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1.
硅酸盐矿物分解细菌Bacillus globisporus Q12与云母矿物相互作用的研究 总被引：2，自引：0，他引：2
土壤矿物与微生物相互作用对土壤中一系列生态过程产生重要影响。本文通过对培养液进行K、Si、Fe、Al等元素分析,测定了菌株生长与代谢产物,结合扫描电镜和透射电镜的观察,研究了钾矿物表生硅酸盐矿物分解细菌Bacillus globis-porusQ12菌株与云母矿物(黑云母和白云母)的相互作用规律。结果表明,不同的云母矿物对B.globisporusQ12菌株的生长与代谢有不同影响;与白云母相比,黑云母更适合B.globisporusQ12菌株的生长与酸性代谢产物(如有机酸等)的合成;供试菌株能促进黑云母和白云母矿物中K、Si、Fe、Al等元素的释放。扫描电镜、透射电镜观察与能谱分析发现,B.globisporusQ12菌株能在云母矿物表面定殖,加速云母矿物的风化;菌体自身也能吸附培养液中离子和矿物碎片而形成新的矿物。 相似文献
2.
选用一株从铝土矿样表面分离的硅酸盐细菌,研究了该菌株对矿物种类与组成复杂的铝土矿的风化作用.通过摇瓶培养,使硅酸盐细菌在培养液中与矿物颗粒发生相互作用,再测定不同发酵时间上清液中主要杂质元素的含量,并对细菌作用不同时间后的铝土矿进行电镜观察和电子能谱扫描及X射线衍射分析.结果表明,随着培养时间的延长,发酵液中形成了明显的菌体-矿物复合体,细菌对矿物表面产生了溶蚀作用;细菌对不同晶体结构的矿物具有选择性破坏作用,层状结构的高岭石、伊利石比架状结构的石英等矿物更容易风化风化;该菌株可以释放铝土矿中的铝、硅、铁、钙、钾等元素到培养液中,矿物表面的钙元素百分含量从19.44降低至1.91,铁、钾从1.70、1.28降低至微量.结合矿物学与微生物相关知识,初步探讨了细菌与矿物界面之间的相互作用及矿物的微生物风化机制. 相似文献
3.
为了探讨细菌作用下碳酸盐矿物的形成机理,本文对分离自土壤的一株柠檬酸杆菌GW-M菌株进行了为期165d的培养 实验。利用X-射线衍射技术对沉淀物的矿物成分进行了测定,利用扫描电子显微镜对沉淀物的形态进行了系统的观察。结果 表明,GW-M菌株诱导形成的碳酸盐矿物（方解石和单水碳钙石）具有多种形态共存并以球状为主的特点,而无菌对照实验产 物中的矿物形态则比较单一。在GW-M菌株的作用下,通过以下三条途径均可能形成球状矿物：（1）单个哑铃→两端生长→ 球;（2）两个交叉的哑铃→两个哑铃的两端各自生长→球;（3）三个交叉的哑铃→三个哑铃的两端各自生长→球。 相似文献
4.
为了探究培养方式（振荡和静置） 对细菌诱导形成的碳酸盐矿物种类和形态的影响,本文在B4培养基中分别对蜡状
芽孢杆菌（GW-1菌株）、赖氨酸芽孢杆菌（GW-2菌株） 和微杆菌（GW-3菌株） 三种细菌进行了为期40天的振荡培养实验
及相应的无菌对照实验,重点利用X-射线衍射仪和扫描电子显微镜分别对矿物成分和形态进行了测定和观察,并将观测结
果与静置条件下的结果进行了对比。结果表明：（1） 三种细菌均具有促进碳酸盐矿物沉淀的功能,但能力有所不同,从大
到小的顺序为GW-2＞GW-1＞GW-3;（2） 在振荡和静置两种培养方式下,GW-1和GW-2菌株诱导形成的矿物均为方解石,
而GW-3菌株诱导形成的矿物均为球霰石。这说明细菌种类是影响矿物相的重要因素,培养方式对矿物相无明显的影响;
（3） 对于GW-1和GW-2菌株,其在振荡培养条件下诱导形成的矿物形态呈现多样化,而在静置培养条件下形成的矿物形态
则比较单一。对于GW-3菌株,其诱导形成的矿物均为球形,与培养方式无关。 相似文献
5.
利用铝硅酸盐矿物为能源的硅酸盐细菌选择性分离培养基,对从鄱阳湖地区不同性质土壤中筛选出了 18 株拟溶硅菌 种进行实验。通过对其产酸、产多糖、形成细菌-矿物复合体与溶硅能力的测定,定向筛选出P04与P17两株环状芽孢杆菌, 并以中国普通微生物菌种保藏中心环状芽孢杆菌 CGMCC1.0153(编号为 P19)(Bacillus circulans)为参照菌株,对其表型形态、 生理生化特性及脱硅效果进行了研究。结果表明:与其它菌种比较,这两株菌种具有较强的产酸、产多糖与溶硅能力,在 培养基中能形成明显的细菌-矿物复合体;通过与模式菌株的表型形态与生理生化特征及16S rRNA基因鉴定结果比较,可 认为 P04 与 P17 是环状芽孢杆菌;在实验条件下,P04,P17 与 P19 对铝土矿均有一定的脱硅能力,浸矿 12d 后,浸出上清液 中SiO2最大含量分别为54.26,42.78,47.98 mg/L,铝土矿的A/S从浸出前的5.17分别提高到10.99,7.61和8.90。表明具有 较强产酸、产多糖能力并能形成明显细菌 - 矿物复合体的环状芽孢杆菌的脱硅能力较强。 相似文献
6.
微生物影响硅酸盐矿物风化作用的模拟试验 总被引：18，自引：1，他引：17
研究了硅酸盐细菌对矿物的风化作用。选用土壤中常见的钾长石、伊利石等矿物作为细菌风化作用的对象,通过在含有矿物颗粒的无氮培养基中培养硅酸盐细菌,使其在培养液中与矿物颗粒发生相互作用,再取样并处理后进行电镜观察和X-射线衍射分析。电镜观察结果表明细菌对矿物试样表面确实发生了溶蚀作用,被细菌作用后的矿粉,颗粒浑圆,边缘模糊不清,表面呈凹凸不平状,矿物颗粒被大量的菌体物质所覆盖。用X-射线衍射分析检测到细菌对具不同晶体结构矿物的“选择性”破坏作用,在有多种矿物同时存在的情况下,细菌对较易分解的矿物破坏作用速度较快。结合矿物学与微生物学相关知识,初步分析了细菌培养液中细菌与矿物界面之间的相互作用以及土壤生态系统中矿物的生物风化作用过程。 相似文献
7.
8.
航空高光谱识别的高、中、低铝绢云母矿物成因学研究 总被引：2，自引：0，他引：2
国内外学者在航空高光谱矿物填图时,根据Al-OH光谱特征吸收波长位置不同将浅色云母类矿物分为2~3类,分别命名为高铝绢云母、中铝绢云母、低铝绢云母,但对它们的成因特点却只有零星的讨论,没有比较系统的有针对性的研究。本文在新疆雪米斯坦铀多金属成矿带获取CASI/SASI航空高光谱数据,并开展矿物填图的基础上,针对高铝绢云母、中铝绢云母、低铝绢云母等三种矿物的成因学专门开展了比较系统的研究。采用的方法主要是在开展详细的野外地质观察、采样的基础上,对采集的上述三类矿物蚀变岩样品进行详细的室内光谱测量、Al-OH吸收波长位置统计、显微薄片观察、全岩X衍射分析、粘土X衍射分析等研究,并结流体成矿理论和已有矿物成因学知识,进行了详细深入的分析讨论。研究表明,高铝绢云母蚀变岩蚀变强烈,云母类蚀变矿物以绢云母、伊利石为主,且主要与叶腊石和微晶石英等矿物伴生,而低铝绢云母蚀变岩蚀变强度中等,以伊利石、伊蒙混层为主,绿泥石增加,主要与方解石、浊沸石等矿物伴生;高铝绢云母蚀变岩具有相对高的石英含量和粘土矿物总量,具有相对较低的钾长石、斜长石以及方解石含量;低铝绢云母蚀变岩则具有相对较低的石英和粘土含量,具有相对较高的斜长石、钾长石和方解石含量。通过深入分析讨论,本文提出了在研究区航空高光谱识别的高铝绢云母形成于相对高温、偏酸性的热液流体环境,低铝形成于相对低温、偏碱性的热液流体环境。这一新认识对航空高光谱遥感矿物填图结果的深入应用和深层次找矿信息反演具有重要意义。 相似文献
9.
土壤微生物与矿物的吸附作用在矿物风化过程中具有重要的意义。为了优化细菌在矿物表面吸附量的测定方法,本文以胶质芽孢杆菌和蒙脱石、伊利石、高岭石为实验材料,对吸附在矿物表面的细菌数量的测定方法进行了研究。结果表明,利用茚三酮作为显色剂测定细菌蛋白质含量的方法可以获得可靠的细菌数量;以2000rpm转数离心10min可以有效地将矿物-细菌复合体与游离态细菌、矿物分开;3种矿物对胶质芽孢杆菌的吸附能力大小顺序为:蒙脱石伊利石高岭石;矿物的比表面积、沉淀速率和表面所带电荷数量以及细菌细胞活性是影响吸附量的主要因素;黏土矿物与细菌之间的吸附作用力主要来自阳离子桥。 相似文献
10.
胶质芽孢杆菌的胞外分泌物与细菌的解钾作用 总被引：4，自引：0，他引：4
研究了胶质芽孢杆菌(Bacillus mucilaginosus)KO1菌株在不同培养条件下,其荚膜多糖含量随时间的变化以及菌株在有氮、无氮培养基中的解钾作用。结果表明,尽管该菌在无氮培养条件下的菌体数量远小于有氮培养条件,但无氮培养条件下所提取的细菌多糖多于在有氮条件下培养所提取的细菌多糖;胶质芽孢杆菌在以添加钾长石粉或黑云母粉制作的无氮培养基中生长可形成大量多糖,采用丙酮法进行细菌培养液多糖提取,发现细菌培养的第3天所提多糖含量最高;胶质芽孢杆菌在以添加钾长石粉或黑云母粉制作的有氮培养基中生长亦可形成较多的多糖,且在细菌培养的第4天所提多糖含量最高;胶质芽孢杆菌在有氮条件下对含钾矿物的释钾率高于在无氮条件下的释钾率,这可能与该菌在有氮条件下生长更快、可产生较多菌体细胞有关。分析表明,该菌在有氮条件下产生的胞外糖蛋白高于在无氮条件下产生的胞外糖蛋白,蛋白质在细菌分解转化含钾矿物过程中可能发挥重要作用。 相似文献
11.
MUKESH R K MANHAS A K TRIPATHI A K RAINA M K GUPTA S K KAMBOJ 《Journal of Earth System Science》2011,120(1):123-144
The peteromineralogical characterization of the soil was carried out for the 12 soil profiles exposed in the Shorea robusta dominated forests of the Siwalik forest division, Dehradun. The quartz was observed as the dominating light mineral fraction
(64–80%) in all the profiles studied. Biotite, hornblende, zircon, tourmaline, rutile and opaques comprising of iron minerals
constituted the heavy mineral fraction (20%). The mineralogy of both the sand and clay fractions revealed a mixed mineralogy.
The clay minerals in the order of their dominance were vermiculite, illite, kaolinite and mixed layer minerals. The presence
of vermiculite and illite in appreciable quantities indicates that these were synthesized from the K-rich soil solution, as
orthoclase and micas were present in significant quantities in the sand minerals. The mineral suites identified in the study
shows that the geological, climatological and topographical factors of the region collectively played a dominant role in their
formation and transformation. After critical appraisal of the results, it may be deduced that the mineralogical composition,
physicochemical properties and total elemental analysis of the soils do not show any deficiency of the bases and other plant
nutrients in general. The inherent fertility of the soil is good as indicated by the sand and clay mineralogy of the soil
and the biotite and feldspar together with the mica is an important source of nutrients for the vegetation in the soils of
the Doon valley. 相似文献
12.
应用X射线衍射-扫描电镜-光学显微镜鉴定黑龙江石墨尾矿中的绢云母 总被引：2，自引：2，他引：0
石墨尾矿作为一类二次资源,当云母类矿物的含量在10%以上时,具有回收利用价值。黑龙江某地石墨尾矿中含有10%以上的云母类矿物,但其细度(500~800目)低于常规的云母矿,本文采用X射线衍射(XRD)分析矿物组成,再结合化学分析、扫描电镜-能谱、光学显微镜与纯矿物进行对比,由此鉴定云母类矿物种属。XRD研究初步表明石墨尾矿含有的云母族矿物属于白云母亚类或黑云母亚类。扫描电镜分析表明尾矿中的云母矿物与纯绢云母矿物均以片状和鳞片状为主要存在形态,而纯黑云母主要以片状形式存在。尾矿的Si O2含量为5%~13%,Al2O3含量为4%~8%,与纯绢云母接近。光学显微镜鉴定显示在正交偏光下石墨尾矿中的云母颜色和纯绢云母类似,而与纯黑云母截然不同。综合以上结果最终可确定该地石墨尾矿中的云母族矿物为白云母亚类中的绢云母。本研究为后续石墨尾矿的选矿工艺奠定了基础,也可应用于类似细度绢云母的鉴定。 相似文献
13.
Susan L. Brantley Laura J. Liermann Ariel Anbar Jane Barling 《Geochimica et cosmochimica acta》2004,68(15):3189-3204
Fe released into solution is isotopically lighter (enriched in the lighter isotope) than hornblende starting material when dissolution occurs in the presence of the siderophore desferrioxamine mesylate (DFAM). In contrast, Fe released from goethite dissolving in the presence of DFAM is isotopically unchanged. Furthermore, Δ56Fesolution-hornblende for Fe released to solution in the presence of ligands varies with the affinity of the ligand for Fe. The extent of isotopic fractionation of Fe released from hornblende also increases when experiments are agitated continuously. The Fe isotope fractionation observed during hornblende dissolution with organic ligands is attributed predominantly to retention of 56Fe in an altered surface layer, while the lack of isotopic fractionation during goethite dissolution in DFAM is consistent with the lack of an altered layer. When a siderophore-producing soil bacterium is added to the system (without added organic ligands), Fe released to solution from both hornblende and goethite differs isotopically from Fe in the bulk mineral: Δ56Fesolution-starting material = −0.56 ± 0.19 (hornblende) and −1.44 ± 0.16 (goethite). Increased isotopic fractionation is attributed in this case to the fact that as bacterial respiration depletes the system in oxygen and aqueous Fe is reduced, equilibration between aqueous ferrous and ferric iron creates a pool of isotopically heavy ferric iron that is assimilated by bacterial cells. Adsorption of isotopically heavy ferrous iron (Fe(II) enriched in the heavier isotope) or precipitation of isotopically heavy Fe minerals may also contribute to observed fractionations.To test whether these Fe isotope signatures are recorded in natural systems, we also investigated extractions of samples of soils from which the bacteria were isolated. These extractions show variability in the isotopic signatures of exchangeable Fe and Fe oxyhydroxide fractions from one soil sample to another, but exchangeable Fe is observed to be lighter than Fe in soil Fe oxyhydroxides and hornblende. This observation is consistent with isotopically light Fe-organic complexes in soil pore water derived from the Fe-silicate starting materials in the presence of growing microorganisms, as documented in experiments reported here. The contributions from phenomena including organic ligand-promoted nonstoichiometric dissolution of Fe silicates, uptake of ferric iron by organisms, adsorption of isotopically heavy ferrous iron, and precipitation of iron minerals should create complex isotopic signatures in soils. Better understanding of these processes and the timescales over which they contribute to fractionation is needed. 相似文献
14.
The transformation of clastogenic muscovite and biotite from the Tyumen superdeep well was studied with the SEM and microprobe techniques. It was shown that under conditions of anchimetamorphism (metagenesis), the white mica becomes unstable and may be replaced by several newly formed minerals. In particular, the brammallite, a sodic analogue of illite, is formed at the expense of sodic component of muscovite. The chloritization of mica provokes the removal of excess silica, which is present in the anchizone as a readily soluble in water modification rather than quartz. The release of excess silica as a result of clastogenic mica destruction may be a source of rock silification. As follows from the review of experimental data on silica solubility, the replacement of many silicate minerals leads to the formation of excess silica. This process can be highly extensive during the breakdown of clastogenic minerals. 相似文献
15.
Weathering experiments using biotite and phlogopite in the presence of bacteria were conducted to better understand biotic dissolution kinetics and processes (proton- and ligand-promoted dissolution) under aerobic conditions. Miniature batch reactors (300 μl in microplate wells) were used at 24 °C for 3 days with and without bacterial strains. Abiotic experiments were performed with organic and nitric acids in order to calibrate the biotite-phlogopite chemical dissolution. An empirical model was used to fit the pH dependence for iron release rate (rFe) considering the influence of both protons and ligands from acidic to neutral conditions (pH ranging from 3 to 7): rFe=kH(aH+)m+kL(aL)1 where k is the apparent rate constant, aH+ and aL are the activities of protons and ligands, and m and l are the reaction orders. For both minerals in most cases at a given pH, the iron release rates in the presence of bacteria were in good agreement with rates determined by the chemical model and could be explained by a combination of proton- and ligand-promoted processes. Bacteria affect mineral dissolution and iron release rates through the quantities and nature of the organic acids they produce. Three domains were differentiated and proposed as biochemical models of mica dissolution: (1) below pH 3, only proton-promoted dissolution occurred, (2) in weakly acidic solutions both ligand- and proton-promoted mechanisms were involved, and (3) iron immobilization occured, at pH values greater than 4 for biotite and greater than 5 for phlogopite. This model allows us to distinguish the “weathering pattern phenotypes” of strains. Bacteria that are isolated from horizons poor in carbon appear more efficient at weathering micas than bacterial strains isolated from environments rich in carbon. Moreover, our results suggest that the mineral could exert a control on the release of organic acids and the “weathering pattern phenotypes” of bacteria. 相似文献
16.
稀有金属铌钽在我国华南存在多时代成矿特征,前人对其最晚成矿期晚白垩世成矿事件报道较少。本文以浙东南的吴小垟铌矿床为研究对象,结合野外调查、岩石学、矿物原位微区分析和同位素年代学等研究,确定矿床铌成矿岩体为细粒黑云母花岗岩,成岩成矿年龄分别为89.2±0.8 Ma和86.5±1.0 Ma,揭示了该区存在晚白垩世花岗岩侵位及其相关铌成矿事件。铌除了以独立矿物的形式赋存在铌铁矿、铌铁金红石、铅烧绿石中,还有部分铌赋存于黑云母中。在岩浆-热液作用下,云母类型发生了从铁云母→黑鳞云母→铁锂云母的变化。铁云母Nb含量最高可达1253×10-6,黑鳞云母-铁锂云母铌含量最高至794×10-6,黑云母极度富铌的特征,指示该花岗岩具有非常好的铌找矿潜力,富铌黑云母可以作为一种铌钽找矿指示性矿物。综合上述矿物学特征,得出吴小垟矿床存在两阶段铌成矿事件:岩浆期原生铌铁矿族矿物、原生富铌黑云母和铌铁金红石的形成;以及后期热液作用下铌从岩浆和原生含铌矿物中迁移出形成次生的含铌氧化物。 相似文献
17.
Jennyfer Miot Karim Benzerara Andreas Kappler Martin Obst Fériel Skouri-Panet Nicole Posth Gordon E. Brown Jr. François Guyot 《Geochimica et cosmochimica acta》2009,73(3):696-1446
Minerals formed by bio-oxidation of ferrous iron (Fe(II)) at neutral pH, their association with bacterial ultrastructures as well as their impact on the metabolism of iron-oxidizing bacteria remain poorly understood. Here, we investigated iron biomineralization by the anaerobic nitrate-dependent iron-oxidizing bacterium Acidovorax sp. strain BoFeN1 in the presence of dissolved Fe(II) using electron microscopy and Scanning Transmission X-ray Microscopy (STXM). All detected minerals consisted mainly of amorphous iron phosphates, but based on their morphology and localization, three types of precipitates could be discriminated: (1) mineralized filaments at distance from the cells, (2) globules of 100 ± 25 nm in diameter, at the cell surface and (3) a 40-nm thick mineralized layer within the periplasm. All of those phases were shown to be intimately associated with organic molecules. Periplasmic encrustation was accompanied by an accumulation of protein moieties. In the same way, exopolysaccharides were associated with the extracellular mineralized filaments. The evolution of cell encrustation was followed by TEM over the time course of a culture: cell encrustation proceeded progressively, with rapid precipitation in the periplasm (in a few tens of minutes), followed by the formation of surface-bound globules. Moreover, we frequently observed an asymmetric mineral thickening at the cell poles. In parallel, the evolution of iron oxidation was quantified by STXM: iron both contained in the bacteria and in the extracellular precipitates reached complete oxidation within 6 days. While a progressive oxidation of Fe in the bacteria and in the medium could be observed, spatial redox (oxido-reduction state) heterogeneities were detected at the cell poles and in the extracellular precipitates after 1 day. All these findings provide new information to further the understanding of molecular processes involved in iron biomineralization by anaerobic iron-oxidizing bacteria and offer potential signatures of those metabolisms that can be looked for in the geological record. 相似文献
18.
The key role of mica during igneous concentration of tantalum 总被引：2，自引：0，他引：2
Aleksandr Stepanov John A. Mavrogenes Sebastien Meffre Paul Davidson 《Contributions to Mineralogy and Petrology》2014,167(6):1-8
Igneous rocks with high Ta concentrations share a number of similarities such as high Ta/Nb, low Ti, LREE and Zr concentrations and granitic compositions. These features can be traced through fractionated granitic series. Formation of Ta-rich melts begins with anatexis in the presence of residual biotite, followed by magmatic crystallization of biotite and muscovite. Crystallization of biotite and muscovite increases Ta/Nb and reduces the Ti content of the melt. Titanium-bearing oxides such as rutile and titanite are enriched in Ta and have the potential to deplete Ta at early stages of fractionation. However, mica crystallization suppresses their saturation and allows Ta to increase in the melt. Saturation with respect to Ta and Nb minerals occurs at the latest stages of magmatic crystallization, and columbite can originate from recrystallization of mica. We propose a model for prediction of intrusion fertility for Ta. 相似文献
19.
河北省平山县阜平群是一套高角闪岩相岩石。根据宏观现象，某些地段曾经历过深熔作用过程。深熔效应以小觉地区的夕线石钾长浅粒岩最为典型。通过电子显微镜观测确认，所研究的夕线石钾长浅粒岩经受了深熔作用的改造，具有丰富而显著的微区矿物学标志。主要表现为前存矿物，如钾长石、条纹长石、石英、钠长石、黑云母和磁铁矿等，不同程度地被熔蚀，主要组成元素发生迁移和重组，沿矿物的解理、裂隙及粒间形成夕线石、石英、云母、长石、金红石等再结晶相。在深熔过程中，元素的迁移有两种可能形式：①选择性地从前存矿物晶格中移出；②通过前存矿物的熔融。Fe、Ti等元素从黑云母中移出，形成再结晶磁铁矿和金红石；Si、AI等元素则从黑云母和长石中移出，形成夕线石和再结晶石英。 相似文献