S rRNA, the isolated bacteria was identified as Bacillus amyloliquefaciens. The critical micelle concentration (CMC) of the produced biosurfactant was 100 mg/L. Biosurfactant could greatly improve the properties of heavy oil and significantly improve the biodegradation. The viscosity reduction rate was from 24 to 47% over the temperature range of 30–90°C. Biodegradation rates of saturated hydrocarbon (C₁₃–C₃₃) were from 21 to 85%. The biodegradation accelerating rate of biosurfactant for different aromatic hydrocarbon series was 9.89%, 9.60%, 29.71%, 16.75%, and 10.04%. These findings demonstrate that the produced biosurfactant could be useful in environmental remediation processes.     

Extensive Biodegradation of Nigerian Crude Oil (Escravos Light) by Newly Characterized Yeast Strains

Abstract

Because microbial degradation is known to be an efficient process in the in situ decontamination of oil-bearing environments, it is believed that development of effective bioremediation strategies will be aided by microbial sourcing of novel and competent hydrocarbon degraders with a broad and unusual substrate spectrum. Thus, in keeping with this objective, two Candida strains (MN1 and MC1) isolated after a repeated batch enrichment technique were tested for their biodegradation potentials on Nigerian crude oil, Escravos light. Axenic cultures of strains MN1 and MC1 grew at a rate of 1.623 and 0.586 d^?1, respectively, in mineral salts medium supplemented with 8.4 g L^?1 of crude oil. Whereas strain MN1 degraded aliphatic fractions by 97.6% and the aromatics by 74.61%, the corresponding values obtained for MC1 were 97.2% and 67.29% during the 14-day incubation period. The gas chromatography (GC) fingerprinting of aliphatic fractions showed major degradation of heptadecane (C17), octadecane (C18), nonadecane (C19), eicosane (C20), undodecane (C21), tricosane (C23), hexacosane (C26), octacosane (C28), and nonacosane (C29) in less than 6 days, whereas nearly 100% of these fractions including the isoprenoid molecules was metabolized in 14 days. Among the aromatic fractions that were nearly eliminated during the cultivation period were naphthalene, phenanthrene, fluoranthrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthrene, and benzo(a)pyrene. Interestingly, substrate uptake studies showed that both strains grew very well on petroleum cuts, biphenyl, phenol, xylene, and quite a number of polycyclic aromatic hydrocarbons including pyrene, phenanthrene, and anthracene.     

Microbial communities of light crude from Nigeria and potential for in situ biodegradation,souring, and corrosion

Microbial communities in light crude oil were analyzed using 16S rRNA gene sequencing technique in order to determine their potential contribution to biodegradation, souring, and corrosion. Apart from the presence of Desulfovibrio in Meren oil with potential for souring and corrosion, the major threat posed by microbial community of light crude is biodegradation because majority of the microorganisms that dominated the light crude like Thauera, Halomonas, Marinobacter, Methanosaeta, Methanolobus, Planctomycetes, Pseudomonas, and Bacteroidetes are known hydrocarbon degraders. It is suspected that considerable concentrations of dissolved oxygen in the crude might have encouraged the growth of aerobic species and syntrophic utilization of substrates by hydrocarbon degrading bacteria and methanogens is likely responsible for massive degradation of oil in the storage tank.     

Bioremediation of Petroleum contaminated soils collected all around China: The extensive application and the microbial mechanism

A commercial microbial agent (Devoroil) was applied to study the biodegradation efficiency of four petroleum contaminated soils/sediment collected all around China. After 40 days of biodegradation, the total petroleum hydrocarbons removal rates were 41.8%, 95.7%, 84.5% and 93.5%. The soil achieved the lowest biodegradation efficiency was chosen to conduct another bioremediation experiment to study the degradation dynamics of petroleum and the microbial mechanism. The results showed that biodegradation dynamics correspond to a negative index relation. The analysis of PCR-DGGE exhibited that Thioalkalivibrio sp., Nocardia sp. and Mycobacterium sp. were probably the dominant functional microbes in the contaminated environment.     

Soil Microbial Degradation of Vacuum Residue

Abstract

The effect of microbial consortia on the alteration of petroleum residual structure and portions was studied, which can propose an alternative or complementary method for stringent upgrading heavy crude oil methods, which consist of heavy and complex hydrocarbons. Biological processing of petroleum heavy fractions and residua may provide an alternative or complementary process in refining heavy crudes—the dominant refinery feed in the future—with less severe process conditions and higher selectivity to upgrade heavy fractions of crude oil. The primary objective was to observe the ability of an indigenous bacterial consortium taken from a soil bellow the vacuum column contaminated with vacuum residue (VR) for several decades from the Tehran refinery distillation unit, in degradation of residua components. Enrichment with VR, as sole source of carbon and energy, is the selected biosurfactant-producing microbial consortium. The biodegradation of net VR using indigenous consortia from this specific ecosystem was studied. The considered period of biodegradation of these heavy hydrocarbons was remarkably shorter than usual studies. Bacterial growth and VR biodegradation ability of this consortium analyzed with SARA test in 20 days. Studying the inoculum size and aeration effect revealed the significance of oxygen for this consortia activity and the similarity of 7% and 5% inoculation on alteration percentage of alkane, aromatic, and asphaltene and resin in VR. Results study revealed a 30.4%, 6.9%, and 9.4% decrease in the asphaltene, aromatics, and saturated aliphatic contents of VR, respectively, in only 20 days in 30°C at 150 rpm.     

Enhanced Bioremediation of Petroleum Contaminated Soils through Cold-adapted Bacteria

The aim of this article is to develop an innovative microbial-enhanced aerobic bioremediation technique, which is viable within a western Canadian context where cold climate conditions exist. Soil samples from the petroleum contaminated Cantuar site, which is located in southwestern Saskatchewan, were picked up. A specific cold-adapted strain was screened and acquired. A regeneration/re-enhancement technology was then developed to obtain strains with highly environmentally adapted specifics. The performance of isolated inocula for bioremediation enhancement was examined in a batch scale reactor. Benzene removal rate in soil slurry was significantly increased after 45 days of treatment, resulting in that the added screened bacteria could adapt to the inherent cold environment and had enhanced the efficiencies of biodegradation. Relations among contaminants removal rate, microbial growth, and production of biosurfactants were tracked as well. Results showed a better understanding of the microbial activities during the biodegradation.     

Enhanced Bioremediation of Petroleum Contaminated Soils through Cold-adapted Bacteria

Abstract

The aim of this article is to develop an innovative microbial-enhanced aerobic bioremediation technique, which is viable within a western Canadian context where cold climate conditions exist. Soil samples from the petroleum contaminated Cantuar site, which is located in southwestern Saskatchewan, were picked up. A specific cold-adapted strain was screened and acquired. A regeneration/re-enhancement technology was then developed to obtain strains with highly environmentally adapted specifics. The performance of isolated inocula for bioremediation enhancement was examined in a batch scale reactor. Benzene removal rate in soil slurry was significantly increased after 45 days of treatment, resulting in that the added screened bacteria could adapt to the inherent cold environment and had enhanced the efficiencies of biodegradation. Relations among contaminants removal rate, microbial growth, and production of biosurfactants were tracked as well. Results showed a better understanding of the microbial activities during the biodegradation.     

Effects of Combined Stress from Salt and Herbicide on Microbial Remediation of Soil Contaminated by n-Hexadecane and Phenanthrene

In this study, physicochemical, cluster, and high-throughput sequencing analyses were used to investigate the joint effects of salt and herbicide(glyphosate) stress factors on the microbial remediation of soil contaminated by n-hexadecane and phenanthrene. Based on the soil’s physical and chemical properties, differences in microbial quantity and enzyme activities were analyzed among the samples, and how that influenced distribution of soil community structure was focused upon. After 120 days of...     

蒽和菲加氢反应热力学分析

利用热力学软件计算了三环芳烃蒽和菲加氢反应过程的热力学,分析了反应过程的可行性。考察了温度对蒽和菲加氢的反应自由能(G)和lgK(K为平衡常数)的影响规律,以及温度和压力对反应体系含氢基平衡组成的影响。实验结果表明,在蒽加氢体系中,随温度的升高,部分加氢产物四氢蒽的平衡含量存在最大值;在热力学上蒽加氢生成trans-syn-trans-式的全氢蒽比生成cis-trans-式的全氢蒽更易自发进行。在菲加氢体系中,随温度的升高,部分加氢产物四氢菲的平衡含量有一最大值;在热力学上trans-anti-trans-式的全氢菲比其他全氢菲更易自发生成。这些计算为选择多环芳烃加氢过程的操作参数和条件提供了依据。     

Optimization of biodegradation of polycyclic aromatic sulfur heterocycles in soil using response surface methodology

Abstract

This paper uses response surface methodology based on the Box-Behnken design to investigate the influence of substrate concentration, inoculation quantity and temperature on the biodegradation of polycyclic aromatic sulfur hydrocarbons in oil-contaminated soil by Pseudomonas sp. LKY-5. Substrate concentration is identified as the most important factor through the analysis of variance. The maximum degradation of PASHs can be achieved at the conditions of substrate concentration of 75.77?ml/kg, inoculation quantity of 20.4% and temperature of 30?°C.