西藏搭格架铯硅华区热泉高温菌株的分离及特征研究

从西藏搭格架铯硅华矿床区热泉中分离培养高温菌T4-1,并进行了格兰氏染色、显微镜观察、室内温度实验、16SrRNA基因分析等。结果表明,T4-1为杆状菌,格兰氏染色阳性,其生长范围为45~80℃,最适生长温度70℃。16SrRNA基因分析结果表明,该菌株属于地芽孢杆菌属(Geobacillus),在发育树上,T4-1菌株与高温烷烃地芽孢杆菌(Geobacillus the rmoleovorans)非常近。本研究为进一步开展西藏高温微生物资源以及微生物参与成矿作用的研究提供了首例。     

十红滩铀矿床中微生物种类多样性及生态分布规律的研究

利用生物学方法对新疆十红滩砂岩型铀矿各亚带矿石中参与C、N、S、Fe、O等元素循环的主要微生物菌群进行了研究.结果表明:在铀矿床中赋存着硫酸盐还原菌(SRB)、铁细菌(IB)、硫杆菌、硝化细菌、亚硝化细菌、反硝化细菌、芽孢菌等各类细菌.其中sRB种类较多,主要为脱硫弧菌属、脱硫肠状菌属、脱磺单胞菌属、脱硫杆菌性等.IB主要为鞘铁菌属、球衣菌属、瑙曼氏菌属和赭菌属.硫杆菌包括氧化硫硫杆菌、氧化亚铁硫杆菌、排硫硫杆菌、脱氮硫杆菌.硝化细菌主要为硝化杆菌属.亚硝化细菌主要为亚硝化单孢菌属.异养反硝化细菌为施氏假单胞菌和类鼻疽假单胞菌,自养反硝化细菌为脱氮硫杆菌.芽孢杆菌包括巨大芽孢杆菌、蜡状芽孢杆菌、侧孢芽孢杆菌、蜂房芽孢杆菌、球形芽孢杆菌.实验证明:各类细菌的种类和数量在铀矿床的空间分布上存在着一定的规律性对铀矿床的地球化学分带性具有一定的指示作用.     

漠河盆地科学钻探井MK-1地下冷环境中嗜热微生物的多样性分析

在漠河盆地科学钻探井MK-1地下110m冷环境样品中发现大量嗜热微生物存在的证据,针对这些冷环境中的嗜热菌进行了克隆文库分析和分离培养,分别用细菌和古菌16SrDNA引物PCR扩增.结果表明:未发现古菌16SrDNA存在,而嗜热细菌与栖热菌属(Thermus),地芽孢杆菌属(Geoba-cillus)和厌氧芽孢杆菌属(Anoxybacillus)有较近的亲缘关系,通过分离培养分离出3种地芽孢杆菌属(Geobacillus)的细菌,其相似度均为100%.嗜热微生物多存在于地下温暖有机质丰富的生态系统中,了解它们的来源、分布机制及其多样性对于能源和资源的寻找在一定程度上具有指示意义.     

金矿化指示菌的分子生物学鉴定

近年来, 土壤微生物蜡样芽孢杆菌(Bacillus cereus)芽孢计数对下伏金矿化的指示作用已被不同国家的地质工作者所证实, 但由于鉴别手段的限制, 对金矿化指示菌株的鉴定一直停留在传统的微生物分类鉴定上, 本研究将分子生物学的技术引入到金矿化指示菌株的鉴定中, 从而将微生物找矿中的微生物鉴定手段提高到分子水平.从湖北省嘉鱼县蛇屋山金矿区分离到的矿化指示菌株中随机挑取2株菌Y1和Y2, PCR扩增并测定其16SrDNA和16S-23SrDNA区间序列.经系统发育和生理生化试验综合分析, 表明Y1为蕈状芽孢杆菌(B.mycoides), Y2为蜡样芽孢杆菌, 两者都属于蜡样芽孢杆菌群, 证明蜡样芽孢杆菌群是金矿化指示菌, 同时也证明了传统微生物找矿法利用选择性培养基对蜡样芽孢杆菌群菌芽孢计数方法的可靠性和利用分子生物学技术进行采矿的可行性.菌株16SrDNA和16S-23SrDNA区间核苷酸序列的确定也为下一步微生物找矿中的基因探针试剂盒的制作奠定了基础.      

川西北某铀矿区微生物分布规律及核素固化研究

为了更好的发挥微生物在放射性污染环境中的环境净化作用,本研究选择川西北某铀矿区为研究对象,利用生物学方法研究其中两个代表性铀废矿石堆中的微生物多样性及其在放射性污染环境中的分布规律。结果表明:在该铀矿区中主要赋存着细菌、放线菌及霉菌三种菌,其中以细菌占绝对优势;对优势微生物——细菌分离鉴定获得3种优势菌株,鉴定结果为玫瑰色库克菌(Kocuria rosea strain)、短杆菌(Brevibacteriumsanguinis)和枯草芽孢杆菌(Bacillus subilis/atropheaus),研究认为玫瑰色库克菌(Kocuria rosea strain)在当地的放射性核素耐受性最好。     

铝土矿脱硅微生物的定向筛选及脱硅性能

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。     

胶质芽孢杆菌的胞外分泌物与细菌的解钾作用

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。     

层间氧化带砂岩型铀矿床微生物地球化学特征及与铀成矿的关系研究——以吐鲁番-哈密盆地十红滩铀矿床为例

通过样品采集、细菌培养和鉴定等,首次在中国大型的十红滩层间氧化带砂岩型铀矿床容矿层中发现不同种群的细菌。氧化带主要分布铁细菌、硫杆菌、硝化菌等好氧菌,矿石带主要分布厌氧的硫酸盐还原菌,其种类和数量上具明显的生物地球化学分带性,并与岩石的地球化学分带性一致。首次利用容矿层的硫酸盐还原菌在室内进行了硫酸盐还原试验。根据细菌的代谢特征,结合硫酸盐还原菌还原试验,分析了细菌在层间氧化带形成、铀氧化迁移和还原成矿过程中的作用。     

海南红树林湿地可培养硫酸盐还原菌的垂直分布特征研究

利用厌氧微生物分离技术,对深度为1.2 m 的海南红树林湿地沉积物钻孔样品进行了分离培养,共获得11 株 厌氧sulfate-reducing bacteria（SRB） 菌株。经显微观察和16S rDNA序列分析,可归纳为6个属,其中已经报道有芽孢杆菌 属（Bacillus）、弧菌属（Vibrio） 和梭状芽胞杆菌属（Clostridium）,另外3个属分别为伯克霍尔德菌属（Burkholderia）、希瓦氏菌属（Shewanella） 和海杆菌属（Marinobacterium）。不同属的细菌对硫酸盐还原的速率最低为14.71%,最高可达 56.78%,并且以上6属11株菌都能将+6价的硫还原生成-2价硫,并与培养基中的Fe2+结合生成黑色FeS沉淀,而这些无定 形FeS沉淀是生成黄铁矿的前体。红树林湿地SRB种群数量随沉积物深度的增加而降低,结合沉积物的地球化学分析测试 结果表明,表层（0 cm） 水界面的沉积物由于处于氧化-还原界面,氧气的周期性输入在一定程度上抑制了SRB的生长;随着 深度增加（10~40 cm）,充足的有机质、偏中性的pH值以及厌氧环境的增强,使得SRB种类和数量明显增加;而60 cm以下 沉积物中因TOC含量降低,减少了微生物可利用的碳源,pH值明显降低,Na+和Ca2+离子浓度明显增加,这些因素都抑制了 SRB的生长,使得深部沉积物中SRB的种类和数量显著减少。     

地衣芽孢杆菌对亚硒酸盐的还原

利用高硒碳质泥岩中筛选出的地衣芽孢杆菌(Bacillus licheniformi),研究了该菌对亚硒酸盐硒的耐受与还原行为。结果表明,液体培养基(YEG)中,它能耐受320 mM亚硒酸盐硒的浓度,耐受硒酸盐硒的浓度可高达1000 mM。然而,高浓度的亚硒酸盐硒对它的生长有明显的抑制作用。在有氧和厌氧的环境中,地衣芽孢杆菌均能还原亚硒酸盐中的硒:将四价硒还原为纳米球状的元素硒颗粒,使其分布在菌体的周边和细胞内。在含5 mM亚硒酸钠的液体培养基中,还原亚硒酸钠硒成为元素硒的平均效率约为42%。地衣芽孢杆菌在生存环境无严格要求的条件下,其还原亚硒酸盐硒形成纳米元素硒颗粒的现象,是研究生物合成低毒的纳米活性元素硒和生物修复硒污染技术的基础,也为硒的微生物矿化过程提供了契机。     

黑潮源区沉积物微生物多样性初步研究

从黑潮源区采集上层沉积物,进行DNA提取,以细菌和古菌的16S rDNA通用引物PCR扩增黑潮源区沉积物中细菌和古菌群落的16S rDNA,并构建细菌和古菌的16S rDNA文库,经限制性片段长度多态性分析(Restriction Fragment Length Polymorphism,RFLP),DNA序列测定和系统发育分析,对黑潮源区表层沉积物的细菌和古菌多样性进行了研究。研究结果表明:黑潮源区细菌包括了变形杆菌(Proteobacteria)、酸杆菌(Acidbacterium)、浮霉菌(Planctanycene)、疣微菌(Verrucomicro-bia)和Candidate division OP8和拟杆菌(Bacteroidetes)共6个类群,其中变形杆菌是优势类群。古菌包括了泉古菌(Crenarchaeota)和广古菌(Euryarchaeota),其中泉古菌占优势;泉古菌包括MCG、C3、MBGA和MGI 4个类群,而广古菌包括SAGMEG、MBGE和MEG 3个类群,其中MBGE是优势类群。     

Solubilization of potassium containing minerals by high temperature resistant <Emphasis Type="Italic">Streptomyces</Emphasis> sp. isolated from earthworm’s gut

A potassium solubilizing bacterial strain designated EGT, which is tolerant of high temperature, was isolated from an earthworm’s gut to obtain a bacterium that can weather potassium-bearing rock effectively through solid-state fermentation. Molecular phylogeny and 16S rRNA gene sequence analysis demonstrated the bacterial strain was a member of the Streptomyces genus. To assess its potential to release potassium from silicate minerals, this strain was used to degrade potassium-bearing rock powder by solid-state fermentation. After fermentation, the amount of water-soluble Al, Fe and K of the substrate with active inoculum was higher than those of the control, which had autoclaved inoculum, and those of the fresh substrate. The result indicated that the strain had the ability to weather potassium-bearing rock and could be used as an inoculum in the production of potassium bio-fertilizer, due to its potassium release activity from rock and tolerance to high temperature.     

南海西沙海槽沉积物细菌多样性初步研究

对来自南海西沙海槽的深海沉积物进行总DNA提取,并构建细菌16S rDNA文库。细菌16S rDNA系统发育分析表明沉积物中细菌分属4个类群：变形杆菌(Proteobacteria)、浮霉菌(Planctomycene)、低G+C含量革兰氏阳性菌和放线菌(Actinobacteria),它们分别占总体的49%、22%、22%和7%。Proteobacteria类群又以δ Proteobacteria亚群占优势,其他分属α 和γ Proteobacteria亚群。Planctomycene和低G+C含量革兰氏阳性菌两个常见于浅海的类群,在西沙海槽沉积物的丰度高于其他深海沉积物,可能是随沉积物被浊流搬运至海槽。     

Isolation and identification of cadmium- and lead-resistant lactic acid bacteria for application as metal removing probiotic

The purpose of the present study was to isolate and identify the metal-resistant lactic acid bacteria from sediments of coastal aquaculture habitats for removal of cadmium and lead from ambience. Collected sediment samples were used to isolate the cadmium- and lead-resistant bacterial colonies by spread plate technique using agar media (De Man, Rogosa and Sharpe) supplemented with cadmium or lead at 50?mg/l. Isolates were identified by bacterial colony polymerase chain reaction and sequencing of 16S ribosomal deoxyribonucleic acid. Metal removing probiotic was determined by characterizing the lactic acid yield in culture media, viability in fish intestine, metal-resistant and metal-removal efficiencies. 16S ribosomal deoxyribonucleic acid sequencing data of five (Cd10, Cd11, Pb9, Pb12 and Pb18) and other all isolates clearly showed 99?% similarities to Enterococcus faecium and Bacillus cereus, respectively. The Pb12 exhibited higher lactic acid yield (180?mmol) than that of the remaining E. faecium strains and excellent viability without pathogenicity; therefore, further study was carried out using Pb12 strain. The selected Pb12 strain showed elevated metal resistant (minimum inhibitory concentrations 120 and 800?mg/l for cadmium and lead, respectively) and removal efficiencies [Cadmium 0.0377?mg/h/g and lead 0.0460?mg/h/g of cells (wet weight)]. From the viability and metal removal points of view, it can be concluded that isolated metal-resistant E. faecium Pb12 strains might be used as potential probiotic strains for removing heavy metals from fish intestinal milieu to control the progressive bioaccumulation of heavy metals in the fish.     

Isolation and characterization of a novel native Bacillus strain capable of degrading diesel fuel

The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was investigated in this research. Ten bacterial strains were isolated from the oil refinery field in Tehran, Iran. Two biodegradation experiments were performed in low and high (500 and 10000 ppm, respectively) concentration of diesel fuel for 15 days. Only two isolates were able to efficiently degrade the petroleum hydrocarbons in the first test and degraded 86.67% and, 80.60 % of diesel fuel, respectively. The secondary experiment was performed to investigate the toxicity effect of diesel fuel at high concentration (10000 ppm). Only one strain was capable to degrade 85.20 % of diesel fuel at the same time (15 days). Phenotype and phylogeny analysis of this strain was characterized and identified as diesel-degrading bacteria, based on gram staining, biochemical tests, 16S rRNA gene sequence analysis. These results indicate that this new strain was Bacillus sp. and could be considered as Bacillus Cereus with 98 % 16 S rRNA gene sequence similarity. The results indicate that native strains have great potential for in situ remediation of diesel-contaminated soils in oil refinery sites.     

Isolation and molecular characterization of some copper biosorped strains

The biosorption of copper (II) from aqueous solution using different bacterial strains was studied. Copper-biosorbing bacteria were isolated from tannery effluent collected from Borg Al-Arab, Alexandria, Egypt. These isolates displayed different degrees of copper biosorption under aerobic conditions. Based on 16S rDNA gene sequence analysis, three of them (S2, S5 and S7) were identified as Chryseobacterium sp., Enterobacter sp. and Stenotrophomonas sp., respectively. Initial copper (II) ion concentrations from 25–250 mg/L at constant temperature 30 °C were studied. The residual copper (II) concentration and its toxicity effect in solution were determined using atomic absorption spectrophotometer and bioluminescent bioreporter. The bioluminescence inhibition of strain (S5) reached to 91.4 % as compared with the strain (S7) reached to 83.3 % at 225 mg/L of copper ion where the maximum biosorption efficiency for S5 and S7 were 71 % and 70.1 % correspondingly using atomic absorption. The bioluminescent bioreporter was proved to be fast and accurate technique for measurement the toxicity effect of residual copper (II) in solution.     

Isolation,biodegradation ability and molecular detection of hydrocarbon degrading bacteria in petroleum samples from a Brazilian offshore basin

The detection of microorganisms with potential for biodeterioration and biodegradation in petroleum fields is of great relevance, since these organisms may be related to a decrease in petroleum quality in the reservoirs or damage in the production facilities. In this sense, petroleum formation water and oil samples were collected from the Campos Basin, Brazil, with the aim of isolating microorganisms and evaluating their ability to degrade distinct classes of hydrocarbon biomarkers (9,10-dihydrophenanthrene, phytane, nonadecanoic acid and 5α-cholestane). Twenty eight bacterial isolates were recovered and identified by sequencing their 16S rRNA genes. Biodegradation assays revealed that bacterial metabolism of hydrocarbons occurred through reactions based on oxidation, carbon–carbon bond cleavage and generation of new bonds or by the physical incorporation of hydrocarbons into microbial cell walls. Based on the biodegradation results, selective PCR-based systems were developed for direct detection in petroleum samples of bacterial groups of interest, namely Bacillus spp., Micrococcus spp., Achromobacter xylosoxidans, Dietzia spp. and Bacillus pumilus. Primer sets targeting 16S rRNA genes were designed and their specificity was confirmed in silico (i.e. computational analysis) and in PCR reactions using DNA from reference strains as positive and negative controls. Total DNA from oil was purified and the amplification tests revealed the presence of the target bacteria in the samples, unraveling a significant potential for petroleum deterioration in the reservoirs sampled, once proper conditions are present for hydrocarbon degradation. The application of molecular methods for rapid detection of specific microorganisms in environmental samples would be valuable as a supporting tool for the evaluation of oil quality in production reservoirs.     

http://www.sciencedirect.com/science/article/pii/S1674987111001290

The Three Gorges Dam(TGD) of the Yangtze River.China,is one of the largest irrigation and hydroelectric engineering projects in the world.The effects of huge man-made projects like TGD on fauna and macrophyte are obvious,mainly through changes of water dynamics and flow pattern;however, it is less clear how microorganisms respond to such changes.This research was aimed to examine differences in microbial diversity at different seasons and locations(in front of and behind the TGD).In addition, differences between particle-attached and free-living communities were also examined.The community structures of total and potentially active microorganisms in the water columns behind and in front of the TGD were analyzed with the DNA- and RNA-based 16S rRNA gene phylogenetic approaches over three different seasons.Clone libraries of 16S rRNA genes were prepared after amplification from extracted DNA and.for some samples,after preparing cDNA from extracted rRNA.Differences were observed between sites at different seasons and between free-living and particle-attached communities.Both bacterial and archaeal communities were more diverse in summer than in winter, due to higher nutrient levels and warmer temperature in summer than in winter.Particle-attached microorganisms were more diverse than free-living communities,possibly because of higher nutrient levels and heterogeneous geochemical micro-environments in particles.Spatial variations in bacterial community structure were observed,i.e..the water reservoir behind the TGD(upstream) hosted more diverse bacterial populations than in front of the dam(downstream),because of diverse sources of sediments and waters from upstream to the reservoir.These results have important implications for our understanding of responses of microbial communities to environmental changes in river ecosystems affected by dam construction.     

一株产铁载体细菌的筛选及其与云母的相互作用

        产铁载体细菌与云母类矿物相互作用的研究有助于了解矿物生物风化和土壤形成的演化规律和机理。采用纯培养法 自南京龙山废钾矿区酸模根际土壤分离筛选到一株高产荧光铁载体的细菌Z6,通过16S rDNA 序列分析和生理生化反应将其 鉴定为假单胞菌属（Pseudomonas sp.）;通过室温静置培养试验研究Z6 菌株与云母的相互作用结果表明,细菌生长代谢前期 （8~15 d）快速产生大量铁载体,菌株与矿物共培养75 d 后,产铁载体细菌对云母类矿物确实产生了风化作用,黑云母组发 酵液中Fe 含量增加了211 倍,Si 含量增加了约27.8 倍,SEM 显示云母表面出现溶蚀坑,细菌可以在矿物表面形成生物膜或 矿物- 细菌复合物。不同矿物对共培养体系中细菌数量、荧光铁载体含量、溶液pH 的影响不同。