Hydrocarbon-Degrading Bacteria and Paraffin from Polluted Seashores 9 Years after the Nakhodka Oil Spill in the Sea of Japan

Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria （genus Pseudomonas） and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis （0.422, 0.377, and 0.250 nm d-spacing） in association with graphite and calcite after 9 years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9- year bioremediation.

Isolation and Characterization of Hydrocarbon-Degrading Bacteria from Wastewaters in Ouagadougou, Burkina Faso

Lubricants are very often found in nature under waste-oil forms and represent for the environment a real danger of pollution due to the difficulty of their biodegradation. The situation is especially worrying in most developing countries in particular those of Sub-Saharan Africa due to the absence of regulation or control. The present work aims to isolate bacterial strains able to degrade hydrocarbons which can later be used in biotechnology for environments depollution. Oil-contaminated wastewater samples were collected in Ouagadougou city (Burkina Faso) and then used as source of bacterial isolation. Appropriate amounts of samples were inoculated to a mineral salt medium (MS) with Total Quartz 9000 oil as sole carbon and energy source and then incubated for enrichment, prior to microbe isolation. Two bacterial strains namely S2 and S7 were isolated from the enrichment cultures. The strains were tested for their ability to degrade other hydrocarbons (i.e. gasoline, diesel oil, brake oil) and for temperature, pH and salt concentration ranges for growth before their biochemical characteristics were defined. Based on their morphological, physiological and biochemical traits, strains S2 and S7 belong to Acinetobacter and Pseudomonas genera, respectively.

Uptake of Polycyclic Aromatic Hydrocarbons across Bacterial Membrane

Polycyclic aromatic hydrocarbons (PAHs) are important pollutants, whose biodegradation and bioremediation with microorganisms are the promising ways to clean environments and reduce their exposure to humans. Although the transportation of PAHs across bacterial membrane is the first step forwards their biodegradation, it receives less attention. In this mini-review, we explore which transport system for uptake of carbon sources can serve for uptake of PAHs in bacteria, and try to uncover some patterns in their transport mechanisms. Collectively, 1) the major carbohydrate transport system, PTS, is unlikely to take PAHs because PAHs lack a hydroxy group for phosphorylation but aromatic acids are good candidates;2) PAHs could probably go through H+ symporters, especially the low-molecular-weight PAHs, which are partially dissolvable in water;3) it is unlikely that PAHs can produce chemiosmotic ion gradients to go through uniporters;and 4) antiporters could serve as transporters to transport PAHs across bacterial membrane only after the metabolism of PAHs generates extra H+ inside cell. Accordingly, the basic mechanism for uptake of PAHs is whether they can donate H+ in order to generate an electrochemical proton gradient to go through symporters.

The amount of hydrocarbon bacteria in the Great Wall Bay and its adjacent area

During the summer of Antarctic in 1993/1994, the species and amount of hydrocarbon bacteria of the Great Wall Bay and its adjacent sea area have been studied. Flavobacterium,Pseudomonas,Kurthia and Actinetobacter have been identified .The number of them varied from 3 cell/L to 1100 cell/L.The number in the inner bay is larger than that out of it.The dispersing is a very important way of the changing of hydrocarbon bacteria.

Molecular Characterization of Aerobic Heterohophic Bacteria Isolated from Petroleum Hydrocarbon Polluted Brackish Waters of Bodo Creeks, Rivers State Nigeria

Surface water sources in the oil producing Niger Delta region of Nigeria are highly susceptible to pollution by petroleum hydrocarbons and so it is important to understand the microbial diversity of such ecosystems. Water and sediment samples were collected between April-August, 2013 from Bodo creeks and taken to Environmental Microbiology laboratory of University of Portharcourt for analysis. A total of thirty aerobic heterotrophic bacterial strains isolated ranged from 3.0 - 7.0 × 104 cfu for surface water and 1.6 - 5.6 × 104 cfu for sediment samples of Bodo creek using serial dilution and spread plate technique. Pure cultures of bacteria were obtained on the basis of their morphological characteristics and subjected to biochemical tests and further classified on the basis of 16S rRNA gene sequence analysis. The DNA was isolated from size fractionated samples and the diversity of bacteria in each fraction was studied using PCR amplification of partial 16S rRNA. The sequences were submitted to NCBIGen bank for identification and assigning of accession numbers. The isolated aerobic heterotrophic bacteria belong to the families of Enterobacteriaceae, Bacilliceae, Alcaligenaceae, Pseudomonadaceae, Flavobactericeae and Planococcaceae.

Bioprospecting of Hydrocarbonoclastic Representative Bacteria

This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Nigeria. Heterotrophic bacteria count ranged from 8.0 × 105 cfu/gm for sample TSAS1, and 2.1 × 106 cfu/gm for sample TSAS2 while TSAS3 was too numerous to count (TNTC). Hydrocarbon utilizing bacteria count ranged from 1.1 × 105 cfu/gm for TSAS1, and 5.9 × 104 cfu/gm for TSAS2, while TSAS3 was 5.4 × 104 cfu/gm. Physiochemical parameters of the soil were determined. The ranges obtained were pH 6.6, conductivity 125 μs/cm, temperature 27.3°C, moisture 7.72, total nitrogen 0.056%, phosphate 1.554 ppm, potassium 145.87 ppm, lead 7.02 ppm, cadmium 0.41 ppm, nickel 1.96 ppm, copper 1.14 ppm, total petroleum hydrocarbon 1487.24181 ppm, polycyclic aromatic hydrocarbon 12.85287 ppm. Isolates of hydrocarbon utilizing bacteria characterized belonged to the genera Escherichia coli, Klebsiella sp., Lactobacillus sp., Enterobacter sp., Serratia sp., and Proteus sp. The findings in this study have revealed the abilities of these groups of bacteria to be employed in bioremediation/biodegradation clean-up practices. Thus the polluted soil may harbour important genera of bacterial species that may have beneficial applications in environmental microbiology for future remediation processes.

Bacteria as indicators for finding oil and gas reservoirs:A case study of the Bikaner-Nagaur Basin,Rajasthan,India

Geo-microbial prospecting for hydrocarbons is an exploration method based on the seepage of light gaseous hydrocarbons from oil/gas reservoirs to the surface and their utilization by hydrocarbon oxidizing bacteria. These bacteria utilize hydrocarbon gases as their sole source of food and are found to be enriched in the near surface soils/sediments above the oil and gas reservoirs. The detection of anomalous populations of n-pentane and n-hexane oxidizing bacteria in the surface soils can help to evaluate the prospects for hydrocarbon exploration. A geo-microbial survey has been carried out in the Bikaner Nagaur basin to investigate the prospects for hydrocarbon exploration. In the present study, bacterial counts for n-pentane utilizing bacteria range between 2.0× 10^2 and 1.26× 10^6 cfu/gm and n-hexane utilizing bacteria range between 2.0× 10^2 and 1.21 × 10^6 cfu/gm. The bacterial concentration distribution maps show four distinct anomalies in the study area. The possibility of discovering oil or gas reservoirs using the microbiological method is emphasized by the tact that the hydrocarbon-oxidizing bacteria range between 103 and 106 cfu/gm in soil/sediment receiving hydrocarbon micro-seepages. In the present study area of the Bikaner Nagaur basin, n-pentane and n-hexane utilizing bacteria are found between 105 and 106 cfu/gm of soil sample, which is significant and thereby substantiates the seepage of lighter hydrocarbon accumulations from oil and gas reservoirs. Geo-microbial prospecting studies suggest that hydrocarbon micro-seepage of subsurface origin is present in the study area and indicate that the area has positive prospects for petroleum exploration.

Diversity and distribution of bacterial community in the coastal sediments of Bohai Bay,China

In order to understand the diversity and distribution of the bacterial community in the coastal sediment of the Bohai Bay, China, high-throughput barcoded pyrosequencing of the 16S rRNA gene was used. Metagenomic DNA was extracted from the sediment samples, and was sequenced using a 454 GS FLX Titanium system. At 97% similarity, the sequences were assigned to 22 884 operational taxonomic units （OTUs） which belonged to 41 phyla, 84 classes, 268 genera and 789 species. At the different taxonomic levels, both the dominants and their distribution varied significantly among the six coastal sediments. Proteobacteria was the first dominant phylum across all the six coastal sediments, representing 57.52%, 60.66%, 45.10%, 60.92%, 56.63% and 56.59%, respectively. Bacteroidetes was the second dominant phylum at Stas S1, S2 and S4, while Chloroflexi was the second dominant phylum at Stas S3, S5 and S6. At class level, γ-Proteobacteria was the first dominant class at Stas S1,S2, S4 andS6, while δ-Proteobacteria became the first dominant class at Stas S3 and S5. In addition, a large proportion of unclassified representatives have distributed at the different taxonomic levels. Canonical correspondence analysis （CCA） results indicated that the sediment texture, water depth （D）, dissolved oxygen （DO）, total nitrogen （TN） and nine EPA priority control polycyclic aromatic hydrocarbons （PAHs） including naphthalene, acenaphthylene, acenaphthene, fluorine, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene and indeno[1,2,3-cd]pyrene were the important factors in regulating the bacterial community composition. Those results are very important to further understand the roles of bacterial community in the coastal biogeochemical cycles.

Assessing Earthworm Influence on Remediating Potentials of Soil Micro-Organisms, and Bioavailable Hydrocarbon Pollutant in the Niger Delta, Nigeria

In the Niger Delta region of Nigeria, oil explorations and exploitations abound, causing environmental pollution with serious consequences on soil ecosystem and its biodiversity. In spite of the relationship between microbes and fauna in soil ecosystem, such that both organisms can metabolize certain range of petroleum hydrocarbon substrates with the fauna influencing the remediation potentials of bacteria, yet soil fauna is still not fully considered in bioremediation. The influence of earthworm;Lumbricus terrestris on the remediating potentials of soil bacteria in petroleum hydrocarbon contaminated soils was investigated. Eighteen pots were filled with 700 g of soil each, with nine treated with mixture of 3 levels crude oil and remediated with earthworm, while the other nine had no earthworm. The total petroleum hydrocarbon (TPH), soil physical, nutrient compositions, and TPH degrading bacteria biodiversity were determined before contamination or commencement of study and thirty days after. The results showed a decrease in TPH concentration of 55.58%, 62.57% and 67.07% in 1 ml, 2 ml and 3 ml crude oil contaminated soil, respectively. Species richness and abundance of bacteria organisms increased with high relative abundance in soils remediated with earthworms, hydrocarbon utilizing bacteria increased from less than 0.1 cfu/g to 0.4 cfu/g, and total heterotrophic bacteria 1.6 cfu/g at the end of the study. Earthworms increased rate of remediation potentials of bacteria, such that within 30 days post remediation treatment, 34.14% of reduced concentration was achieved over soil samples without earthworms at 3 ml, and 25.14% at 2 ml concentration. Reduction in pH levels in remediated soils was between 6.39 to 6.17 and 6.74 to 6.72 in unremediated soils, while moisture content was 6.73% to 6.77% unremediated and 5.85% to 6.62% in earthworm remediated soils. Total organic carbon, nitrates in soils inoculated with earthworms were lower in concentration than those without earthworms. Reverse was the case with potassium, phosphate and phosphorous concentrations which were above those without earthworms. Results indicate statistically, significant difference between reduction in TPH in earthworm remediated soils and unremediated soils, pointing out that earthworm is a good candidate for facilitation of bacteria remediation-petroleum hydrocarbon contamination.

高效烃降解菌群的驯化、降解特性及初步应用

微生物技术在石油污染土壤的修复中具有广阔的应用前景,而获得具有高降解效率的菌(菌群)是保证高效修复的关键。该研究从4种不同含油土壤中驯化、培养获得稳定、高效降解石油烃的1号菌群,对其进行高通量测序,确定菌群组成;研究不同环境因素对该菌群石油烃降解能力的影响,确定了最佳降解条件;对菌群降解石油烃的特性和降解动力学进行了分析;探究了该菌群在较高浓度含油土壤中的应用潜力,以及以破碎荞麦壳为载体,将菌群固定化后修复石油烃-镉复合污染土壤的能力。结果表明,该菌群主要由寡养单胞菌属(Stenotrophomonas)、假单胞菌属(Pseudomonas)、苍白杆菌属(Ochrobactrum)、乳杆菌属(Lactobacillus)和无色杆菌属(Achromobacter)等组成;在原油质量浓度为0.5%,p H为8,盐度为1%,温度为35℃,C∶N∶P为100∶2∶1,以硝酸铵为氮源的最佳条件下,培养10 d后,菌群对石油的降解率由52.1%提高至76.6%;GC-MS分析结果显示,培养9 d和24 d后菌群对C13~C26烷烃平均降解率分别为90.3%和97%,说明该菌群能够快速高效降解中长链烷烃。菌群对原油初始浓度为0.5%和4%的降解符合一级反应动力学模型。将菌群接种于石油含量为4 631 mg/kg、8 591 mg/kg的土壤中,40 d后降解率分别为47.7%、26.4%;固定化后的菌群用于修复石油烃-镉复合污染土壤,石油烃降解率、土壤脱氢酶活性和过氧化氢酶活性高于其他组,可交换态镉的浓度低于其他组。以上结果充分显示了该菌群在石油浓度较高的土壤以及石油烃-镉复合污染土壤修复中的应用潜力。

壳聚糖固定化石油烃降解菌的降解性能研究

本研究以筛选获得的一株石油烃降解菌HYHG-06为研究对象,选择壳聚糖为固定化载体材料,戊二醛为交联剂,通过交联反应固定化制备壳聚糖固定化石油烃降解菌;通过改变降解环境的温度、初始pH、盐度及石油烃浓度,探究4个因素对石油烃降解菌降解性能的影响。结果表明,固定化菌的降解性能优于游离菌,在温度30℃、初始pH8.0、盐度3.5%、石油烃浓度1.5%的环境条件下,固定化菌的石油烃降解率高达86.62%,可开发高效消油产品,为海上石油污染提供了一种高效可行的生化处理方法。

加油站场地气相抽提(SVE)拖尾污染物的微生物降解效果研究

针对加油站场地气相抽提(SVE)拖尾污染物组成及其含量,首先利用不同浓度石油烃对活性污泥中石油烃降解微生物进行驯化、富集以及筛选,共分离出7株优质石油烃降解菌;其次利用混合降解菌群进行降解试验,对人工配制模拟石油烃污染土壤(石油烃初始质量分数约1400μg/g)生物降解180 d后,石油烃降解率大于86%;最后,开展混合降解菌对目标加油站真实污染土壤(石油烃初始质量分数1532.3μg/g)降解试验研究,结果表明,微生物混合菌群将真实污染土壤中石油烃质量分数降至342.6μg/g(230 d),满足美国堪萨斯州风险评估标准(非居民用地石油烃质量分数小于450μg/g),降解率可达77.6%。

微生物降解多环芳烃的研究进展

近年来,多环芳烃污染环境问题备受关注,其微生物降解研究取得显著进展。微生物降解作为一种高效、快速的降解方法,对减少PAHs污染具有重要意义。基于微生物降解PAHs的研究现状,探讨了其降解菌种类、影响因素及强化措施。深入研究微生物降解PAHs的机制和应用,对于环境保护和人类健康具有重要意义,未来研究需综合考虑多种因素,以实现高效、安全的PAHs降解。

水中与冰中多环芳烃衍生物对发光细菌(Vibrio fischeri)的光修饰毒性

多环芳烃衍生物(SPAHs)是一类普遍存在、来源广泛、风险隐蔽的新污染物,可由多环芳烃(PAHs)通过微生物及化学作用转化生成,其毒性甚至比母体PAHs更强,研究其环境行为和毒性效应具有重要意义.本研究选取羟基多环芳烃(OH-PAHs)、硝基多环芳烃(N-PAHs)和氯代多环芳烃(Cl-PAHs)共10种模型化合物,考察了在模拟日光(λ>290 nm)照射下,水中与冰中这些典型SPAHs对发光细菌Vibrio fischeri的光修饰毒性.毒性实验表明,对于OH-PAHs,1-羟基萘、4-氯-1-羟基萘在水中与冰中均表现出显著的光修饰毒性(P<0.05),而4-硝基-1-羟基萘仅在水相表现出较小的光修饰毒性;对于N-PAHs,1-硝基芘在水中与冰中均表现出光修饰毒性,2-硝基芴仅在冰中表现出光修饰毒性;Cl-PAHs中,仅1-氯芘在水中表现出光修饰毒性,而3种Cl-PAHs在冰中均表现出显著的光修饰毒性.通过HPLC-MS/MS分析,OH-PAHs光转化主要涉及的反应路径为取代基脱除、光氧化与苯环羟基化.以上结果阐明了SPAHs通过光化学转化可生成具有较高毒性的中间产物,对Vibrio fischeri表现为光修饰毒性,且水中与冰中的光修饰毒性具有差异,这有助于更准确评价寒冷地区这些典型新污染物的环境风险.

不同生物修复组合对石油污染的修复效应

为探究不同生物修复组合对土壤石油污染的去除效果,该研究采用室内污染暴露实验,分析了不同生物修复体系对土壤总石油烃的降解率和正构烷烃、多环芳烃2种石油烃主要成分的变化规律。结果表明,翅碱蓬单独处理组虽表现出一定的石油污染修复能力,但翅碱蓬+石油降解菌和翅碱蓬+石油降解菌+沙蚕处理组合对土壤总石油烃的降解率分别提高了12.71%和26.85%,表明联合生物修复可以更好地促进石油烃降解。翅碱蓬+降油细菌+沙蚕处理组中正构烷烃和多环芳烃组分的降解率均高于其他生物修复。多生物联合修复表现出对高碳原子数烷烃和芳烃良好的修复能力。研究结果证实,多生物联合修复组合对土壤石油污染的修复效果优于生物单独处理组,这为利用多生物联合修复组合开展滨海滩涂石油污染提供了一定的理论基础。

油气微生物勘探法

本文叙述了油气微生物勘探(MPOG)的发展历史,系统总结了MPOG的理论基础,包括MPOG的原理、物理-化学基础、微生物学基础及其理论模型,简述了MPOG的方法流程。根据国内外MPOG实践经验,论述了MPOG不受地下复杂地质条件的影响,特别适合于非构造油气藏等的主要特点,详细讨论了MPOG受油气藏性质、地层压力等影响因素,并列举了德国、美国及中国的成功实例,最后论述了MPOG的发展趋势。实践证明,采用国外研究机构—高校—油田三结合的方式是引进国外先进技术的有效途径。同时,重视培养和造就一批地质学—微生物学或微生物学、地质学多学科专门人才,发展中国自己的成套地质生物技术,必将对我国大幅度提高油气勘探成功率产生深远的影响。

海洋微生物对多环芳烃的降解

从海域沉积物中富集分离出以芘作为唯一碳源和能源的海洋微生物 ,以ST4富集培养的混合微生物作为研究对象 ;该海洋混合菌株能利用菲 (Phe)、芘 (Pyr)、荧蒽(Fla)等多种多环芳烃 ;在不同浓度的芘的降解中 ,当芘的浓度为 5 0mg/dm3 时 ,其生长水平和降解速率最高 ;当芘的浓度为 2 0 0mg/dm3 时 ,其生长受到抑制 ,芘几乎不能被降解 .外加营养盐酵母浸出液和葡萄糖促进降解微生物的生长 ,提高降解速率 .

烃降解菌株T7-2产生的生物乳化剂及其理化性质研究

从石油污染海域海底泥中筛选到的1株低温石油烃降解菌,经鉴定为红平红球菌(Rhodococcus erythropolis),命名为T7-2。该菌株能以十六烷为碳源代谢产生一种对柴油等烃类具良好乳化作用的生物乳化剂。研究表明,该乳化剂主要由糖类、脂类和蛋白质组成,其比例为55.43:31.24:12.65。进一步研究证实,该乳化剂糖类的单糖组成为甘露糖和鼠李糖;脂类由十碳、十二碳、十六碳及十八碳脂肪酸组成;蛋白质由16种氨基酸构成。本文还对乳化剂的理化性质进行了分析,发现它是一种性能稳定、乳化效率高、适应范围较为广泛的生物乳化剂,对海洋污染生物修复及石油开采都具有潜在的应用价值。

石油微生物勘探技术在西柳地区的应用

将油气微生物勘探新技术应用于西柳地区进行采样 ,并进行了烃氧化菌培养 ,根据经验确定了本研究区的 2个微生物异常区 ,即中北异常区和东南异常区。与研究区内现有已钻的 12口井相比 ,其油气微生物勘探结果的符合率为 75 % ,效果是良好的。同时 ,通过油气微生物勘探技术实践 ,总结并讨论了该技术分析结果的客观性以及地表和断层的影响因素、导致部分结果不相符的原因 ,这对我国复杂地下地质条件的油气勘探具有指导意义。最后 ,在油气微生物勘探结论的基础上 ,结合圈闭、油源等条件对试验区进行了含油性预测 。

海洋石油降解微生物的筛选及降解条件优化

从青岛港口海水中筛选出了4株适宜海洋环境的高效烃降解菌,根据传统的细菌鉴定方法将这4株菌鉴定到属,其中N1为脂肪杆菌属,N2为海球菌属,N3为微杆菌属,N4为动性球菌属。考察了温度、盐度和pH对4株混合菌生长的影响,结果表明它们都适合中性偏碱性环境生长,具有一定的耐盐性,并能耐受较低的温度,适合海洋环境。N4菌具有较宽的底物利用范围,对高浓度原油的耐受能力较强,当原油的浓度为2.5%时,其降解率仍可达到60%以上。通过构建优势混合菌发现,4株菌混合时对原油的降解能力最强。其降解原油的最佳pH=8,最佳盐度为NaCl%=3%。