一株高效烷烃降解菌Acinetobacter sp. LAM1007的分离鉴定及降解特性

【目的】挖掘高效烷烃降解菌,为后续石油烃污染修复工程提供优良菌种资源。【方法】以正十六烷为唯一碳源,将大庆石油污染土样中分离筛选到的高效烷烃降解菌经形态观察、生理生化试验、细胞化学组分及16SrRNA基因序列分析等方法进行初步鉴定与系统分类;同时通过单因素试验研究环境因素(温度、pH、接种量和转速)以及不同初始浓度的正十六烷(0.1%、0.3%、0.5%、1.0%、1.5%、2.0%,体积比)对菌株降解效率的影响。【结果】筛选到一株高效烷烃降解菌LAM1007,经初步鉴定该菌株为不动杆菌属(Acinetobacter)。该菌株在添加正十六烷的无机盐培养基中的最适降解条件为:30°C,pH 7.0,接种量1%(体积比),转速180 r/min,在该条件下浓度为0.3%(体积比)的正十六烷60 h内降解率高达90%。【结论】菌株LAM1007是一株在石油烃污染修复方面极具应用潜力的高效烷烃降解菌。     

小黑麦对石油污染盐碱土壤细菌群落与石油烃降解的影响

为了研究小黑麦对石油污染盐碱土壤中的细菌群落与石油烃降解率的影响,采用高通量测序技术,设置0 g/kg,1 g/kg和5 g/kg三个石油浓度,以未种植小黑麦的土壤作为对照,对6组不同处理的盐碱土壤样品的细菌群落结构及其多样性进行测定,并分析土壤中的石油烃降解率。结果表明:在土壤石油浓度为1 g/kg和5 g/kg时,小黑麦根际土壤中的石油烃降解率相较对照组分别提高了36.67%和33.20%。从6个土壤样品中分别获得21398—27899条测序序列。在石油污染土壤中,小黑麦根际土壤的细菌群落多样性和丰度均大于对照组的土壤。同时,在"门","纲","属"的分类水平上,小黑麦根际土壤细菌群落中的一些根际细菌的相对丰度增加了,主要包括变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、γ-变形菌纲(Gammaproteobacteria)、烷烃降解菌科-未命名菌属(Alcanivoracaceae_norank)、黄单胞菌属(Xanthomonas)、亚硝化单胞菌-不可培养菌属(Nitrosomonadaceae_unculture)等。有一些相对丰度增加的根际细菌是以石油及石油分解物为碳源的微生物。本研究证明种植小黑麦改变了石油污染盐碱土壤根际土壤细菌群落结构组成和多样性,促进了降解石油微生物群落的构建,显著提高了盐碱土壤石油污染的降解效果。研究结果为石油污染盐碱土壤的植物修复奠定了理论基础。     

辽河油田土壤石油污染及其微生物群落特征

本研究采取辽河油田曙光采油厂、欢喜岭采油厂和锦州采油厂井场周边土壤,并以未污染稻田土壤作为对照,分析了各采样点的土壤理化性质、石油烃浓度组成及土壤微生物群落结构。结果表明: 1) 3个采油厂井场周边土壤均受到严重的石油烃污染,但其石油烃浓度及组成存在一定的差异,曙光和欢喜岭采油厂土壤石油烃平均浓度是锦州采油厂的2倍以上;曙光采油厂土壤中胶质沥青质含量最高,而欢喜岭和锦州采油厂土壤中烷烃含量最高,比例均在40%以上。2)与稻田土壤相比,锦州采油厂土壤微生物操作分类单元(OTU)、Chao1指数和Shannon指数升高,而其在曙光和欢喜岭采油厂土壤中降低;各采油厂土壤样品中存在相同的优势菌门及菌属,但丰度存在较大差异。锦州采油厂土壤中分枝杆菌属、假单胞菌属的丰度高,曙光采油厂土壤中鞘氨醇单胞菌属、类诺卡氏菌属、马赛菌属的丰度高,而欢喜岭采油厂土壤中溶杆菌属、硫杆菌属、假节杆菌属的丰度高。3)相关分析表明,鞘氨醇单胞菌属、类诺卡氏菌属、硫杆菌属、马赛菌属、假节杆菌属与总石油烃、总有机碳和胶质沥青质含量呈显著正相关,分枝杆菌属、溶杆菌属、假单胞菌属与总氮和总磷呈显著正相关。本研究系统分析了不同采油厂土壤中石油烃、土壤理化性质和微生物群落特征,揭示了辽河油田污染土壤中特定的优势菌属和群落结构,为辽河油田石油烃污染土壤修复功能微生物筛选及修复过程菌群构建提供理论依据,也为其他油田高效降解菌筛选提供了方法借鉴。     

Biodegradability of polar compounds formed from weathered diesel

Once released into the environment, petroleum is exposed to biological and physical weathering processes which can lead to the formation and accumulation of highly recalcitrant polar compounds. These polar compounds are often challenging to analyse and can be present as an “unresolved complex mixture” (UCM) in total petroleum hydrocarbon (TPH) analyses and can be mistaken for natural organic matter. Existing research on UCMs comprised of polar compounds is limited, with a majority of the compounds remaining unidentified and their long-term persistence unknown. Here, we investigated the potential biodegradation of these recalcitrant polar compounds isolated from weathered diesel contaminant, and the changes in the microbial community composition associated with the biodegradation process. Microcosms were used to study the biodegradability of the polar compounds under various aerobic and anaerobic conditions and the results compared against the biodegradation of fresh diesel. Under all conditions tested, the majority of the polar UCM contaminant remained recalcitrant to biodegradation. The degradation was limited to the TPH portion of the polar UCM, which represented a minor fraction of the total polar UCM concentration. Changes in microbial community composition were observed under different redox conditions and in the presence of different contaminants. This work furthers the understanding of the biodegradation and long-term recalcitrance of polar compounds formed through weathering at contaminated legacy sites.     

采用酶液活性测定法快速筛选及构建石油烃高效降解菌系

快速筛选复杂有机物降解微生物混合菌系,在污染物治理过程中具有重要的实践意义.本研究首次尝试利用MicroResp^TM技术分析微生物酶液活性的方法,快速标定高效降解菌及混合菌系的石油烃降解能力,并采用传统的摇瓶培养检测法予以验证.通过微生物胞内、胞外及混合酶液的活性分析,考察了不同酶系(胞外、胞内及混合酶液)、菌系对石油烃分子的降解情况.结果表明: 结合MicroResp^TM技术的酶液活性测定法能够快速检测石油烃代谢酶系的降解能力,其灵敏度好、通量高,与传统的菌株摇瓶培养方法的检测结果基本一致.其中,7株菌株的120种全组合菌系活性测定试验在12 h周期内1次完成.筛选周期由传统摇瓶培养所需的7 d缩短10倍以上.以酶活性测定结果为指导设计的复配菌系具有较高的降解效率,最高石油烃降解率达(56.1±1.6)%.表明本筛选方法精度高、通量高,可用于石油烃降解功能菌系的构建.     

胜利油田采油区土壤石油污染状况及其微生物群落结构

基于不同开采年代新油井(2011—)和老油井(1966—2003年)周边土壤的调查取样,研究了采油区土壤石油污染状况,利用PCR-DGGE和克隆测序技术,探讨了新、老油井周边土壤微生物的群落结构.结果表明:油井周边土壤均受到不同程度的石油污染,其石油烃含量大多高于土壤石油污染临界值(500 mg·kg^-1),且老油井周边土壤污染水平更高.污染土壤石油烃含量与土壤有机碳、全氮和速效钾含量呈显著正相关.老油井周边土壤微生物群落多样性指数随污染水平的增大而减小,新油井则呈相反的趋势.DGGE图谱优势条带测序结果表明,油井周边土壤均存在明显的优势菌,大多为石油烃相关菌和烃类降解菌,如微杆菌属、链霉菌属、迪茨氏菌属、黄杆菌属及α、γ变形菌等.
     

Use of Rice Husk as Bulking Agent in Bioremediation of Automobile Gas Oil Impinged Agricultural Soil

Evaluation of rice husk (RH) as bulking agent in bioremediation of automobile gas oil (AGO) hydrocarbon polluted agricultural soil using renewal by enhanced natural attenuation (RENA) as control was the subject of the present investigation. The effect of different parameters such as total petroleum hydrocarbon (TPH), dehydrogenase activity (DHA), optical density and pH on bioremediation performance were evaluated. The studied parameters such as microbial dynamics, percentage degradation and DHA were found to be higher in RH-amended system and differed significantly with control at P < 0.05. RH resulted in high removal efficiency of 97.85 ± 0.93% under a two-month incubation period, while RENA had lesser removal efficiency of 53.15 ± 3.81%. Overall hydrocarbon biodegradation proceeded very slowly in the RENA particularly from week 0 to 4. Experimental data perfectly fitted into the first-order kinetic and generated high r² values (0.945), first-order degradation constant (0.47 day^?1), and shorter degradation half-life (1.50 d)—t_1/2 = Ln2/K and Ln2 numerically equals to 0.693 and hence written as 0.693/K. Micrococcus luteus and Rhizopus arrhizus were isolated in the present study, which displayed extreme AGO hydrocarbon biodegradative abilities. The use of RH in hydrocarbon-polluted soil significantly increased biodegradation rate and resulted in effective AGO cleanup within 2 months period. Therefore, RH provides an alternative source of bioremediation material in field application for abundant petroleum hydrocarbon soil pollution.     

Empirical Models Estimating Carbon Dioxide Accumulation in Two Petroleum Hydrocarbon–Contaminated Soils

Bioremediation is a popular method in degrading diesel fuel contaminants from soil. Bioremediation can be enhanced by estimating the effect of important environmental parameters on microbial activity. Respirometry was used to develop empirical models describing the effects of temperature, moisture, nitrogen, and phosphorus concentration on microbial activity in a diesel-contaminated soil from Wyoming. Carbon dioxide (CO₂) data were analyzed using a base equation where its coefficient values were functions of each parameter. Two physiologically different groups of microorganisms were identified from the results under different operating temperatures. The empirical correlations were combined into one model and this model was tested against a hydrocarbon-contaminated soil collected from a site in Egypt with similar history of contamination. The predicted CO₂ evolution agreed well with the actual data obtained from the Egyptian soil samples, showing a sound predicting power of the empirical model for petroleum hydrocarbon biodegradation. Overall, the empirical correlations developed from the respirometric data provide a method to describe microbial activity in diesel-contaminated soils.     

Dynamic determination of anaerobic acetate kinetics using membrane mass spectrometry

A small, stirred, 14.4-mL tank reactor was designed to serve as a measurement cell for short-term investigation of microbial kinetics. A mass spectrometer membrane probe allowed the measurement of the dissolved gases of hydrogen, methane, oxygen, and carbon dioxide. pH was measured by an electrode and controlled by addition of acid or alkali. The highly sensitive measurement of gases with low solubility allowed rapid measurements at very low conversion. In kinetic experiments, a stepwise increase of substrate concentration (method A) and continuous feed of substrate (method B) were used, allowing quick estimation of substrate kinetics. Acetate conversion in mixed culture biofilms from a fluidized bed reactor was investigated. Substrate inhibition was found to be negligible in the concentration range studied. Experiments at various pH values showed that the undissociated acid form was the kinetic determinant. Kinetic parameters for Haldane kinetics of protons were KSH = 1.3 x 10(-5) mol m-3 and KIH = 8.1 x 10(-3) mol m-3. With free acid (HAc) as the rate determining species, the kinetic parameters for method A were KSHAc = 0.005 mol m-3 and KIHAc = 100 mol m-3 and for method B were KSHAc = 0.2 mol m-3 and KIHAc = 50 mol m-3. The maximum biomass activity occurred at around pH 6.5. Acetate was exclusively converted to methane and CO2 at pH > 6. Copyright 1998 John Wiley & Sons, Inc.     

Effects of diurnal temperature variation on microbial community and petroleum hydrocarbon biodegradation in contaminated soils from a sub‐Arctic site

Contaminated soils are subject to diurnal and seasonal temperature variations during on‐site ex‐situ bioremediation processes. We assessed how diurnal temperature variations similar to that in summer at the site from which petroleum hydrocarbon‐contaminated soil was collected affect the soil microbial community and the extent of biodegradation of petroleum hydrocarbons compared with constant temperature regimes. Microbial community analyses for 16S rRNA and alkB genes by pyrosequencing indicated that the microbial community for soils incubated under diurnal temperature variation from 5°C to 15°C (VART5‐15) evolved similarly to that for soils incubated at constant temperature of 15°C (CST15). In contrast, under a constant temperature of 5°C (CST5), the community evolved significantly different. The extent of biodegradation of C10–C16 hydrocarbons in the VART5‐15 systems was 48%, comparable with the 41% biodegradation in CST15 systems, but significantly higher than CST5 systems at 11%. The enrichment of Gammaproteobacteria was observed in the alkB gene‐harbouring communities in VART5‐15 and CST15 but not in CST5 systems. However, the Actinobacteria was abundant at all temperature regimes. The results suggest that changes in microbial community composition as a result of diurnal temperature variations can significantly influence petroleum hydrocarbon bioremediation performance in cold regions.     

Application of a Bayesian nonparametric model to derive toxicity estimates based on the response of Antarctic microbial communities to fuel‐contaminated soil

Ecotoxicology is primarily concerned with predicting the effects of toxic substances on the biological components of the ecosystem. In remote, high latitude environments such as Antarctica, where field work is logistically difficult and expensive, and where access to adequate numbers of soil invertebrates is limited and response times of biota are slow, appropriate modeling tools using microbial community responses can be valuable as an alternative to traditional single‐species toxicity tests. In this study, we apply a Bayesian nonparametric model to a soil microbial data set acquired across a hydrocarbon contamination gradient at the site of a fuel spill in Antarctica. We model community change in terms of OTUs (operational taxonomic units) in response to a range of total petroleum hydrocarbon (TPH) concentrations. The Shannon diversity of the microbial community, clustering of OTUs into groups with similar behavior with respect to TPH, and effective concentration values at level x, which represent the TPH concentration that causes x% change in the community, are presented. This model is broadly applicable to other complex data sets with similar data structure and inferential requirements on the response of communities to environmental parameters and stressors.     

Degradation of mineral oils by a selected microbial association

A series of microbial associations capable of degrading various petroleum oils, emulsols, and crude oil were obtained by selection during periodic or continuous cultivation. The formation of these associations and oil-product degradation occurred most efficiently during aerobic flow cultivation. Under these conditions, oils were degraded by 92% on average. The microbial degradation of a petroleum oil depended on its brand, concentration, emulsification, and aeration.     

Bioremediation and phytoremediation of total petroleum hydrocarbons (TPH) under various conditions

Remediation of contaminated soils is often studied using fine-textured soils rather than low-fertility sandy soils, and few studies focus on recontamination events. This study compared aerobic and anaerobic treatments for remediation of freshly introduced used motor oil on a sandy soil previously phytoremediated and bioacclimated (microorganisms already adapted in the soil environment) with some residual total petroleum hydrocarbon (TPH) contamination. Vegetated and unvegetated conditions to remediate anthropogenic fill containing residual TPH that was spiked with nonaqueous phase liquids (NAPLs) were evaluated in a 90-day greenhouse pot study. Vegetated treatments used switchgrass (Panicum virgatum). The concentration of aerobic bacteria were orders of magnitude higher in vegetated treatments compared to unvegetated. Nevertheless, final TPH concentrations were low in all saturated soil treatments, and high in the presence of switchgrass. Concentrations were also low in unvegetated pots with fertilizer. Acclimated indigenous microbial communities were shown to be more effective in breaking down hydrocarbons than introducing microbes from the addition of plant treatments in sandy soils. Remediation of fresh introduced NAPLs on pre-phytoremediated and bioacclimated soil was most efficient in saturated, anaerobic environments, probably due to the already pre-established microbial associations, easily bioavailable contaminants, and optimized soil conditions for microbial establishment and survival.     

Optimization of <Emphasis Type="Italic">Enterobacter cloacae</Emphasis> (KU923381) for diesel oil degradation using response surface methodology (RSM)

Efficiency of Enterobacter cloacae KU923381 isolated from petroleum hydrocarbon contaminated soil was evaluated in batch culture and bioreactor mode. The isolate were screened for biofilm formation using qualitative and quantitative assays. Response surface methodology (RSM) was used to study the effect of pH, temperature, glucose concentration, and sodium chloride on diesel degradation. The predicted values for diesel oil degradation efficiency by the statistical designs are in a close agreement with experimental data (R ² = 99.66%). Degradation efficiency is increased by 36.78% at pH = 7, temperature = 35°C, glucose = 5%, and sodium chloride concentration = 5%. Under the optimized conditions, the experiments were performed for diesel oil degradation by gas chromatographic mass spectrometric analysis (GC-MS). GC-MS analysis confirmed that E. cloacae had highly degrade hexadecane, heptadecane, tridecane, and docosane by 99.71%, 99.23%, 99.66%, and 98.34% respectively. This study shows that rapid bioremoval of hydrocarbons in diesel oil is acheived by E. cloacae with abet of biofilm formation. The potential use of the biofilms for preparing trickling filters (gravel particles) for the degradation of hydrocarbons from petroleum wastes before their disposal in the open environment is highly suggested. This is the first successful attempt for artificially establishing petroleum hydrocarbon degrading bacterial biofilm on solid substrates in bioreactor.     

Degradation of Petroleum Oils by a Selected Microbial Association

A series of microbial associations capable of the biodegradation of various petroleum oils, emulsols, and crude oil were obtained by selection during periodic or continuous cultivation. Formation of the associations and oil-product degradation occurred most efficiently during aerobic flow cultivation. Under these conditions, oils were degraded by 92% on average. The microbial degradation of a petroleum oil depended on its brand, concentration, emulsification, and aeration.     

Stimulation of Diesel Fuel Biodegradation by Indigenous Nitrogen Fixing Bacterial Consortia

Abstract Successful stimulation of N₂ fixation and petroleum hydrocarbon degradation in indigenous microbial consortia may decrease exogenous N requirements and reduce environmental impacts of bioremediation following petroleum pollution. This study explored the biodegradation of petroleum pollution by indigenous N₂ fixing marine microbial consortia. Particulate organic carbon (POC) in the form of ground, sterile corn-slash (post-harvest leaves and stems) was added to diesel fuel amended coastal water samples to stimulate biodegradation of petroleum hydrocarbons by native microorganisms capable of supplying a portion of their own N. It was hypothesized that addition of POC to petroleum amended water samples from N-limited coastal waters would promote the growth of N₂ fixing consortia and enhance biodegradation of petroleum. Manipulative experiments were conducted using samples from coastal waters (marinas and less polluted control site) to determine the effects of POC amendment on biodegradation of petroleum pollution by native microbial consortia. Structure and function of the microbial consortia were determined by measurement of N₂ fixation (acetylene reduction), hydrocarbon biodegradation (¹⁴C hexadecane mineralization), bacterial biomass (AODC), number of hydrocarbon degrading bacteria (MPN), and bacterial productivity (³H-thymidine incorporation). Throughout this study there was a consistent enhancement of petroleum hydrocarbon degradation in response to the addition of POC. Stimulation of diesel fuel biodegradation following the addition of POC was likely attributable to increases in bacterial N₂ fixation, diesel fuel bioavailability, bacterial biomass, and metabolic activity. Toxicity of the bulk phase water did not appear to be a factor affecting biodegradation of diesel fuel following POC addition. These results indicate that the addition of POC to diesel-fuel-polluted systems stimulated indigenous N₂ fixing microbial consortia to degrade petroleum hydrocarbons. Received: 29 December 1998; Accepted: 6 April 1999     

Biodegradation of petroleum hydrocarbons in estuarine sediments: metal influence

In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.     

Characterization of microbial isolates from an estuarine ecosystem: relationship of hydrocarbon utilization to ambient hydrocarbon concentrations.

Water collected at 12 sites in the Neuse River estuary of North Carolina was analyzed for total viable counts on three isolation media (Trypticase soy agar [TSA], marine agar 2216, Sabouraud agar) and total hydrocarbons by fluorescence spectroscopy. Counts of 3.9 X 10(1) to 3.8 X 10(3) cells/ml were found for total heterotrophs, well within the range commonly reported for marine and estuarine waters. Generally, marine agar 2216 gave higher counts than TSA at stations with salinities greater than 6.0 mg/ml; TSA gave higher counts than marine agar 2216 at sites with salinities less than 4.0 mg/ml. The microbial species isolated on the three media agree well with those previously reported for estuarine microbial communities. Water analyses, using XAD-2 resin and fluorescence spectroscopy, revealed petroleum hydrocarbon concentrations in the range of 5 to 79 ng/ml. Representatives of the microbial species isolated from these communities were tested individually for their ability to grow using kerosene as a sole source of carbon and energy. At all but two stations, the majority of the species isolated were able to grow on hydrocarbons, indicating that this ability is widespread even in environments not subjected to high levels of hydrocarbon pollution.     

一株不动杆菌降解石油烃的特性及关键烷烃降解基因分析

【背景】Acinetobacter sp. Tust-DM21 (GenBank登录号KX390866)是本实验室前期从渤海湾海洋石油勘探船废油收集区采集的水油混合样中分离出的一株高效石油降解菌,其对短、中、长链烷烃均表现出很强的降解能力,有较好的应用前景。【目的】从应用层面探究其最佳降解条件,同时从生物信息层面探究其降解基因的作用。【方法】将其在不同温度、pH下培养144h,通过GC-MS内标法测定石油烃各组分的变化情况,计算出其最佳降解条件;同时,通过生物信息学手段确定基因组中的降解基因,每个基因分别选择7个同源基因,对它们的蛋白序列进行比较;最后对2个降解基因在0-144 h的表达情况进行了Real-time PCR分析。【结果】Acinetobacter sp. Tust-DM21最佳降解条件为35°C、pH 8.5,该条件下对石油降解率可达97.5%,其中,对长链烷烃降解率达98.5%,对环烃为81%,对芳香烃为87%;同时,研究发现基因组中含有常见烷烃降解基因alk B(GenBank登录号MH368539)和长链烷烃降解基因alm A (GenBank登录号MH357335),2个降解基因的蛋白经比较均与其同源蛋白表现出一定的相似性,同属菌的相似性最高;通过Real-timePCR发现这2个基因在0-144 h的相对表达量随时间逐步提高。【结论】Acinetobacter sp. Tust-DM21在最佳降解条件下对石油各组分都显示出了优良的降解能力,特别对长链烷烃的降解能力尤为突出;将2个降解基因的相对表达量结合该时间段的生长趋势,证明了菌株Acinetobacter sp. Tust-DM21的生长和降解与alk B和alm A基因的上调表达存在关联。     

Metagenomic analysis of microbial communities across a transect from low to highly hydrocarbon-contaminated soils in King George Island,Maritime Antarctica

Soil samples from a transect from low to highly hydrocarbon-contaminated soils were collected around the Brazilian Antarctic Station Comandante Ferraz (EACF), located at King George Island, Antarctica. Quantitative PCR (qPCR) analysis of bacterial 16S rRNA genes, 16S rRNA gene (iTag), and shotgun metagenomic sequencing were used to characterize microbial community structure and the potential for petroleum degradation by indigenous microbes. Hydrocarbon contamination did not affect bacterial abundance in EACF soils (bacterial 16S rRNA gene qPCR). However, analysis of 16S rRNA gene sequences revealed a successive change in the microbial community along the pollution gradient. Microbial richness and diversity decreased with the increase of hydrocarbon concentration in EACF soils. The abundance of Cytophaga, Methyloversatilis, Polaromonas, and Williamsia was positively correlated (p-value = <.05) with the concentration of total petroleum hydrocarbons (TPH) and/or polycyclic aromatic hydrocarbons (PAH). Annotation of metagenomic data revealed that the most abundant hydrocarbon degradation pathway in EACF soils was related to alkyl derivative-PAH degradation (mainly methylnaphthalenes) via the CYP450 enzyme family. The abundance of genes related to nitrogen fixation increased in EACF soils as the concentration of hydrocarbons increased. The results obtained here are valuable for the future of bioremediation of petroleum hydrocarbon-contaminated soils in polar environments.