检索结果-南通市图书馆

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, {2. 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 {2. 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, 12.9 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 2.℃ and 2.℃ ( 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.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanism of cadmium resistance and adsorption of a yeast strain Rhodotorula sp. Y11

引用

Science china Earth sciences 2005年第Z2期48卷 262-268页

作者： yuan hongli, {2. Zhijian, WANG Nengfei & huang huaizeng college of biological sciences, key laboratory of Agro-microbial resource and {12., ministry of agriculture, china agricultural university, beijing 100094, china National Research Center of Geoanalysis, beijing 100037, china college of biological {2. 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

The mechanism of cadmium resistance of a yeast strain Rhodotorula sp. Y11 isolated from mine soil was investigated. We found that the yeast cells treated with different methods showed different cadmium-adsorption models. Grown in medium supplied with 100 mg/L of cadmium, 3.2.% of the cell-absorbed cadmium was accounted in the cytoplasm. However, only 1% was taken into the cytoplasm and 99% was bound to the cell wall using the lyophilized biomass to adsorb cadmium in double distilled water. Treatments with alkali, ethanol-chloroform and proteinase showed different influences on the biosorption of whole cells and isolated cell walls. FT-IR analysis showed that acetyl of chitin was the active compound in the cells to absorb cadmium. The production of Metallothioneins, proteins related to the resistance to heavy metal in yeast, was evidently induced by cadmium, achieving 638.8 μg/g wet weight, which was about 85 folds higher than that in the uninduced biomass and was also much higher than that reported previously. The molecular weight of Metallothioneins was 6500 Da estimated by SDS-PAGE.

关键词： cadmium, adsorption, Rhodotorula sp., cell wall, Metallothionein.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Phenanthrene-degrading pathway of Agrobacterium sp. Phx1

引用

Science china Earth sciences 2005年第Z2期48卷 269-275页

作者： ZHANG Lei, yuan hongli, WANG S{2.qing & {2. huaizeng college of biological sciences, key laboratory of Agro-microbial resource and {12., ministry of agriculture, china agricultural university, beijing 100094, china National Research Center of Geoanalysis, beijing 100037, china college of biological {2. 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

The metabolic pathway of phenanthrene-degrading strain Agrobacterium sp. Phx1 was investigated. Phx1 almost was able to transform 100 υg/mL of phenanthrene completely in 1 day in broth media of beef extract-peptone (BP), Luria-Bertani (LB) and mineral salts media (MS), and LB and BP could promote the growth and degradation efficiency of Phx1. The GC-MS was employed to analyze the metabolites of the 1st, 3rd, 7th days of phenanthrene degradation in MS. As a result, the 1-Hydroxy-2.naphthoic acid (1H2.) and 1-naphthol (NOL) were detected in the metabolites of the 1st day. Only NOL was observed on the 3rd day and it disappeared on the 7th day. The accumulated NOL did not pertain to the defined pathway of phenanthrene degradation by bacteria. The further HPLC study confirmed the finding in GC-MS analysis and found the production of catechol (CAT) from o-phthalic acid (OPA) in the phenanthrene metabolizing, which has never been reported in the defined degrading pathways. This production was also evidenced by the production of CAT using OPA as substrate. All of our results showed that the Agrobacterium sp. Phx1 had a novel phenanthrene-degrading pathway.

关键词： Agrobacterium, phenanthrene, metabolic pathway, 1-naphthol, o-phthalic.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

引用

Science china Earth sciences 2005年第z2期48卷 276-284页

作者： QU Jianhang, yuan hongli, {2. huaizeng & WANG Entao college of biological sciences, key.laboratory of Agro-microbial resource and application,{12., china agricultural university, beijing 100094, china National Research Center of Geoanalysis, beijing 100037, china Escuela Nacional de Ciencias Bioldgicas, Instituto Politecnico Nacional, Mexico D. F. 11340, Mexico college of biological {2. 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 Escuela Nacional de Ciencias Biológicas Instituto Politécnico Nacional México D. F. 11340 México

In this study, DNAs were extracted from sediment samples at depths of 5, 35, and 69 cm from eutrophic Guanting reservoir, china. 16S rDNAs were amplified by PCR and clone libraries were constructed. The depth-related distribution of bacterial community in the sediment was characterized by using amplified 16S rDNA restriction analysis (ARDRA) and sequencing of the dominant clones. The results indicated that species diversity in the sediment of Guanting reservoir was rather high with the Shannon-Wiener index about 5.8. Bacterial richness varied in different depths: the highest in the sample of 35 cm in depth; followed by the sample of 5 cm in depth; and the lowest bacterial richness in the sample of 69 cm. Dominant species from the three samples were different although there were some common clones. Phylogenetic analysis showed that all of the dominant clones in the three layers were uncultured bacteria and distantly related to the previously reported species in beta or gamma subclass of proteobacteria, including bacterial groups that have the ability to degrade aromatic hydrocarbons, n-alkanes, chlorinated organic compounds, or to accumulate polyphosphate, etc. Changes of depth-related bacterial community in the Guanting reservoir sediment might reflect the pollution history and the water quality of the reservoir. In addition, the cloned sequences from the Guanting reservoir sediment were all different from the presently reported ones, indicating that there were some particular bacteria in that environment.

关键词： Guanting reservoir, sediment, bacterial community, 16S rDNA, eutrophication.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：