南极菲尔德斯半岛表层土壤样品中细菌多样性的系统发育分析

通过PCR结合变性梯度凝胶电泳(DGGE)技术对从南极长城站附近表层土壤样品中获得16SrDNA序列特征片段V3区序列进行分离。对其中的主要12条DGGE条带进行胶回收,获得的DNA片段经测序以及计算机比对分析发现,它们分别属于β、γ、δ-变形细菌(Proteobac-teria)、噬纤维菌-屈挠杆菌-拟杆菌(Cytophaga-Flexibacter-Bacteroides,CFB)群细菌、放线细菌(Actinobacteria)、蓝细菌属(Cyanobacteria)、酸杆菌属(Acidobacteria)和绿屈挠菌属(Chlo-roflexi)等系统分类群。南极表层土壤样品中的大部分16S rDNA序列与从其他土壤或沉积物样品中直接获得的序列相似性较高(93%-100%)。     

一株产海藻糖合成酶南极海洋低温细菌的鉴定

从南极普里兹湾海域海水中分离到一株产海藻糖合成酶的海洋低温细菌BSw10041,革兰氏阴性,杆状,有极生鞭毛,能运动,菌落半透明。进行了常规生理生化和BIOLOG GN2细菌鉴定系统测试,结果表明菌株BSw10041与恶臭假单胞菌(Pseudomonas putida)的表型特征非常相似。为了进一步确定菌株BSw10041的分类学地位,测定了其16S rDNA序列,分析了相关细菌相应序列的同源性,构建了系统发育树,结果表明BSw10041与P．putida的亲缘关系最近。综合上述结果,菌株BSw10041可鉴定为Pseudomonas putida,定名为Pseudomonas putida BSw10041。     

一株可利用二甲基巯基丙酸内盐生长的北极海洋细菌的分类鉴定及表型特征分析

二甲基巯基丙酸内盐(DMSP)是一种主要由海洋浮游植物生成的含硫化合物,在海洋中含量丰富,同时也是海洋细菌的重要营养物之一.采用生长选择性培养基从北南王湾海水中分离到一株细菌DMSP-1.基于16S rRNA基因序列及基因组平均核苷酸一致性(Average Nucleotide Identity,ANI)分析,将该菌鉴...     

一株湿地水体脱氮好氧反硝化细菌的分离鉴定及其特性

为了明确好氧反硝化微生物在氮元素污染湿地水体原位修复工程中的可行性,采用培养基富集,NO3-BTB平板划线法,从大庆湿地筛选到一株好氧反硝化细菌DQ1,通过生理生化测定和16S rRNA测定(登录号为:JQ669957)鉴定为恶臭假单胞菌(Pseudomonas putida)。菌株DQ1在以硝酸盐为唯一氮源,以柠檬酸为唯一碳源,在30℃的条件下静止培养30 h,总氮(TN)去除率达到91.9%,整个过程中没有检测到亚硝态氮(NO2-—N)的积累;在初始氮源浓度为1 930 mg/L,以柠檬酸、酒石酸钾钠、无水乙酸、葡萄糖和乙醇等为唯一碳源,5d总氮去除率分别为97.4%、97.1%、97.2%、97.6%和98.5%。当pH为6.5、6.95、7.45、8.0和8.5时,5 d总氮去除率分别为93.71%、97.27%、97.59%、97.35%和96.85%;当初始pH为7.45时,总氮去除率最高达97.59%,菌株DQ1在温度20~37℃范围内,5 d总氮去除率分别为98.03%、98.12%、98.23%和98.05%。     

低温β-半乳糖苷酶产生菌的筛选、鉴定、生长特性及酶学性质的初步研究

自北冰洋楚科奇海、加拿大海盆、格陵兰海和中国南极中山站近岸的海水、海冰和沉积物样品中分离的322株低温细菌中筛选出73株低温β-半乳糖苷酶产生菌,并对其中1株BCw006进行了研究。通过16S rDNA序列同源性分析表明,该菌株属于交替单胞菌属,定名为Alteromonas sp.BCw006。对该菌株研究表明:该菌最适生长和产酶温度为24℃;在pH6.0—8.0、含0%—6.O% NaCl的培养基条件下菌株能够较好地生长与产酶,其最适生长和产酶NaCl浓度分别为3%和1%,乳糖对β-半乳糖苷酶合成具有明显诱导作用,酵母粉和蛋白胨是菌株生长和产酶较适宜的氮源,酶的最适作用温度为35℃,0℃时能保持35℃下酶活的25%左右,表明其具有较好的适应低温特性。酶对热敏感,60℃时作用30min后酶活力下降了41%。     

砾间接触氧化反应器中细菌多样性评价

采用分子生物学手段,通过构建16S rDNA基因文库,对新型剩余污泥减量化处理系统——砾间接触氧化反应器中细菌多样性进行了系统发育分析;通过多样性指数、丰富度指数、均匀度指数及优势度指数,对细菌多样性及优势菌种富集状况进行了系统评价。结果表明:共有80个克隆子,分别代表29个OTU,用于系统细菌分析。其中,石球外膜46个克隆子(17个OTU),石球内泥34个克隆子(12个OTU)。生物膜中细菌多样性及优势菌种富集状况均好于孔隙内泥中的细菌。     

吉尔吉斯斯坦伊塞克湖一处土壤样品细菌多样性

采用纯培养方法从吉尔吉斯斯坦共和国伊塞克湖一处温泉旁的土壤中分离到32株细菌,通过ARDRA 分析后得到不同的类群,从各个类群中随机选取1个代表菌株进行16S rDNA 序列测定和系统发育的分析。结果表明：分离的菌株分布在假单胞菌属（Pseudomonas）、类芽孢杆菌属（Paenibacillus）、芽孢杆菌属（Bacillus）、寡养单胞菌属（Stenotrophomonas）、Lysinibacillus、溶杆菌属（Lysobacter）、短芽孢杆菌属（Brevibacillus）、根瘤菌属（Rhizobium）、变形杆菌属（Proteus）等9个属,且部分菌株的16S rDNA序列同源性低于97%,可能是潜在的新种。结果揭示了该样点可培养细菌种群的多样性及独特性。     

南极欺骗岛土壤细菌群落结构和多样性分析

采用基于16S r DNA克隆文库的非培养方法和传统培养方法相结合的手段,对南极欺骗岛土壤细菌群落结构及多样性进行了初步分析。对来自16S r DNA克隆文库的118个阳性克隆进行测序和序列比对,结果显示细菌来自放线菌门(Actinobacteria)、变形杆菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)3大门的39个操作分离单元(OTU),其中优势菌群为放线菌门和变形杆菌门,分别占65.25%和28.81%。放线菌门的主要优势属为鱼孢菌属(Sporichthya)、类诺卡式氏菌属(Nocardioides)、束缚菌属(Conexibacter)、Gaiella和节杆菌属(Arthrobacter)。变形杆菌门的主要优势属为鞘氨醇单胞菌属(Sphingomonas)、硫杆菌属(Thiobacillus)、寡养单胞菌属(Stenotrophomonas)和热单胞菌属(Thermomonas)。采用6种培养基对细菌进行培养和分离,共得到57株菌,来自放线菌门、变形杆菌门、拟杆菌门和厚壁菌门4大门的13个OTU,其中优势菌群为放线菌门和变形杆菌门,分别占57.89%和31.58%。优势属是放线菌门的节杆菌属(Arthrobacter)、雷夫松氏菌属(Leifsonia)和变形杆菌门的假单胞菌属(Pseudomonas)。本论文为研究欺骗岛土壤细菌多样性以及有益菌种资源的开发和利用奠定了基础。     

两种泥炭藓种群年龄结构与生长特征的对比分析

2004年8月中旬,在长白山西侧龙岗山脉中部的哈尼泥炭沼泽,应用“固有年际标记”方法,研究了中位泥炭藓(Sphagnum.magellanicum)与疣壁泥炭藓(Sphagnum papillosum)两种群分株数量和生物量的年龄结构、生物量和高度生长规律。结果表明:中位泥炭藓种群共分为4个龄级,分株的数量和生物量的年龄结构均呈稳定型;疣壁泥炭藓种群亦分4个龄级,但分株的年龄结构呈衰退型。两种泥炭藓种群分株每年生长的高度大体上相同,分株高度与龄级间均呈较明显的单调线性关系(p<0.01),两种群虽未出现异速生长现象,但老龄植株的高度、生物量变异程度均小于幼龄株。这与老龄级分株对水、养分及光资源的吸收利用的权衡能力较强有一定关系。     

氢氧化铁共沉淀电感耦合等离子体发射光谱法测卤水中的痕量钴镍锰

用氢氧化铁共沉淀分离卤水中的钴镍锰,用1+1的王水溶解沉淀定容,电感耦合等离子发射光谱法测定。检出限为LD(Co Mn)=0.10 mg/L,LD(Ni)=0.27 mg/L,加标回收率为95.00%～102.0%,精密度(n=12)为1.05%。结果表明,本方法快速准确,可以准确测定卤水中钴镍锰。     

Direct PCR amplification of the 16S rRNA gene from single microbial cells isolated from an Antarctic iceberg using laser microdissection microscopy

Here, we describe a technique that allows the genetic linage analysis of 16S rRNA genes in bacteria observed under a microscope. The technique includes the isolation of microbial cells using a laser microdissection microscope, lysis of the cells, and amplification of the 16S rRNA genes in the isolated cells without interference by bacterial DNA contamination from the experimental environment or reagents. Using this technique, we successfully determined 15 16S rRNA gene sequences in cells isolated from an Antarctic iceberg. These sequences showed 94%–100% identity to their closest strains, which included bacteria that occur in aqueous, marine, and soil environments.     

Stability Behavior and Thermodynamic States of Iron and Manganese in Sandy Soil Aquifer,Manukan Island,Malaysia

A total of 20 soil samples were collected from 10 boreholes constructed in the low lying area, which included ancillary samples taken from the high elevation area. Redox processes were investigated in the soil as well as groundwater in the shallow groundwater aquifer of Manukan Island, Sabah, Malaysia. Groundwater samples (n = 10) from each boreholes were also collected in the low lying area to understand the concentrations and behaviors of Fe and Mn in the dissolved state. This study strives to obtain a general understanding of the stability behaviors on Fe and Mn at the upper unsaturated and the lower-saturated soil horizons in the low lying area of Manukan Island as these elements usually play a major role in the redox chemistry of the shallow groundwater. Thermodynamic calculations using PHREEQC showed that the groundwater samples in the study area are oversaturated with respect to goethite, hematite, Fe(OH)₃ and undersaturated with respect to manganite and pyrochroite. Low concentrations of Fe and Mn in the groundwater might be probably due to the lack of minerals of iron and manganese oxides, which exist in the sandy aquifer. In fact, high organic matters that present in the unsaturated horizon are believed to be responsible for the high Mn content in the soil. It was observed that the soil samples collected from high elevation area (BK) comprises considerable amount of Fe in both unsaturated (6675.87 mg/kg) and saturated horizons (31440.49 mg/kg) compared to the low Fe content in the low lying area. Based on the stability diagram, the groundwater composition lies within the stability field for Mn²⁺ and Fe²⁺ under suboxic condition and very close to the FeS/Fe²⁺ stability boundary. This study also shows that both pH and Eh values comprise a strong negative value thus suggesting that the redox potential is inversely dependent on the changes of pH.     

湿地土壤铁的分析测定方法比较

结合湿地土壤滞水缺氧特征,根据不同研究需要比较了现有常用的铁元素分析测定方法。通过比较发现,可用于湿地土壤铁分析测定的方法有10余种,其中全量测定以原子吸收光谱法或电感耦合等离子体发射光谱法在准确度、灵敏度和检出时间上优于各类比色法;BPDS-EDTA双络合紫外一可见分光光度法是能稳定铁价态并准确同时测定2种价态铁含量的最有效方法;鉴于湿地土壤明显的空间异质性,基于重金属分级研究而改进的连续浸提法优于经典的铁氧化物种类的独立区分;考虑到铁价态与种类的精确刻度对湿地环境变化研究的重要指征价值,价态区分与种类区分采用鲜土即时测定比风干土更能反映土壤的自然实貌。     

Geographic Dimensions of Relocation Activity: A Comparative Analysis of Intrametropolitan and Out-of-State Relocation Activity

Over the years, research on relocation activity has provided insights about the characteristics of firms and regions that drive relocation. The spatial dimensions of these relocation decisions, however, particularly within states or metropolitan areas, remain an understudied aspect of the relocation literature. There is also little work comparing the destinations of relocations originating from within metropolitan areas compared to relocation activity from other states. Given the theoretical and practical importance of higher resolution, comparative research on relocation activity within metropolitan areas, this article uses both areal and point-based spatial statistics to test hypotheses about similarities and differences in the relocation behavior of locally oriented and out-of-state businesses within the Phoenix, Arizona, metropolitan area. Analytical results highlight distinct differences in the destinations of relocation activity originating from within the metropolitan area compared to out-of-state relocation activity. Intrametropolitan relocations tend to locate in less expensive and racially and ethnically diverse neighborhoods, whereas out-of-state relocations locate in wealthier, well-known locations of the metropolitan area. Out-of-state relocations are also less likely to locate in the downtown core. This suggests that expensive smokestack-chasing efforts directed at attracting businesses from out of state are unlikely to help revitalize the downtown core.     

An Analysis of the Published Mineral Resource Estimates of the Haji-Gak Iron Deposit,Afghanistan

The Haji-Gak iron deposit of eastern Bamyan Province, eastern Afghanistan, was studied extensively and resource calculations were made in the 1960s by Afghan and Russian geologists. Recalculation of the resource estimates verifies the original estimates for categories A (in-place resources known in detail), B (in-place resources known in moderate detail), and C₁ (in-place resources estimated on sparse data), totaling 110.8 Mt, or about 6% of the resources as being supportable for the methods used in the 1960s. C₂ (based on a loose exploration grid with little data) resources are based on one ore grade from one drill hole, and P₂ (prognosis) resources are based on field observations, field measurements, and an ore grade derived from averaging grades from three better sampled ore bodies. C₂ and P₂ resources are 1,659.1 Mt or about 94% of the total resources in the deposit. The vast P₂ resources have not been drilled or sampled to confirm their extent or quality. The purpose of this article is to independently evaluate the resources of the Haji-Gak iron deposit by using the available geologic and mineral resource information including geologic maps and cross sections, sampling data, and the analog-estimating techniques of the 1960s to determine the size and tenor of the deposit.