摘要:
基于微生物诱导碳酸钙沉积的岩土工程加固技术是一种环境友好的新技术。碳酸钙矿化菌是该技术应用的前提。为获得具有诱导碳酸钙沉积能力的菌株,采用选择性富集培养、平板分离方法从土壤中分离得到了一株具有尿素分解能力的菌株,细菌诱导产生的沉积物检测结果表明该菌株具有诱导碳酸钙沉积能力。通过形态学、革兰氏染色和16 S rDNA序列同源性分析鉴定该菌株为巴斯德芽孢杆菌。
摘要:
In order to develop an effective and economical method for removing U(VI) from the low concentration radioactive wastewater with the U(VI) concentration of less than 1 mg L<sup>-1</sup>, the biomass of Aspergillus niger was prepared and modified with ethylenediamine, and the biosorption of uranium from the low concentration radioactive wastewater by the unmodified and the modified biomasses was investigated in a batch system. The modified biomass exhibited the adsorption efficiency of 99.25 % for uranium under the optimum conditions that pH was 5.0, the contact time was 150 min, and the biosorbent dose was 0.2 g L<sup>-1</sup>. The adsorption fitted well to Langmuir isotherm, and the maximum sorption capacity of the modified biomass for U(VI) was determined to be 6.789 mg g<sup>-1</sup> which increased by 36.45 % compared with the unmodified biomass. The adsorption kinetics was better depicted by pseudo-second-order kinetic model. The Gibbs free energy change (ΔG <sup>0</sup>), enthalpy change (ΔH <sup>0</sup>), and entropy change (ΔS <sup>0</sup>) showed that the process of U(VI) adsorption was spontaneous, endothermic, and feasible. The changes in the groups, morphology, and the presence of U(VI) on the surface of the adsorbents which were characterized by FT-IR, SEM, and EDS, demonstrated that the U(VI) was successfully adsorbed onto the modified biomass. Moreover, the UO<inf>2</inf> <sup>2+</sup> absorbed on the modified biomass can be released by 0.1 mol L<sup>-1</sup> HNO<inf>3</inf> with high desorption efficiency of 99.21 %. The results show that the modified biomass can remove U(VI) from low concentration radioactive wastewater more effectively than the unmodified biomass.
摘要:
Campylobacter species.are phenotypically diverse in many aspects including host habitats and pathogenicities, which demands comprehensive characterization of the entire Campylobacter genus to study their underlying genetic diversification. Up to now, 34 Campylobacter strains have been sequenced and published in public databases, providing good opportunity to systemically analyze their genomic diversities. In this study, we first conducted genomic characterization, which includes genome-wide alignments, pan-genome analysis, and phylogenetic identification, to depict the genetic diversity of Campylobacter genus. Afterward, we improved the tetranucleotide usage pattern-based naïve Bayesian classifier to identify the abnormal composition fragments (ACFs, fragments with significantly different tetranucleotide frequency profiles from its genomic tetranucleotide frequency profiles) including horizontal gene transfers (HGTs) to explore the mechanisms for the genetic diversity of this organism. Finally, we analyzed the HGTs transferred via bacteriophage transductions. To our knowledge, this study is the first to use single nucleotide polymorphism information to construct liable microevolution phylogeny of 21 Campylobacter jejuni strains. Combined with the phylogeny of all the collected Campylobacter species based on genome-wide core gene information, comprehensive phylogenetic inference of all 34 Campylobacter organisms was determined. It was found that C. jejuni harbors a high fraction of ACFs possibly through intraspecies recombination, whereas other Campylobacter members possess numerous ACFs possibly via intragenus recombination. Furthermore, some Campylobacter strains have undergone significant ancient viral integration during their evolution process. The improved method is a powerful tool for bacterial genomic analysis. Moreover, the findings would provide useful information for future research on Campylobacter genus.
作者机构:
[孙静; 丁德馨; 胡南; 李广悦; 王永东] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China
通讯机构:
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构:
[胡南; 丁德馨; 李广悦; 王永东; 李乐; 郑济芳] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China
通讯机构:
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
会议名称:
中国核学会2011年年会
会议时间:
2011-10-11
会议地点:
贵阳
会议论文集名称:
中国核学会2011年年会论文集
关键词:
铀;水生植物;植物修复;满江红
摘要:
采用水培实验,研究了浮叶植物野生水葫芦(Eichhornia crassipes)、漂浮植物浮萍(Lemna minor L)、满江红(Azolla imbircata)、沉水植物菹草(Potamogeton crispus)、挺水植物空心莲子草(Alligator Alternanthera Herb)在初始铀浓度分别为0.15、1.50和15.00mg·L-1水中的生长状况及它们对水中铀的去除能力.结果表明,在21d的水培试验期内,满江红对铀表现出了最强的抗性,0.15、1.50和15.00mg·L-1的铀对满江红的生长抑制率分别只有4.56%、2.48%和6.79%,而满江红对水中铀的去除率分别达到了94%、97%和92%.进一步的试验表明,每1L水中种植7.5g满江红,可以获得最大的铀去除率,将初始铀浓度为1.25、2.50、5.00和10.00mg·L-1的水体降至国家排放标准(GB23727-2009)规定值(0.05mg·L-1)以下分别需要17、19、23和25d.研究结果为进一步开展铀污染水体植物修复的研究打下了基础.
作者机构:
[李广悦; 刘希涛; 丁德馨; 王永东; 胡南] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, Hunan, China;[刘希涛] Jiaojia Gold Mine, Laizhou 264000, Shandong, China
通讯机构:
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构:
[王永东; 李广悦; 丁德馨; 胡南; 邓钦文; 周支香] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, Hunan, China
通讯机构:
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构:
[刘玉龙; 胡南; 王有团; 王清良; 李广悦; 丁德馨; 王永东] Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, Hunan 421001, China
通讯机构:
[Ding, D.-X.] K;Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, , Hengyang, Hunan 421001, China
摘要:
The Huayuan River in Hunan Province in China is subject to ongoing mining activity with Mn extraction. In this study, the level and environmental significance of metals (including Mn, Cd, Pb, Cu, Zn, Ni and Fe) concentrations in the surface water and river sediments have been investigated along a 187 km reach of the Huayuan River. Using the X-ray fluorescence (XRF) analysis, we analyzed the characterization of metals in manganese sulphate waste residue (MSWR) deposited along the bank of Huayuan River. The speciation of metals in both sediment and MSWR was established using the BCR-three step sequential extraction procedure. In the water samples, the average concentrations of Mn, Cd and Pb exceeded the acceptable concentrations for drinking water in the WHO Guidelines for drinking water quality, Vol. 1, Recommendations, Geneva (2004) and Chinese (GB 5749-2006) guidelines, respectively. The average concentrations of Mn, Cd, Pb and Zn in the river sediments were found to be considerably higher than the corresponding world average shale values. The percentages of Cd (31.4%), Mn (31.1%), Zn (12.8%) and Pb (8.1%) associated with exchangeable and weak acid fraction in the sediments were higher than other metals. Mn (5.81%), Zn (0.208%), Pb (0.0292%) and Cd (0.0113%) were identified in MSWR by XRF analysis. The percentages of Mn, Cd, Zn and Pb associated with the exchangeable and weak acid soluble fraction in MSWR were 41.9%, 31.1%, 23.8% and 9.8%, respectively. The peak solute and sediment-bound metal concentrations were found at the sites of MSWR deposited along the bank of Huayuan River. The results suggested that MSWR deposited along the bank may have a closely relation with the metal pollution of Huayuan River. The results obtained may be useful to assess both short and long-term environmental impact of the MSWR deposited activities and support decisions for a future remediation of this river.
作者机构:
[丁德馨; 刘玉龙; 李广悦; 胡南; 王永东; 王有团] Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, Hunan, China
通讯机构:
Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构:
[丁德馨; 王有团; 李广悦; 王永东; 刘玉龙] Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China
通讯机构:
[Ding, D.-X.] K;Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, , Hengyang 421001, China