天山根瘤菌(R.tianshanense)模式菌株16SrDNA全序列测定及其系统发育

对天山根瘤菌群的模式株A－IBS（＝CCBAU3306）16SrDNA的全序列进行了测定，以确定它在系统发育中的地位。实验中设计了6个引物，通过聚合酶链反应扩增天山根瘤菌模式菌株A－IBS的16SrDNA。应用DNA定向测序技术，获得了菌株A－IBS的16SrDNA全序列，将所得序列与根瘤菌已知种的模式菌株16SrDNA全序列一起进行聚类分析，得到了系统发育树状图。在树状图中，菌株A－IBS所代表的根瘤菌群与华癸根瘤菌（R．huakuu）群、鹰嘴豆根瘤菌（R.ciceri）群、地中海根瘤菌（R．mediterrranean）群及百脉根根瘤菌（R．loti）群的亲缘关系较近，与其它根瘤菌群的亲缘关系较远，存在着属水平的差异，表明了这些相近根瘤菌群构成了根瘤菌的一个独立的发育系。     

天山根瘤菌模式菌株全序列测定及其系统发育

对天山根瘤菌群的模式株Ａ－ＩＢＳ１６ＳｒＤＮＡ的全序列进行了测定，以确定它在系统发育中的地位。实验中设计了６个引物，通过聚合酶链反应扩增天山根瘤菌模式菌株Ａ－ＩＢＳ的１６ＳｒＤＮＡ。应用ＤＮＡ定向测序技术，获得了菌株Ａ－ＩＢＳ的１６ＳｒＤＮＡ全序列，将所得序列与根瘤菌已知种的模式菌株１６ＳｒＤＮＡ全序列一起进行聚类分析，得到了系统发育树状图，在树状图中，菌株Ａ－ＩＢＳ所代表的根瘤菌群与华癸根瘤菌群     

快生型大豆根瘤菌（Rhizobium fredii）3．7Kb增效片段的亚克

利用柯氏质粒ｐＬＡＦＲ１为载体构建了快生型大豆根瘤菌Ｂ５２菌株的基因文库，并通过植物结瘤试验筛选到一个３．７Ｋｂ增效片段，将其导入慢生型大豆根瘤菌２２１０，能提高其共生固氮效率。所得高效菌株ＨＮ３２在黑龙江、四川和广西大面积应用，平均增产１１．４％（５）。本文测定了３．７Ｋｂ片段的核苷酸序列，计算机分析发现含有两个开放阅读框架（ＯＲＦｓ）。ＯＲＦ１编码含１９０个氨基酸的多肽，与已报道基因和多肽的同源性很低，但其Ｎ端１９个氨基酸与发根农杆菌的乳糖转移酶高度同源。ＯＲＦ２编码含２３５个氨基酸的多肽，与碗豆根瘤菌的ｈｕｐＥ及苜蓿根瘤菌的糖基转移酶基因显示５４％的同源性。     

醋酸钙不动杆菌PHEA-2的16S rDNA测序及其苯酚降解特性研究

从我国东北某炼油厂工业废水中分离到一株高效降解苯酚的菌株ＰＨＥＡ－２,采用ＰＣＲ技术从该菌总ＤＮＡ中克隆到１５００ｂｐ的１６Ｓ ｒＤＮＡ片段。该片段的核苷酸序列分析结果表明,ＰＨＥＡ－２的１６Ｓ ｒＤＮＡ核苷酸序列与醋酸钙不动杆菌模式菌株的同源性为９８％。在细菌系统发育分类学上,ＰＨＥＡ－２归属变形细菌γ亚类中的不动杆菌属,醋酸钙不动杆菌,ＰＨＥＡ－２除了能够降解苯酚外,还能降解苯甲酸盐和邻苯二酚     

应用PCR-DGGE技术分析长江口低氧区的细菌群落组成

应用PCR结合变性梯度凝胶电泳（PCR-DGGE）技术对长江口外低氧区的细菌群落组成和优势菌群进行了分析。对25条DGGE条带进行了克隆、测序,所得到的细菌16SrDNA基因V3区序列进行了系统进化分析。结果显示这25条条带分别归属于4个细菌类群：变形菌门（Proteobacteria）、拟杆菌门（Bacteroides）、厚壁菌门（Finnicutes）和蓝细菌门（Cyanobacteria）。其中有16条分别与变形细菌亚群的γ-Proteobacteria和δ-Proteobacteria相似。时空分析发现,低氧水体的细菌群落组成与非低氧水体的组成不同,低氧水体包括变形菌门（Proteobacteria）、拟杆菌门（Bacteroides）、厚壁菌门（Finnicutes）和蓝细菌门（Cyanobacteria）,非低氧水体中没有发现蓝细菌门（Cyanobacteria）。并且8月份低氧水体中Flavobacteria为优势菌群。     

大菱鲆红体病虹彩病毒ATPase基因的克隆与序列分析

克隆了大菱鲆红体病虹彩病毒(TRBIV)的重要功能蛋白——腺苷三磷酸酶(adenosine triphosphatease,ATPase)基因的全部编码区及其上下游部分的核苷酸序列。经多序列比对和分析发现,TRBIV与GenBank中6种代表性虹彩病毒的同源性介于35％～98％之间。绘制出的包含TRBIV在内的14种虹彩病毒的系统发育树证实,TRBIV是一种新的鱼类虹彩病毒,其分类地位处在虹彩病毒科待指定病毒属内的真鲷虹彩病毒亚群和传染性脾肾坏死病毒亚群之间。     

北极太平洋扇区深海沉积物的细菌多样性研究

对北极太平洋扇区4个站位深海表层沉积物样品,采用PCR结合变性梯度凝胶电泳(PCR-DGGE)技术进行了细菌16S rRNA基因V3区序列的系统发育分析.结果表明,沉积物中的细菌多样性丰富,获得的40条序列归属于4个细菌类群:变形细菌(Proteobacteria,占全部序列的75%)、噬纤维菌-屈挠杆菌-拟杆菌群(Cytophaga-Flexibacter-Bacteroides,CFB,占10%)、放线细菌(Actinobacteria,占10%)和酸杆菌(Acidobacteria,占5%).其中变形细菌(包括α、β、γ和δ-Proteobacteria),而γ-Proteobacteria占全部序列的62.5%,是很明显的优势类群.在这些细菌类群中,β、γ-Proteobacteria在4个站位沉积物中均有分布.     

海水附着细菌多样性和群落演替的研究

通过细菌16S rRNA基因(16S rDNA)文库方法研究了1至7天近海浸海玻片附着细菌的多样性和群落演替特征.从1至7天3个基因文库中共筛选了269个克隆、144个有效分类操作单元 (OUT)并对其全部测序.16S rDNA序列系统进化分析发现,这些细菌主要归属于8个细菌门类:变形菌门(Proteobacteria)(α-、γ-和δ-亚群)、拟杆菌门(Bacteroidetes)、芽单胞菌门(Gemmatimonadetes)、厚壁菌门(Firmicutes)、浮霉菌门(Planctomycetes) 、光合细菌门(Cyanobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacter ia).由此可知1周内变形菌门的α-亚群、γ-亚群和拟杆菌门的细菌是常见的附着类群;α-变形菌亚群中的玫瑰杆菌族(Roseobacter clade)是海洋环境中比较常见的早期附着种类;由聚类分析显示3天和7天细菌的群落结构相似.这些实验结果为了解海水附着细菌生物膜形成的演替过程提供了理论基础,并为海水微生物腐蚀控制提供了生物学线索.     

快生型大豆根瘤菌3.7Kb增效片段的亚克隆与序列分析

利用柯氏质粒ｐＬＡＦＲ１为载体构建了快生型大豆根瘤菌Ｂ５２菌株的基因文库，并通过植物结瘤试验筛选到一个３．７Ｋｂ增效片段，将其导入慢性型大豆根瘤菌２２１０，能提高其共后固氮效率。     

基于高通量法分析鲐鱼冻藏期间的微生物群落变化

目的 分析不同冻藏时期鲐鱼表面微生物群落的变化,为鲐鱼冻藏期间微生物安全控制提供相关依据。方法 将新鲜鲐鱼冻藏于-18 ℃冰箱中,分别在冻藏前、冻藏40 d与冻藏100 d时取样,采用高通量测序技术提取分析其表面微生物。结果 冻藏鲐鱼样品操作分类单元（Operational taxonomic units,OTU）数量范围为115~266,优化有效序列为38 899~45 012条;其中,样品在冻藏前的OTU数量最高,冻藏100 d时的OTU数量最低,此时样品的Ace,Chao,Shannon等3个指数均值偏低,但Simpson指数较高,可见其菌群种类和丰度较低;同时,嗜冷杆菌（Psychrobacter）和鞘氨醇单胞菌（Sphingomnnas）为样品冻藏前的优势菌群,而在冻藏40 d时不动杆菌（Acinetobacter）也成为样品的主要微生物;当样品在冻藏100 d时,其优势菌群为乳球菌（Lactococcus）和芽孢杆菌（Bacillus）等。结论 鲐鱼样品在不同冻藏时期的菌群组成存在较大差异,表明冻藏时间对菌群组成有明显影响。     

Characterization of phenol degradation by Rhizobium sp. CCNWTB 701 isolated from Astragalus chrysopteru in mining tailing region

To screen high strength phenol degrading bacteria, we selected 108 rhizobial strains isolated from nodules of eight wild legumes species in the mining tailing region of Shaanxi province, northwest of China, and cultivated them in a basal salt (BS) medium supplemented with different phenol concentrations as a sole carbon source. The results showed that some of the strains could use phenol as sole carbon source. In order to study the characteristics of phenol degradation, the strain CCNWTB701 isolated from Astragalus chrysopteru was used as well, due to the fact that it was very efficient in phenol degradation. The phenol degradation was around 99.5 and 78.3%, with an initial concentration of 900 and 1000 mg/l phenol in 62 and 66 h, respectively. Kinetic studies indicated that the strain had a high KS (743.1 microM) and an extremely high KSI (10,469 microM) in Haldane's model. The phylogenetic analysis based on 16S rRNA gene sequences showed that CCNWTB701 belonged to the Rhizobium genus, and it was closely related to Rhizobium mongolense and Rhizobium gallicum.     

三个根瘤菌新亚群的16S rDNA-RFLP分析

在对新疆，内蒙干旱地区采集的４８株苜蓿，草木樨，锦鸡儿根瘤菌进行数值分类和ＳＤＳ－ＰＡＧＥ全细胞蛋白分析的基础上。     

Isolation and characterization of phenanthrene-degrading strains Sphingomonas sp. ZP1 and Tistrella sp. ZP5

Two bacteria strains Sphingomonas sp. strain ZP1 and Tistrella sp. strain ZP5 were identified as phenanthrene-degrading ones, based on Gram staining, oxydase reaction, biochemical tests, FAME analysis, G+C content and 16S rDNA gene sequence analysis. We isolated these two bacteria strains Sphingomonas sp. ZP1 and Tistrella sp. ZP5 from soil samples contaminated with polycyclic aromatic hydrocarbon (PAH)-containing waste from oil refinery field in Shanghai, China. Strain Sphingomonas sp. ZP1 was able to degrade naphthalene, phenanthrene, toluene, methanol and ethanol, salicylic acid and Tween 80. Moreover, it can remove nearly all the phenanthrene at 0.025% concentration in 8 days. Strain Tistrella sp. ZP5 cannot degrade phenanthrene individually but it can increase the speed of phenanthrene degradation together with ZP1. The growth conditions of strain Sphingomonas sp. ZP1 were optimized. The result also indicated that the degradation rate of phenanthrene ranged from 250 to 1000 ppm with strain ZP1 remained nearly the same, i.e., a high concentration of phenanthrene did not inhibit both the growth of microbial strains and the phenanthrene-degradation ability. Besides, the effect of non-ionic surfactants such as Brij 30, Triton X-100 and Tween 80 on the phenanthrene degradation was determined. Such two strains may be useful for bioremediation applications.     

氯代芳香族污染物生物降解菌株的分离及其降解质粒的初步研究

从工业废水污染的水体和污泥中,分离并筛选到６株对氯苯和苯酚类有机污染物高浓度耐受力的细菌菌株。６株降解细菌能在氯代苯和氯代酚作为唯一碳源的培养介质中生长,具有不同程度降解这类有机污染物的代谢能力,除２号和５号菌外,所筛选的其它４株降解细菌均含有一个或多个质粒。采用２,４－Ｄ单加氧酶基因ｔｆｄＡ的保守引物和ＰＣＲ扩增技术,证明在２号和６力的染色体和３号菌的大质粒上含有ｔｆｄＡ基因的同源序列。     

Orientation, stress, and strain in an (001) barium titanate single crystal with 90° lamellar domains determined using electron backscatter diffraction

The orientation, stress, and strain in a single crystal of barium titanate (BaTiO₃), containing relatively large (0.5–14.5 μm), parallel, lamellar domains, have been determined and mapped using electron backscatter diffraction (EBSD). The strain distribution in the single crystal was determined using cross-correlation analysis of the EBSD patterns. Strain in the (001) single crystal was dominated by strain in the minority a-domain bands with peak values of ?0.006 determined in the surface plane, perpendicular to the intersection of the domain walls with the crystal surface, compared to +0.002 in the same direction for the majority c-domains. The out-of-plane strains were negatively correlated with the in-plane strains and were about a factor of two smaller. The experimentally determined strains peak at domain boundaries and suggest a contraction of the c-axis and an expansion of one of the a-axes as the domain wall is approached. The ratios of the in-plane and out-of-plane strains were consistent with the bulk elastic constants of BaTiO₃. Stress values determined from the strains and the elastic constants peaked at 400 MPa.     

Isolation of the epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene resin

epsilon-Caprolactam has high COD and toxicity, so its discharge to natural water and soil systems may lead to an adverse environmental effect on water quality, endangering public health and welfare. This investigation attempts to isolate epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene (ABS) resin. The goal is to elucidate the effectiveness of isolated pure strain and ABS mixed strains in treating varepsilon-caprolactam from synthetic wastewater. The results reveal that Paracoccus versutus MDC-3 was isolated from the wastewater treatment system manufactured with ABS resin. The ABS mixed strains and P. versutus MDC-3 can consume up to 1539mg/l epsilon-caprolactam to denitrify from synthetic wastewater. Complete epsilon-caprolactam removal depended on the supply of sufficient electron acceptors (nitrate). Strain P. versutus MDC-3, Hyphomicrobium sp. HM, Methylosinus pucelana and Magnetospirillum sp. CC-26 are related closely, according to the phylogenetic analyses of 16S rDNA sequences.     

Extended time tests on GRP pipe bends

Strain measurements were taken on two glass reinforced plastic (GRP) pipe bend specimens made by hand lay-up from polyester resin and E glass in the form of chopped strand mat. Each specimen consisted of a right angled pipe bend with straight lengths at either end. One end was clamped and the free end loaded to give in-plane flexure of the bend. One specimen was subjected to constant load conditions and the other to constant free end displacement over periods up to 329 hours, during which strains were monitored. Finally both specimens were subjected to continuously increasing load up to fracture. During the constant load test there was a little redistribution of strain, but for the constant displacement test there was considerable relaxation of outside surface strains but little change in the corresponding inside surface strains. Results are compared with those for GRP strip tests under three point bending.     

Steady state strains in power transmitting flat belts made of composite material

Strain data for a simple two pulley belt drive was obtained using a photoelastic coating technique. The operating strains present were not constant along the driving and load sides but varied in an irregular manner. The average strain gradually increased on the driving side and decreased on the load side as the power transmitted was increased.     

Studies on biosorption equilibrium and kinetics of Cd2+ by Streptomyces sp. K33 and HL-12

The sorption of Cd(2+) by Streptomyces sp. K33 and HL-12 was investigated. The removal efficiency increased with pH, but no obvious differences with different temperatures. Fourier transform infrared (FT-IR) was used to characterize the interaction between Cd(2+) and K33 and HL-12. Results revealed that the presence of amino, carboxyl, hydroxyl and carbonyl groups were responsible for the biosorption of Cd(2+). Strain HL-12 had more changes in the functional groups than K33. Biosorption equilibrium was established earlier by strain K33 than that by HL-12, and K33 had higher adsorption ratio. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were used to describe the adsorption experiment, Langmuir model fitted the experiment data best. Strain K33 showed greater sorption capacities with 38.49 mg Cd(2+)/g dry cells. Pseudo-first-order and second-order kinetic models were used to describe the kinetic data, and second-order kinetic model fitted better. About 70% recovery of Cd(2+) could be obtained at pH 相似文献