分子微生物生态学技术在中国油田开发中的应用

分子微生物生态学技术近年来在研究油藏环境中微生物群落和生态系统等方面得到了广泛的应用,已经成为指导微生物采油技术开发和应用的一个不可或缺的工具.本文较系统地总结了我国利用分子微生物生态学方法研究油藏微生物群落结构的进展,其中包括大庆油田和西北部油田的16SrRNA基因序列分析,胜利油田16SrDNA的荧光标记末端多形态限制性片断分析技术(T-RFLP),以及吉林油田应用的DNA基因跟踪检测技术,并指出了存在问题和研究方向.图1参18     

油藏厌氧微生物研究进展

地下深层油藏是独特的缺氧环境,目前还没有直接的微生物学证据表明油藏中存在真正意义上的“本源微生物”,但经注水开发后的油藏中确实蕴藏着复杂的微生物区系.油藏性质决定了油藏厌氧微生物特殊的群落结构,而油藏微生物的作用也可以改变油藏的理化及地质学特性.油藏中厌氧微生物按生理类群主要可分为发酵细菌、硝酸盐还原菌、铁还原菌、硫酸盐还原菌和产甲烷古菌.本文综述了国内外近年来油藏微生物学的研究进展,简述了微生物分子生态学在油藏微生物学研究中的应用,并对当前的研究提出了一些思考.图1参37     

石油厌氧降解促进CO2的CH4转化

CO2是主要的温室气体,利用油藏进行CO2封存,并结合原油厌氧生物降解产生的H2对其进行CH4转化,将提高原油采收率,减少封存CO2长久潜在的危害.本研究以高矿化度的青海油田油井采出液为研究对象,添加碳酸氢盐进行厌氧培养,以研究其中CO2进行CH4转化的可能性.结果显示,厌氧培养体系中检测到CH4产生.且在培养过程中,碳酸氢盐添加体系内CO2相对含量降低,甲烷相对产量升高,沥青质和芳香烃组分的相对含量降低,表明青海油田油藏中存在产甲烷菌及与产甲烷过程相关的菌群,同时CO2封存利于增强原油的流动性、提高采收率.定量PCR分析表明,碳酸氢盐的添加抑制了部分微生物的生长但古菌在整个体系生命活动中的作用并未减弱,且产甲烷古菌占古菌的相对丰度明显升高.因此,在青海油田利用油藏微生物进行CO2封存并产生新甲烷能源,同时提高原油采收率具有可能性.     

特低渗透储层微生物解堵响应特征及地质主控因素

为解决特低渗透油藏高效开发存在的问题以及微生物解堵技术在特低渗油田应用效果的不稳定性,根据鄂尔多斯盆地侏罗系和三叠系特低渗储层地质特征和开发特点,结合现场应用情况,利用优选的微生物解堵体系,通过数理统计的方法分析其在特低渗储层解堵中的响应特征和主控因素.结果显示:优选的解堵体系能够适应鄂尔多斯盆地延安组和延长组油藏,与原油作用后降粘率大于60%,界面张力降低率大于85%,乳化率大于75%,解堵率大于80%,驱油效率大于14%,特低渗透储层微生物解堵响应特征表现为液量上升,含水下降,原油粘度降低,流动性提高,菌群结构稳定,并朝着有利驱油的方向发展,微生物解堵效果与堵塞物类型、剩余油饱和度、压力保持水平和纵向非均质性相关性较高,相关系数分别为0.876 3、0.965 9、0.995 2、0.905 5.综上,本研究表明微生物解堵效果不稳定的主要原因与微生物菌种的适应性、选井选层技术具有直接的关系,可为特低渗透储层微生物解堵适应性和效果预测提供依据.     

饮用水细菌内毒素污染的风险识别与分析研究进展

细菌内毒素,又称脂多糖分子或者热原,是革兰氏阴性细菌和某些蓝藻细胞壁组分,主要由菌体死亡解体后释放.内毒素是常见的外源性致热原,属于强免疫刺激剂,与多种人类疾病密切相关.由于饮用水中会滋长微生物,因此内毒素污染在饮用水中普遍存在.近年来,国外研究中饮用水的细菌内毒素污染开始受到关注,成为饮用水微生物安全领域新兴的研究方向.本文概述了细菌内毒素的物化性质和生物活性,分析了细菌内毒素在饮用水中的存在形态,综述了国内外关于地表水源、地下水源、管网末梢水和深度处理水的内毒素污染调查状况,分析了传统水处理技术、深度处理技术和饮用水消毒技术对内毒素的控制效果,探讨了饮用水中内毒素的血液暴露、呼吸暴露和胃肠暴露途径导致机体潜在的健康风险、安全阈值和相关标准,并对饮用水细菌内毒素污染研究方向进行了展望.     

微生物易利用基质对PCP厌氧降解的影响

本文主要研究了微生物易利用基质对厌氧反应器内ＰＣＰ厌氧降解性及处理效率的影响，结果表明，ＰＣＰ对厌氧污泥代谢葡萄糖有抑制作用，则适量的微重复铁利用基质有利于促进ＰＣＰ的脱氯和降解代谢，且随着反应器进水中水中ＰＣＰ的提高，达到相近降解效率所需的微生物易利用基质的需要量也相应增加；废水中ＰＣＰ剩余量和废水中糖的初始浓度呈显著负相关。     

威海市区黑松沿海防护林土壤养分和微生物的研究

对威海市区9个样地两种林型的黑松沿海防护林的土壤养分和土壤微生物进行测定和分析,结果表明:9个样地的有机质、铵态N、速效K、速效P质量分数具有较为明显的层次性,表层养分质量分数最高,向下逐渐降低,但含水量层次性不明显.海边的海滨沙土比较贫瘠,9个样地的有机质、铵态N、速效K、速效P及含水最平均值都偏低,分别为0.76 g/kg、5.20 mg/kg、11.74 mg/kg、7.53 mg/kg和3.19%,平均pH值为5.76,为偏酸性土壤.5种微生物在土壤中密度从多到少的顺序依次为细菌>真菌>放线菌>固氮菌>纤维素分解菌,细菌在土壤微生物中占绝对优势,占微生物总数的99.9%.黑松麻栎混交林土壤养分质量分数和土壤微生物数量都高于黑松纯林,表明混交林下土壤更有利于微生物的繁殖和生长.土壤有机质和水分质屠分数与细菌、真菌和放线菌数量呈显著正相关.     

秸秆还田少免耕对冲积土微生物多样性及微生物碳氮的影响

土壤微生物是耕地质量的重要指标,为阐明秸秆还田少免耕对土壤质量的影响及其机理,在成都平原(温江)冲积水稻土区,开展了水稻–小麦/油菜轮作秸秆还田培肥定位试验(2003～2008年),在小麦生长季节,系统研究了土壤耕层微生物数量和微生物生物量的变化特征.结果表明,秸秆还田翻耕与秸秆还田免耕的土壤耕层微生物总量分别增加了51.7%、12.8%,土壤微生物数量增加主要来自土壤细菌数量的增加;从小麦全生育期看,在小麦分蘖期的增加幅度高于小麦播种期和小麦收获后,有利于促进小麦养分吸收与生长发育.秸秆还田少免耕显著增加了微生物生物量,秸秆还田翻耕和秸秆还田免耕处理土壤微生物碳总量分别比对照提高74.1%、25.8%,土壤微生物氮分别提高60.2%和12.1%.秸秆还田循环利用显著增加了土壤微生物数量和生物量,有利于土壤养分循环与转化,有利于提高土壤有机质含量并改善有机质质量,是耕地质量建设的重要途径.     

流动沙漠腹地咸水滴灌林地土壤微生物的种群特征

土壤微生物种群结构和多样性研究是了解土壤物质和能量状况的重要途径之一.本文选择磷脂脂肪酸甲酯法和培养计数法,对塔里木沙漠公路防护林地土壤微生物种群特征作了分析.旨在为沙漠公路防护林地的稳定性建设提供理论支持.结果表明,塔里木沙漠公路防护林地建设后土壤微生物数量明显增加,防护林定植年限越长,土壤微生物数量越大,且细菌是优势类群,数量远大于放线菌和真菌.防护林地的建设促进了土壤微生物脂肪酸多样性的提高,脂肪酸种类显著增加,但土层间无明显差异.C14∶0、C15∶0、C16∶0、C17∶0、C18:1ω9、C18∶0、C18∶20ω6和C21∶0是林地土壤微生物脂肪酸的优势种,经主成分分析和回归分析后得出C14∶0、C16∶0、C18∶0可有效指示土壤微生物总数量;C15∶0、C17∶0可用来标记土壤细菌和放线菌;而C18∶1ω9和C18∶2ω6与土壤真菌密切相关.磷脂脂肪酸甲酯法研究结果能够较好地反映塔里木沙漠公路防护林地土壤微生物的种群结构变化.图2表4参17     

长期有机无机肥配合施用土壤中添加不同肥料养分后土壤微生物短期变化

为了阐明改变肥料养分投入后土壤微生物特性的短期变化,采集长期定位有机无机肥配施的红壤水稻土,通过室内培育试验,观测添加不同肥料养分后土壤微生物生物量碳及BIOLOG群落功能多样性的变化.结果表明,长期有机无机肥配施土壤中添加无机肥料养分短期内( 185 d)降低了15％～22％的微生物生物量碳含量和55.6％的微生物群落平均光密度；添加有机肥料养分短期内提高了8％～42％的微生物生物量碳含量和992％的微生物群落平均光密度；而不添加肥料养分短期内提高了501％的微生物群落平均光密度,降低了微生物群落均一性,但对微生物生物量碳含量影响不大.此外,添加不同肥料养分均改变了土壤微生物群落碳源代谢模式.长期配施有机无机肥土壤中添加不同肥料养分后土壤微生物生态特征发生明显变化,其差异体现在微生物生物量碳与微生物碳源利用特性的变化上.     

Mapping the niche space of soil microorganisms using taxonomy and traits

The biodiversity of microbial communities has important implications for the stability and functioning of ecosystem processes. Yet, very little is known about the environmental factors that define the microbial niche and how this influences the composition and activity of microbial communities. In this study, we derived niche parameters from physiological response curves that quantified microbial respiration for a diverse collection of soil bacteria and fungi along a soil moisture gradient. On average, soil microorganisms had relatively dry optima (0.3 MPa) and were capable of respiring under low water potentials (-2.0 MPa). Within their limits of activity, microorganisms exhibited a wide range of responses, suggesting that some taxa may be able to coexist by partitioning the moisture niche axis. For example, we identified dry-adapted generalists that tolerated a broad range of water potentials, along with wet-adapted specialists with metabolism restricted to less-negative water potentials. These contrasting ecological strategies had a phylogenetic signal at a coarse taxonomic level (phylum), suggesting that the moisture niche of soil microorganisms is highly conserved. In addition, variation in microbial responses along the moisture gradient was linked to the distribution of several functional traits. In particular, strains that were capable of producing biofilms had drier moisture optima and wider niche breadths. However, biofilm production appeared to come at a cost that was reflected in a prolonged lag time prior to exponential growth, suggesting that there is a trade-off associated with traits that allow microorganisms to contend with moisture stress. Together, we have identified functional groups of microorganisms that will help predict the structure and functioning of microbial communities under contrasting soil moisture regimes.     

A comparison of taxon co-occurrence patterns for macro- and microorganisms

We examine co-occurrence patterns of microorganisms to evaluate community assembly "rules". We use methods previously applied to macroorganisms, both to evaluate their applicability to microorganisms and to allow comparison of co-occurrence patterns observed in microorganisms to those found in macroorganisms. We use a null model analysis of 124 incidence matrices from microbial communities, including bacteria, archaea, fungi, and algae, and we compare these results to previously published findings from a meta-analysis of almost 100 macroorganism data sets. We show that assemblages of microorganisms demonstrate nonrandom patterns of co-occurrence that are broadly similar to those found in assemblages of macroorganisms. These results suggest that some taxon co-occurrence patterns may be general characteristics of communities of organisms from all domains of life. We also find that co-occurrence in microbial communities does not vary among taxonomic groups or habitat types. However, we find that the degree of co-occurrence does vary among studies that use different methods to survey microbial communities. Finally, we discuss the potential effects of the undersampling of microbial communities on our results, as well as processes that may contribute to nonrandom patterns of co-occurrence in both macrobial and microbial communities such as competition, habitat filtering, historical effects, and neutral processes.     

Study of gas-water properties under high temperature and pressure for water-soluble gas reservoirs

The physical properties of gas and water are important in usage of gas reservoirs with water and water-soluble gas reservoirs. According to the Petroleum and Natural Gas Industry Standards SY/T5542-2009 of the People's Republic of China, by applying the crude oil multistage degassing method from the “Test Method for Reservoir fluid Physical Properties” and the formation water high-pressure property testing method described in the “Theory and Application of Reservoir Fluid Phase”, this investigation employed a Ruska 2370–601A phase analyzer to obtain data regarding gas–water ratios, water volume factors, compressibility coefficients, and densities. The results showed curve trends with changes in the temperature and pressure. The gas–water ratio was compared to the gas content of subsurface samples from the X water-soluble gas reservoir, suggesting that these findings might help in the analysis of water-soluble gas reservoirs.     

Recovery of benthic communities at Macquarie Island (sub-Antarctic) following a small oil spill

Intertidal communities at Macquarie Island (sub-Antarctic) were re-evaluated seven years after a small oil spill resulting from the grounding of the “Nella Dan”, and six years after the first assessment of biological impact. Sampling was conducted to evaluate community structure in three zones of the exposed rocky shore (upper red, kelp, and lower red) and in samples of Durvillaea antarctica holdfasts. There were no significant differences between the community structure in oiled and control locations in any of the three shore zones, but holdfast macrofaunal communities at oiled sites still showed evidence of impact. Holdfast community-structure in samples from heavily oiled sites showed moderate levels of recovery, with increased abundances of species which were considered sensitive to the oiling in the first post-impact studies and decreased abundances of opportunistic polychaete and oligochaete worms. In contrast, samples collected from the moderately oiled location at Secluded Bay showed little evidence of recovery. Holdfasts at this site were filled with sediment containing traces of diesel oil, and the macrofaunal community was dominated by opportunistic worms. This study clearly indicates that even small incidents of anthropogenic perturbation can have long-lasting consequences for marine communities at Macquarie Island. Received: 23 July 1997 / Accepted: 5 February 1998     

大同盆地高砷地下水中可培养耐砷微生物的群落结构

大同盆地是典型的高砷地下水分布区。利用从地方性砷中毒严重病区山阴县采集的高砷地下水样品,用稀释培养法实验研究了外加砷源对地下水中微生物数量的影响;同时基于生物学可培养法和16SrDNA序列比对法,选取代表性高砷水样,研究了耐砷菌的种群特征。结果表明,外加砷源对地下水中微生物数量影响显著,高浓度砷会抑制大部分微生物生长,使微生物数量减少;低浓度砷对微生物生长具有一定促进作用。通过多次分离、纯化从3个不同砷含量地下水样中分离到多株砷抗性菌,经鉴定属于主要为Bacillus、Pseudomonas、Paenibacillus、Aeromonas、Enterobacter5个属。从RDP(RibosomalDatabaseProject)分析显示3个水样可培养微生物组成不同,都有生存能力强能够耐低浓度NaAsO2的Bacillales,优势耐砷菌是γ-proteobacteria,其中Enterbacter具有耐高浓度NaAsO2的能力。     

DNA damage induced by ultraviolet radiation in coral-reef microbial communities

Ultraviolet radiation (UVR) has been implicated in coral-bleaching processes and UVR may create stress to marine organisms by damage to DNA. Absorption of energy from UVB (280 to 320 nm) induces direct damage to DNA via cyclobutane pyrimidine dimer photoproduct-formation. We examined the extent of DNA damage created by UVR in coral reef microbial communities and whether the coral-surface microlayer (CSM) provides protection from UVR to the microorganisms found there. Diel patterns and depth profiles of UVR effects were examined in coral mucus (coral-surface microlayer, CSM) from Montastraea faveolata and Colpophyllia natans, and water-column samples of similar depths. UV-induced photodamage was determined using a radioimmunoassay specific for cyclobutane pyrimidine dimers (thymine dimers). Significant photodamage was detected in water-column and CSM samples, although the level of damage in CSM samples was consistently lower than in water-column samples collected from the same depth, suggesting the presence of photoprotective mechanisms within the CSM. Diel patterns of photodamage were detected in both water-column and CSM samples, but peak damage occurred earlier in the day for the CSM samples, suggesting differences in damage and repair kinetics between the water column and CSM. The results suggest that microorganisms within the CSM are afforded some protection from UVR stress and that changes in the amount of DNA damage in these organisms may be an indicator of changing UVR stress to corals. Received: 10 January 1997 / Accepted: 15 September 1997     

Impact of refined petroleum spills on water quality, macro-invertebrate and microbial communities of a tropical aquatic environment

Water quality characteristics, benthic macro-invertebrates and microbial communities of three first order streams in South West Nigeria were investigated to assess the effects of refined petroleum five months after spillage. All physical and chemical conditions except temperature and pH were significantly different (P<0.01) at the upstream control stations and impacted stations reflecting the perturbational stress. The benthic macro-invertebrate fauna were dominated by arthropods, but the faunal spectrum was dissimilar at all the stations studied. Sampling stations at the epicentre of the spill showed considerable reduction in faunal compositions and relative abundance. Generally, the microbial density and diversity were highest in both soil and water samples from impacted sites than in control sites. There was a significantly higher proportion (P < 0.05) of hydrocarbon utilizers in soil than in water samples in all stations except in samples from stations (P<0.05).     

Diversity and distribution of proteorhodopsin-containing microorganisms in marine environments

Proteorhodopsin (PR) is a recently discovered protein involved in the utilization of light energy. Several studies have shown that PR-containing microorganisms are widespread and compose a large proportion of the biomass in marine ecosystems. A better understanding of the ecological role of PR will help clarify the effect of the global flow of energy and the carbon cycle on marine communities. In this study, a bioinformatical database of PR codon sequences, the Global Distribution Database of Proteorhodopsin (GDDP), as a tool for analyzing the diversity and distribution of PR-containing microorganisms in marine environments throughout the world was designed. The community structure of PR microorganisms were also compared using PCR assays and UniFrac analyses of 12 samples collected from three water layers (0, 75, and 200 m) at four representative sites in the Pacific, Atlantic, and Indian Oceans. The results indicate that PRcontaining microorganisms can be grouped into two distribution types: widespread and location-specific. Representative cases of the former include SAR11-PR and HOT2C01-PR. Interestingly, PR communities cluster by geographic locale but not by water depth.