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Vertical distribution of phosphorus and P-dissolving/ decomposing bacteria in the sediment of Guanting reservoir

Science china Earth sciences 2005年第Z2期48卷 285-294页

作者： LI Cui, YUAN Hongli & HUANG Huaizeng College of Biological sciences, Key laboratory of Agro-microbial Resource and Application, Ministry of Agriculture, china Agricultural University, beijing 100094, china National Research Center of Geoanalysis, beijing 100037, china College of Biological sciences Key Laboratory of Agro-Microbial Resource and Application Ministry of Agriculture China Agricultural University Beijing 100094 China National Research Center of Geoanalysis Beijing 100037 China

In this study, we determined pH, phosphorus content and the number of P-dis- solving/decomposing bacteria in relation to the depth in the sediment of Guanting reservoir in beijing. The pH value was slightly increased from 8.0 in the surface to 8.5 in the bottle (69 cm in depth) of sediment. The highest P content, 1269 mg/kg, was detected in the 35 cm layer, followed by the 5 cm (993 mg/kg) and 69 cm (580 mg/kg) layers. The number of inorganic P-dissolving bacteria varied from 6(102 to 8(104 and the organic P-discomposing bacteria were from 1.9(103 to 6.3(104 per gram sediment in different depths, which were counted under 28℃ and 20℃ ( pH7.5 and 8.5. The number of P-dissolving/discomposing bacteria was directly correlated to the P content in each layer of sediments. The analysis of P-dissolving/decomposing ability of bacteria showed that some of these bacteria were also capable of accumulating P intracellularly. The intracellular P-accumulation was more efficient at lower temperature; in contrast, the activity of P-dissolving/decomposing was stronger at higher temperature. So the content of dissolved P in water body, or quality of water, could be affected by the change of temperature via the regulation of bacterial activity. On the basis of 16S rDNA sequencing, the 13 efficient P-dis- solving/decomposing bacteria were identified as Bacillus spp., Bacterium sp., Microbacterium sp., Paenibacillus sp. and Pseudomonas sp.

关键词： Guanting reservoir, sediment, P-dissolving/decomposing bacteria, phosphorus cycling, eutrophication.

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Effects of man-made algal crusts on water uptake and content of topsoil in Dalateqi County of Inner Mongolia(eastern edge of Qubqi Desert)

Effects of man-made algal crusts on water uptake and content...

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庆祝中国藻类学会成立30周年暨第十五次学术讨论会

作者： Shubin Lan~(a,b),Chunxiang Hu~(a*),Benqiang Rao~(a,b),Li Wu~(a,b),Delu Zhang~(a,b) and Yongding Liu~a a State Key laboratory of Freshwater Ecology and Biotechnology,institute of Hydrobiology, chinese academy of sciences,Wuhan,430072,china b Graduate School of chinese academy of sciences,beijing,100039,china

In order to determine the influence of algal crusts on water uptake(non-rainfall water) and water content of topsoil,Microcoleus vaginatus *** Scytonema javanicum(Kütz) Born et *** from microbial soil crusts of Dalateqi County(Inner Mongolia,the eastern edge of Qubqi Desert) were batch cultured in greenhouse,and spraying inoculated onto the local unstabilized sandy *** a week,the algal crusts formed,and algal biomass obviously changed with the soil water from that time *** the growth of the crusts,they took up and retained more *** water,the part taken up from air had obvious increase since the 15

关键词： biological soil crusts desert algae non-rainfall water upper soil layer

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耐热古菌芝田硫化叶菌海藻糖生成相关酶的基因克隆、表达和序列分析

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生物化学与生物物理进展 2003年第5期30卷 798-802页

作者：吴襟于炜婷王辉刘莉王绍校张树政中国科学院微生物研究所北京100080

从耐热古菌海藻糖芝田硫化叶菌B12中分别克隆出海藻糖生成相关酶———麦芽寡糖基海藻糖合酶的基因treY和麦芽寡糖基海藻糖基水解酶的基因treZ,测定了其核苷酸序列并进行了表达.其中treY编码的蛋白质有 72 8个氨基酸、分子质量为 86ku;t... 详细信息

从耐热古菌海藻糖芝田硫化叶菌B12中分别克隆出海藻糖生成相关酶———麦芽寡糖基海藻糖合酶的基因treY和麦芽寡糖基海藻糖基水解酶的基因treZ,测定了其核苷酸序列并进行了表达.其中treY编码的蛋白质有 72 8个氨基酸、分子质量为 86ku;treZ编码的蛋白质有 5 5 9个氨基酸、分子质量为 6 5ku.它们与已报道的其他微生物的两个海藻糖生成相关酶的基因进行同源性比较,treY和treZ的同源性分别为 93%和 76 % (硫矿硫化叶菌P2)、97%和 95 % (硫矿硫化叶菌KM1)、6 3%和 6 6 % (嗜酸热硫化叶菌ATCC3390 9)、4 8%和 5 0 % (节杆菌Q36 )、4 8%和 5 2 %(根瘤菌M11)、5 0 %和 5 2 %(短杆菌).通过PHYLIP软件进行这些基因序列的分类聚类计算,获得这几种微生物间两个酶类的蛋白质系统进化树;经过氨基酸序列比较分析还发现,所有的海藻糖生成相关酶都含有糖苷酶家族 13中几个高度保守的α 淀粉酶催化活性区。

关键词：耐热古菌芝田硫化叶菌海藻糖酶基因克隆表达序列分析

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食品卫生微生物学检验培养基质量分析

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微生物学通报 2009年第11期36卷 1723-1726页

作者：张颖辉吴清平张菊梅刘秀梅蔡芷荷中国科学院武汉病毒研究所湖北武汉430071 广东省微生物研究所广东省菌种保藏与应用重点实验室广东广州510070 中国科学院研究生院北京100049 中国疾病预防控制中心营养与食品安全所北京100050 广东环凯微生物科技有限公司广东广州510663

为探讨培养基ISO国际标准对国内培养基质控的等效性,选择国内外4家培养基生产厂家的霉菌培养基、酵母菌培养基和显色培养基,从质控菌株生长率、抑菌效果等方面进行质量分析比对试验。生长率质控标准菌株在各种霉菌培养基、酵母菌培养基... 详细信息

为探讨培养基ISO国际标准对国内培养基质控的等效性,选择国内外4家培养基生产厂家的霉菌培养基、酵母菌培养基和显色培养基,从质控菌株生长率、抑菌效果等方面进行质量分析比对试验。生长率质控标准菌株在各种霉菌培养基、酵母菌培养基上的生长率均值均大于0.5,在显色培养基上的生长率均值均大于0.7,符合ISO国际标准。经统计分析,试验的4家培养基厂家生产的培养基质量水平差异不显著(P>0.05),这为将新出台的培养基国家标准拟等效采用培养基ISO国际标准提供了基础材料和依据。

关键词：培养基生长率抑菌效果质量食品卫生

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细菌测试片的冷水可凝凝固剂初步研究和应用

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微生物学通报 2009年第11期36卷 1783-1788页

作者：吴许文吴清平张淑红黄汝添中国科学院武汉病毒研究所湖北武汉430071 广东省微生物研究所广东省菌种保藏与应用重点实验室广东广州510070 中国科学院研究生院北京100049

微生物测试片具有携带方便、不用配制培养基的优点,为一种新型的检测工具。测试片的技术关键是冷水可凝胶,本文通过研究新的冷水可凝凝固剂(HKG)的保水性能、pH、强度、微生物利用及降解和抑菌效果,再组装成细菌菌落总数测试片,进行特... 详细信息

微生物测试片具有携带方便、不用配制培养基的优点,为一种新型的检测工具。测试片的技术关键是冷水可凝胶,本文通过研究新的冷水可凝凝固剂(HKG)的保水性能、pH、强度、微生物利用及降解和抑菌效果,再组装成细菌菌落总数测试片,进行特异性和食品样品效果检验,并与倾注平板法比对,评价其作为微生物测试片凝固剂的可行性。结果显示HKG对16种微生物均无抑菌作用,pH为中性,强度为340.31 g/cm2±48.71 g/cm2;具有良好的保水性能;HKG在短时期(5 d)内不支持微生物生长,不被分解利用,在测试片和倾注培养法中5种测试菌株均可达相同的灵敏度(P=0.438>0.05),各菌株菌落数(P=0.442>0.05)和食品样品菌落数(P=0.718>0.05)比较在统计学上无显著差异。结果表明,HKG能较好地应用于细菌测试片计数,并能提高检测效率。

关键词：快速检测微生物测试片培养基凝固剂

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The secretion of lecithinase of Pseudomonas alcaligenes S2 was via type II secretion pathway

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Science Bulletin 2005年第16期 61-66页

作者： Lü Jing1, LI Fan1, CHEN Sanfeng1,2 & LI Jilun1,3 1. State Key laboratory of Agrobiotechnology, china Agricultural Uni-versity, beijing 100094, china 2. Key laboratory of Agro-microbial Resource and Application in Agri-culture Ministry, china Agricultural University, beijing 100094, china 3. College of Biological sciences, china Agricultural University, beijing 100094, china

Strain S2 is a lecithin (or phosphatidylcholine)- solubilizing bacterium, which was isolated from the rice rhizosphere in rural areas of beijing, china. On the basis of a polyphasic study involving phenotypic tests, physiological and biochemical tests, 16S rDNA sequence analysis, G+C content determination and DNA-DNA hybridizations analy-sis, strain S2 was identified as Pseudomonas alcaligenes. P. alcaligenes S2 was mutagenized with Tn5 and four mutants showing decreased or increased solubilizing ability of lecithin were isolated based on the halo size around colonies on the solid plate supplemented with egg yolk. To characterize the genes of P. alcaligenes S2 involved in solubilization of lecithin, the EcoR I fragments of the chromosomes from the four mutant strains carrying a single transposon were cloned, and the DNA sequences flanking the Tn5 were determined. The Tn5 insertion sites in the mutants M808, M1329 and M1400, showing decreased solubilizing ability of lecithin, were found to be located in the xcpS, xcpX and xcpW , respectively, whose products XcpS, XcpX and XcpW were the components of type II secretion pathway. Complementation of xcpS, xcpX and xcpW could restore the corresponding mutants M808, M1329 and M1400 to solubilize lecithin. The data suggested that mutation in one of these xcp genes would lead to the absence of mature lecithinase secretion into the extracellular medium. The data also indicated that the secretion of leci-thin-hydrolyzing enzyme of P. alcaligenes was via type II secretion pathway. In the mutant M20 showing increasing lecithin-hydrolyzing activity, the interrupted gene showed 86% identity with chpA of Pseudomonas aeruginosa PAO1, whose product plays an important role in controlling twitch-ing motility of the bacterial cells.

关键词： Pseudomonas alcaligenes mutants lecithin solubilization Tn5.

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Screening of Highly Effective Sinorhizobium meliloti Strains for 'Vector' Alfalfa and Testing of Its Competitive Nodulation Ability in the Field

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Pedosphere 2007年第2期17卷 219-228页

作者： ZENG Zhao-Hai CHEN Wen-Xin HU Yue-Gao SUI Xin-Hua CHEN Dan-Ming College of Agronomy and Biotechnology China Agricultural University Beijing 100094 （China） College of Biology/Key laboratory of Agro-microbial Resource and Application Ministry of Agriculture China Agricultural University Beijing 100094 （China）

Seventeen Sinorhizobium meliloti strains from seven provinces in china were used to screen highly effective strains for alfalfa cultivar in a greenhouse study and their symbiotic relationship and competitive ability were studied in the field. CCBAU30138 was the most effective strain, as evidenced by increase in dry weights. A field experiment showed that the inoculation of alfalfa with CCBAU30138 resulted in increases of 11.9% and 19.6% of dry matter production and crude protein production, respectively, in forage of monocultured plants. The total dry matter yields of alfalfa and tall fescue in binary culture were increased by 16.3% by inoculation of alfalfa with this strain. These results showed that S. rneliloti strain CCBAU30138 was an effective inoculant both in the greenhouse and in the field. The analysis of randomly amplified polymorphic DNA （RAPD） by polymerase chain reaction （PCR） from nodule extracts showed that the strain CCBAU30138 had high competitiveness in the field. It occupied 47.5% of nodules in alfalfa monoculture and 44.4% of nodules in alfalfa-tall fescue binary culture after 20 weeks of growth. In conclusion, a simple system to select highly effective and competitive symbiotic strains specific to alfalfa was established. Using this system, a *** suitable for the alfalfa cultivar ‘Vector＇ grown in Wuqiao County of Hebei Province was obtained.

关键词： alfalfa inoculant selection Sinorhizobium meliloti tall fescue

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Invasive plant Ambrosia artemisiifolia *** the soil microbial community:interactions and implications for native plant performance and ecosystem function

Invasive plant Ambrosia artemisiifolia *** the soil microbia...

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第三届全国生物入侵大会

作者： Li Hui-na,Liu Wan-xue,Wan Fang-hao State Key laboratory for Biology of Plant Diseases and Insect Pests,institute of Plant Protection, chinese academy of Agricultural sciences,beijing 100094,china

Plant invasions present a serious threat to native ecosystem structure and *** is known about the role of rhizosphere soil microbial community in facilitating or resisting the spread of invasive species into native plant *** examined if invasive annual plant Ambrosia artemisiifolia (common ragweed) had changed the soil microbial community composition as they invaded and whether invasion-induced changes in the soil community affected native plant *** field experiments

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嗜酸热硫化叶菌麦芽寡糖基海藻糖合酶基因的克隆和表达

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生物工程学报 2001年第3期17卷 339-341页

作者：王辉陈炜吴襟金城中国科学院微生物研究所酶学研究室北京100080 中国科学院微生物研究所微生物资源前期开发国家重点实验室北京100080

The gene of MTSase (maltooligosyltrehalose synthase) from \%Sulfolobus acidocaldarius\% ATCC49426 was amplified by *** primers were designed according to the published sequence of homologous gene from \%Sulfolobus acidocaldarius \%*** gene was inserted into the plasmid pBV220 and the resultant recombinant plasmid pBV220\|GT was transformed to \%***\% DH5α.The activity of recombinant enzyme was about 10u/g(wet cell).In order to improve the expression level of target protein,some nucleotides in the 3′ and 5′ of the gene were modified to optimize the second structure of mRNA by PCR amplification using the new primers devised according to the biosoftware *** a result,the activity of recombinant enzyme increase to 19.8u/g(wet cell).Then,the helping plasmid pUBS520 which carried the gene encoding the tRNA of rare codons AGG and AGA was transformed to the recombinant *** it took little effect.

关键词：麦芽寡糖基海藻糖合酶嗜酸热硫化菌基因克隆表达大肠杆菌

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Contribution of Root and microbial Respiration to Soil CO_2 Efflux and Their Environmental Controls in a Humid Temperate Grassland of Japan

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Pedosphere 2009年第1期19卷 31-39页

作者： WANG Wei FENG Jiang T. OIKAWA Department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 （China） School of Urban and Environmental sciences Northeast Normal University Changchun 130024 （China） institute of Biological sciences University of Tsukuba Tsukuba Ibaraki 305-8572 （Japan）

Soil CO2 efflux, root mass, and root production were investigated in a humid temperate grassland of Japan over a growing season （Apr. to Sep.） of 2005 to reveal seasonal changes of soil CO2 efflux, to separate the respective contributions of root and microbial respiration to the total soil CO2 efttux, and to determine the environmental factors that control soil respiration. Minimal microbial respiration rate was estimated based on the linear regression equations between soil CO2 effiux and root mass at different experimental sites. Soil CO2 efflux, ranging from 4.99 to 16.29 μmol CO2 m^-2 s^-1, depended on the seasonal changes in soil temperature. The root mass at 0-10 cm soil depth was 0.82 and 1.27 kg m^-2 in Apr. and Sep., respectively. The root mass at 0-10 cm soil depth comprised 60% of the total root mass at 0-50 cm soil depth. The root productivity at 0-30 cm depth varied from 8 to 180 g m^-2 month^-1. microbial and root respiration rates ranged from 1.35 to 5.51 and 2.72 to 12.06μmol CO2 m^-2 s^-1, respectively. The contribution of root respiration to the total soil CO2 efflux averaged 53%, ranging from 33% to 72%. The microbial respiration rate was exponentially related to soil temperature at 10 cm depth （R^2 = 0.9400, P = 0.002, n = 6）, and the root respiration rate was linearly related to the root production at 0-30 cm depth （R2 = 0.6561, P = 0.042, n = 6）.

关键词： grasslands microbial respiration root production root respiration

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