贵阳喀斯特地区植被类型与季节变化对土壤微生物生物量和微生物呼吸的影响

土壤微生物特性是土壤修复的指示因子,近年来西南喀斯特地区退化土壤的相关研究较多,但不同植被类型的土壤微生物特性的变化研究相对较少。对贵阳郊区耕作土壤、灌丛、女贞人工纯林和马尾松人工纯林表层土壤（0～10cm）微生物生物量碳（SMBC）、微生物呼吸（MR）和微生物代谢熵（qCO2）的研究结果表明,土壤SMBC和MR均表现为次生林高于耕作土壤,灌丛最高;与qCO2相反,马尾松林土壤微生物活动显著弱于其他样地,不同植被类型土壤微生物活动均表现为在秋季相对较强。与植被类型的显著影响相比,季节变化、植被与季节的交互作用对SM—BC和MR的影响不明显。SMBC与土壤温度不相关,与土壤含水量呈极显著相关而土壤含水量季节变化不明显。MR与土壤温度和含水量均无显著相关性可能是季节变化对两者影响不明显的主要原因,但需要大量区域样本进一步证实。认为演替初期的灌丛比人工阔叶或针叶纯林更有利于土壤微生物群落的生长,土壤有机质积累较快,植被自然恢复是喀斯特退化土壤恢复初期更适合的徐径．     

Nucleic-acid characterization of the identity and activity of subsurface microorganisms

Received, March 1999/Revised, May 1999/Accepted, June 1999     

硅酸盐细菌煤炭脱硫实验研究

煤炭生物脱硫技术是目前和将来的重要研究内容之一.采用生长在含高硫煤培养基中的硅酸盐细菌来去除煤炭中的硫.研究结果表明,硅酸盐细菌对所用高硫煤样有脱硫效果,全硫含量从原煤样的5.45%降至处理后的3.45%,全硫脱除率达36.70%,其中细菌有效脱除率达9.91%.摇床培养的硅酸盐细菌比静止培养的硅酸盐细菌对煤炭脱硫效果更好.含氮培养基培养的硅酸盐细菌比无氮培养基培养的硅酸盐细菌脱硫效果要好.初步研究结果显示,硅酸盐细菌不仅对煤中硫化铁硫存在氧化作用,同时也对煤中有机硫和无机硫存在吸收与代谢转化作用.认为硅酸盐细菌对煤炭的脱硫作用存在两种机理:①硅酸盐细菌及其代谢产物对煤中硫产生氧化作用;②硅酸盐细菌对煤中硫进行了吸收与代谢转化.两种机理同时存在,且作用对象包括煤中所有形态的硫.该实验结果显示硅酸盐细菌在脱硫研究中有潜在应用前景.     

Effects of Heavy Metal Contamination on Microbial Biomass and Community Structure in Soils

Theeco environmentalpollutioncausedbyminingdevelopmentisaworldwideproblem ,whichhasarousedever increasingattentionofscientists.Inadditiontovegetationdestructionanderosionofcultivatedlanddirectlycausedbyminingdevelopment,scientistshaveplacedmorefocusontheenvironmentalproblemsinducedbythereleaseofharmfulsubstances ( particularlyheavymetals) .Especiallyundersurfaceconditions,thepiled upminewastes (minetailings)undergoweatheringundertheactionofaseriesofgeochemicalfactorssuchasthemineralogyofmineta…     

城市纳污河流沉积物微生物群落结构特征

以南京市运粮河沉积物为研究对象,通过磷脂脂肪酸(PLFA)技术分析了不同水期城市纳污河流沉积物微生物群落结构特征。结果表明:在不同的水期运粮河沉积物微生物量出现了显著差异,温度是导致微生物量在丰、平、枯三期出现显著差异的主要因素(P<0.05);在相同水期,营养物质含量高的地方对应着高的微生物量;16:0 iso、17:0 anteiso、15:0 iso这几种PLFA所指示的革兰氏阳性菌(G+)是影响运粮河沉积物微生物群落构成的主要菌落,导致沉积物微生物群落结构出现显著差异的环境因素是水期;单不饱和/支链脂肪酸比值可以作为反映水环境系统整体营养水平的指标,在C/N比值升高时微生物会将单不饱和脂肪酸转变成环丙基或者饱和脂肪酸以适应新的环境;PLFA含量比[c(i15:0)+c(i17:0)]/[c(a15:0)+c(a17:0)]可以作为指示水环境碳素含量的标志。     

铀的微生物成矿作用实验研究进展

阐述了微生物成矿作用的基本概念、近年来铀的微生物成矿作用实验研究进展和研究成果;着重指出关于实验模拟微生物对成矿元素的吸附、迁移和还原富集能力的最新观点和思路,包括铀的微生物成矿作用的可能途径、参与成矿的方式、成矿作用机理及与此相应的实验模拟等,并提出铀的微生物、有机和无机综合成矿机理综合实验模拟的必要性。     

中国东部农耕区土壤微生物碳的分布及影响因素

对中国东部不同纬度带的6个地区的土壤微生物碳进行了研究。结果表明土壤微生物碳的分布受地理位置的影响较为明显:由北向南,东北地区的土壤微生物碳要高于其他地区。作为土壤有机质变化的灵敏度指标———微生物熵(微生物碳/总有机碳),在同一耕作方式下,其在不同地区的变化受土壤利用方式的影响较为明显:在连作系统下,菜地>粮地;而在轮作系统下,粮食-蔬菜轮作>蔬菜-蔬菜轮作。利用相关性分析寻求影响微生物碳分布的环境因素,结果表明,微生物碳(Micro-C)与土壤有机碳(TOC)、全氮(TN)、土壤含水率呈极显著正相关,而有机碳和全氮的分布主要受地理位置的影响。对不同土壤类型的微生物碳和微生物熵进行相关性分析,结果显示pH、年均温、含水率、TOC和TN是主要影响因素,关键影响因素因土壤类型不同而各异。     

Aquifer/aquitard interfaces: mixing zones that enhance biogeochemical reactions

Several important biogeochemical reactions are known to occur near the interface between aquifer and aquitard sediments. These reactions include O₂ reduction; denitrification; and Fe³⁺, SO₄ ^2–, and CO₂ (methanogenesis) reduction. In some settings, these reactions occur on the aquitard side of the interface as electron acceptors move from the aquifer into the electron-donor-enriched aquitard. In other settings, these reactions occur on the aquifer side of the interface as electron donors move from the aquitard into the electron-acceptor-enriched, or microorganism-enriched, aquifer. Thus, the aquifer/aquitard interface represents a mixing zone capable of supporting greater microbial activity than either hydrogeologic unit alone. The extent to which biogeochemical reactions proceed in the mixing zone and the width of the mixing zone depend on several factors, including the abundance and solubility of electron acceptors and donors on either side of the interface and the rate at which electron acceptors and donors react and move across the interface. Biogeochemical reactions near the aquifer/aquitard interface can have a substantial influence on the chemistry of water in aquifers and on the chemistry of sediments near the interface. Electronic Publication     

海洋天然气水合物勘查和识别新技术:地质微生物技术

当前国内外海洋天然气水合物勘查和评价发展趋势要求有更多具有精细探测和评价功能的技术,这给地质微生物水合物探测技术的研发和应用提出了需求和挑战。简要介绍了当前水合物成藏或沉积环境研究中所涉及的主要微生物类别及其主要关系,它们绝大多数是适应海底深部低温高压环境的厌氧极端生物。其中重要类群是为天然气提供气源的产甲烷古生菌、参与甲烷厌氧氧化过程的甲烷氧化古生菌和硫酸盐还原细菌。介绍了国内外几个地质微生物探测技术的实例,包括历史悠久的"微生物油气勘探"技术、近十年来发展起来的微生物计数法、群落结构和标志类别法;另外,对新露头角的微生物生物标志物法等其他方法也给予简要介绍。     

工艺矿物学近十年的主要进展

我国的工艺矿物学在过去十年中的重大进展主要表现在以下几方面:(1)矿物加工和冶金工艺矿物学的发展与应用;初步建立了矿物-生物浸矿机制和各类微生物冶金的制约因素,为生物选矿和冶金过程中工艺矿物学奠定了新的理论基础.(2)新的分析技术的发展及其应用使工艺矿物学开始从定性走向定量;探测和揭示了微生物在分子水平上与矿物表面相互作用和能量转换.这些研究将有助子了解微生物矿产开采和微生物选矿和冶金的控制因素的机制,为建立一个新的选冶工艺矿物学打下了深厚基础.(3)将矿物的晶体化学,矿物物理学,量子矿物学与工艺矿物学紧密结合,使这门应用学科不仅在选、冶、加工工艺等提取其中的某种有用元素,而且也促进了新兴的矿物材料和技术的发展.总之,在未来新的分析技术发展中,将被更广泛地用于研究矿物质,矿物-水界面和矿物-微生物界面,这不仅在新型的工艺矿物学发展中取得了好的成果,而且在环境矿物学,也有广泛的应用前景.     

Characterization of the Microbial Dolomite of the Upper Sinian Dengying Formation in the Hanyuan Area of Sichuan Province, China

The algal dolostone of the Upper Sinian Dengying Formation (corresponding to the Ediacaran system) in the Upper Yangtze Platform of China possesses a rich diversity of microorganisms and is an ideal site for the study of ancient microbial dolomite. We focused on algal dolostone and its microbial dolomite in the Hanyuan area of Sichuan Province, China. The macroscopic petrological features, microscopic morphology, texture characteristics of the fossil microorganisms and microbial dolomite, and geochemical characteristics were investigated. We found rich fossil microorganisms and microbial dolomites in the laminated, stromatolithic, uniform and clotted (algal) dolostones. The microorganisms present were mainly body fossils of cyanobacteria (including Renalcis, Girvanella, Nanococcus, and Epiphyton) and their trace fossils (including microbial mats (biofilms), algal traces, and spots). In addition, there was evidence of sulfate-reducing bacteria (SRB), moderately halophilic aerobic bacteria, and red algae. The microbial dolomites presented cryptocrystalline textures under polarizing microscope and nanometer-sized granular (including spherulitic and pene-cubical granular) and (sub) micron-sized sheet-like, irregular, spherical and ovoidal morphologies under scanning electron microscope (SEM). The microbial dolomites were formed by microbially induced mineralization in the intertidal zone and lagoon environments during the depositional and syngenetic stages and microbially influenced mineralization in the supratidal zone environment during the penecontemporaneous stage. The microbial metabolic activities and extracellular polymeric substances (EPS) determined the morphology and element composition of microbial dolomite. During the depositional and syngenetic stages, the metabolic activities of cyanobacteria and SRB were active and EPS, biofilms and microbial mats were well-developed. EPS provided a large number of nucleation sites. Accordingly, many nanometer-sized pene-cubical granular and (sub) micron-sized sheet-like microbial dolomites were formed. During the penecontemporaneous stage, SBR, cyanobacteria, and moderately halophilic aerobic bacteria were inactive. Furthermore, nucleation sites reduced significantly and were derived from both the EPS of surviving microorganisms and un-hydrolyzed EPS from dead microorganisms. Consequently the microbial dolomites present nanometer-sized spherulitic and micron-sized irregular, spherical, and ovoidal morphologies. Overall, the microbial dolomites evolved from nanometer-sized granular (including spherulitic and pene-cubical granular) dolomites to (sub) micron-sized sheet-like, irregular, spherical and ovoidal dolomites, and then to macroscopic laminated, stromatolithic, uniform, and clotted dolostones. These findings reveal the correlation between morphological evolution of microbial dolomite and microbial activities showing the complexity and diversity of mineral (dolomite)-microbe interactions, and providing new insight into microbial biomineralization and microbial dolomite in the Precambrian era.     

Controls on microbial activity and tidal flat evolution in Shark Bay,Western Australia

Microbial deposits at Shark Bay constitute a diverse living microbial carbonate system, developed in a semi‐arid, highly evaporative marine setting. Three tidal flats located in different embayments within the World Heritage area were investigated in order to compare microbial deposits and their Holocene evolution. The stressing conditions in the intertidal–subtidal environment have produced a microbial ecosystem that is trapping, binding and biologically inducing CaCO₃ precipitation, producing laminated stromatolites (tufted, smooth and colloform), non‐laminated thrombolitic forms (pustular) and cryptomicrobial non‐laminated forms (microbial pavement). A general shallowing‐upwards sedimentary cycle was recognized and correlated with Holocene sea‐level variations, where microbial deposits constitute the younger (2360 years bp ) and shallower sedimentary veneer. In addition, sediments have been documented with evidence of exposure during the Holocene, from 1040 to 940 ¹⁴C years bp , when sea‐level was apparently lower than present. Filamentous bacteria constitute the dominant group in the blister, tufted and smooth mat types, and coccus bacteria dominate the pustular, colloform and microbial pavement deposit types. In the subtidal environment within colloform and pavement structures, microbial communities coexist with organisms such as bivalves, serpulids, diatoms, green algae (Acetabularia), crustaceans, foraminifera and micro‐gastropods, which are responsible for exoskeleton supply and extensive bioturbation. The internal fabric of the microbial deposits is laminated, sub‐laminar, scalloped, irregular or clotted, depending on the amount of fine‐grained carbonate and the natural ability of microbial communities to trap and bind particles or induce carbonate precipitation. Nilemah tidal flat contains the thickest (1·3 m) and best‐developed microbial sedimentary system; its deposition pre‐dated the Rocky Point and Garden Point tidal flats, with the most positive isotope values for δ¹³C and δ¹⁸O, reflecting strong microbial activity in a highly evaporative environment. There is an evolutionary series preserved within the tidal flats reflecting relative ages and degree of salinity elevation.     

松辽盆地泰康隆起东翼杜20-3井区油气微生物勘探

采用油气微生物勘探技术对松辽盆地泰康隆起东翼杜20-3井区进行油气勘探分析。以微生物异常为基础,结合工区内现有的区域地质、钻井和测井等资料,并根据油气微生物异常的分布情况,明确了研究区的油气富集规律,同时完成了工区内石油微生物异常区的圈定。从本工区内的沉积相、反射层构造等深线的展布、以及与邻区的异常对比等方面入手,详尽地分析了工区内的油气远景,给出结论和勘探建议:该工区的油气远景较差,基本上为油异常区;工区内勘探程度较低,需要加强综合研究,确定含油层系,从而为勘探区块评价和探井井位设计提供依据,进一步认识整个研究工区的油气富集规律。     

Textured organic surfaces associated with the Ediacara biota in South Australia

The Ediacaran Period takes its name from the fossils of the Ediacara biota, which represent the first appearance of large and diverse assemblages of organisms in the fossil record. Although the global record of these distinctive body fossils is now well known, a previously unrecognized megascopic organic record of textured organic surfaces (TOS) occurs in the Ediacara biota. However, TOS is also a feature over a wider range of paleoenvironmental settings, where body fossils are unknown, in Ediacaran siliciclastic successions that have been studied in Australia, Namibia and western North America.Paleoecological analysis of successive bedding planes of strata from the late Ediacaran Rawnsley Quartzite in the Flinders Ranges of South Australia, reveals that TOS represent the most common organic features in bedding-surface assemblages of the Ediacara biota. The TOS consist of preserved, patterned assemblages of textured organic mats, fibers and simple tubular body fossils. Complex Ediacara body fossils while striking for their distinctive body plans, and dominating some of the beds, are relatively minor components of combined overall surface area. Many elements of TOS have previously been miss-diagnosed as trace fossils, which are in practice limited to two or at most three morphotypes that indicate the presence of Bilateria. Although TOS represent a simpler grade of organismic construction than discrete and more complex Ediacara body fossils, they were preserved in a similar manner. Marked variability in all components of the biota between successive surfaces suggests that Ediacara ecologies fluctuated at short intervals despite an apparently consistent sedimentary regime.     

地下水NO -3污染的微生物修复实验研究

随着农业的发展,尤其是化肥和农药的超量施用,产生了一系列的环境问题,已危及地下水的质量安全。大量的氮素没有被农作物吸收,经微生物硝化作用后,以硝态氮的形式进入土体和地下水。浅层地下水已普遍受到氮素不同程度的污染。本文以硝态氮污染为例,在实验室探索了硝态氮污染地下水微生物修复的实验方法,通过室内模拟含水层地下水静止条件和流动条件下,利用优选的菌群制剂和少量营养碳源,对试验区高含NO-3地下水的修复试验效果是显著的,去除率可达90%～100%。其作用还是持续的,静止条件下试验进行到256d时,其去除率仍达89 74%;流动条件下试验进行到112d时,试验主孔下游的观测孔3#、4#中的去除率也还有16 22%和27 26%。试验结果为野外现场原位微生物修复提供了技术支撑。     

微生物成因白云石研究进展

"白云岩问题"一直是沉积地质学研究的热点和难点之一,白云岩在我国和世界范围内都是重要的油气储层。因此,深入认识白云岩成因对于碳酸岩油气勘探具有重要参考意义。白云岩成因有多种解释模式,如萨布哈蒸发模式、渗透回流模式、埋藏调节模式、混合水模式、潮汐泵模式等。近几十年来,随着低温白云石研究的不断深入,微生物白云石模式作为一种新的成因模式被提出并不断被完善。本文回顾了微生物成因白云石的研究进展,总结了低温白云石形成的3个动力学障碍(镁离子的高水合能、硫酸根的存在、碳酸根离子的低浓度和低活度),简要介绍了微生物成因白云石模式的建立、微生物成因白云石的生长过程及发育特征,系统分析了微生物在白云石形成过程中的调节作用,指出微生物(如硫酸盐还原菌、古甲烷菌)的存在可以改变溶液中的离子平衡,进而有利地克服白云石形成过程中的动力学障碍,并列举了低温微生物成因白云石的氧同位素指标在古温度恢复和过去气候变化研究中的应用,最后对微生物成因白云石相关研究方向(如多学科交叉、新技术应用等)加以展望。对微生物成因白云石模式的深入认识,将为正确解释"白云岩问题"提供新的途径,也将为石油学家关心的白云岩储层问题提供新的理论基础和研究思路。     

Effect of humic acids on numbers and activities of micro-organisms within physiological groups

The incorporation of humic acid fractions in media designed for the enumeration of soil micro-organisms belonging to specific physiological groups was found to result for some groups in appreciably higher counts. It is suggested that by influencing the enzyme systems of certain micro-organisms, humic compounds may affect the range of substrates which they can utilize. The effect could have implications on the activity of organisms in environments in which humic substances are normally present, such as soils and natural waters.     

Relationship between Microbial Activity and the Formation of Polymetallic Concretions in the Central Pacific Ocean

Using the concept of the interactive water rock- microbe system of ocean floor, the microbialmineralization of ocean-floor polymetallic concretions in the central Pacific Ocean has been studied for the firsttime. Through the correlation and study of the microbial activity and formation mechanism of polymetallicconcretions, the microbial and chemical processes for. transforming mineralizing materials and the observationand determination of the concentration of mineralizing material in the system and the variation ofenvironmental parameters, this paper reveals the reaction rate and evolutionary direction of mineralizing com-ponents caused by microbial activity, expounds the microbial mineralization mechanism and formation modelof polymetallic concretions from the angle of microbial geochemical action, and suggests a threefold division ofthe microbial mineralization stages     

Geochemical and Microbiological Analysis of Sambe Hot Springs,Shimane Prefecture,Japan

Microbiological contribution to the formation of the manganese deposits in Sambe hot springs, Shimane, was investigated in combination with water chemistry, characterization of sediments and microbial community structure. Analysis of bacterial and fungal community structure based on DNA extracted from a Mn‐oxidizing enrichment culture indicated close matches with Pseudomonas putida, Phoma sp. and Plectosphaerella cucumerina, all Mn‐oxidizing microorganisms. These sediments were poorly crystalline and formed at neutral pH values, which is characteristic of biogenic precipitates. The EPMA results demonstrated a positive correlation between Mn and Ba contents in well‐crystalline Mn oxide grains. Substantial Ba contents were observed inside Mn oxide grains. These findings indicated that Ba contents in sediments are influenced by not only aqueous Ba²⁺ concentrations but also crystallinity of biogenic birnessite. Barium would be incorporated in birnessite during biomineralization.     

鄂尔多斯盆地东北部奥陶系马五1+2微生物碳酸盐岩沉积特征及储集意义

基于岩芯、薄片及物性资料,研究鄂尔多斯盆地东北部奥陶系马五₁₊₂微生物岩沉积特征及其油气储集意义。研究区发育有不同规模的由蓝细菌群落构成的微生物碳酸盐岩建造,由叠层石、菌纹层白云岩、蓝细菌凝块岩以及菌黏结颗粒岩构成了藻坪和微生物丘建造。微生物丘纵向上建造规模较小,单旋回厚度一般小于1 m,发育于潮下高能环境,并由花斑状砂屑云岩、蓝细菌凝块岩、菌黏结砂屑云岩、菌纹层白云岩构成了丘基-丘核-丘坪的向上变浅序列,也常与颗粒滩相伴生构成丘滩复合体。其中,发育于丘核部位的蓝细菌凝块岩和菌黏结砂屑云岩中窗格孔和粒间孔发育,表现为中孔低渗特征,可作为盆地东北部的储集岩之一。