白云鄂博稀土矿区若干微生物培养特征探究

从白云鄂博稀土矿区分离到20株纯培养菌,对其个体形态、菌落特征、革兰氏染色反应和一系列生理生化特性进行了研究并作了初步鉴定。其中,细菌14株,11株鉴定到种,3株鉴定到属;放线菌5株均鉴定到种;真菌1株鉴定到种。同时,经相关试验还测得,20株菌中有极耐酸菌10株;极耐碱菌11株;既耐酸又耐碱菌6株;耐受pH值1～12的菌7株;20株菌都能耐受pH2;耐盐菌17株;耐冷菌20株;耐热菌3株;既耐冷又耐热菌3株。     

白云鄂博稀土矿区土壤中放线菌特征调查研究

利用稀释平板涂布法对白云鄂博稀土矿区土壤中放线菌进行了分离与形态观察,同时应用相似性指数、丰富度指数、多样性指数以及均匀度指数等生态学方法对该地区放线菌的生态学特征进行了分析,并在此基础上分别对所选放线菌的耐盐性、耐酸碱性、耐低温或高温以及耐高辐射性元素等耐性指标进行了调查研究.结果表明:①经纯培养及菌落颜色和形态观察...     

三株溶藻细菌胞外溶藻活性物质若干分离特性的研究

为了探索新分离到的3株溶藻细菌胞外溶藻活性物质的分离特性,选择了对水华鱼腥藻生长无抑制作用的淀粉培养基培养溶藻细菌.采用透析、乙醇沉淀、有机溶剂萃取、活性炭吸附与解吸等方法对其分离特性进行了研究.溶藻细菌L7的溶藻活性物质的分子量小于3.5 kD,溶藻细菌L8、L18的溶藻活性物质的分子量在3.5 kD～7 kD之间;3株溶藻细菌的胞外溶藻活性物质不能用乙醇沉淀法完全分离;3株溶藻细菌的溶藻活性物质具较好的亲水性和较强的极性,且都不能被活性炭吸附.     

七种我国昆虫病原线虫共生菌的分离与鉴定

昆虫病原线虫共生菌是一类具有广阔发展前景的生物防治资源,由于这类菌的分类鉴定工作起步晚,存在分类混乱和不系统的现象,在本土资源十分丰富的我国尤为突出.本文对本实验室分离的7个共生菌菌株进行了分类描述,建立了以生理形态,生化特征为分类基础,结合16 SrDNA序列分析的有效鉴定方法.     

稀土多元复合肥和三种稀土元素的遗传毒性研究

采用蚕豆根尖细胞微核技术,研究市售稀土多元复合肥和稀土元素镧、铈、铒的化合物对蚕豆根尖细胞的遗传毒性和细胞毒性。结果表明,稀土复合肥和三种稀土元素均可诱发微核效应,在一定浓度下可损伤细胞,影响根尖的正常生长,其中稀土复合肥的微核效应表现出明显的剂量-效应关系。稀土复合肥和稀土元素镧、铈、铒的化合物对蚕豆根尖细胞具有一定的遗传毒性作用和细胞毒性作用,在施用稀土微肥和使用稀土制品时应引起重视。 Abstract：This paper presents the study of genetic toxicity and cell toxicity that is give n by rare earth multi-element compound fertilizer and a chemical compound of rar e earth elements-La3＋、Ce4＋、Er3＋ in root tip cells of Vicia faba.The technique used is micronucleus in root tip cells of Vicia faba.The experiment statistical result shows that both the rare earth compound fertilizer and the three kinds of rare earth elements can cause micronucleus ef fect and under certain concentration,they can hurt cells, affect root tip gro wth .The micronucleus effect of the rare earth compound fertilizer shows a clear relation of dosage-effect. The conclusion is that rare earth compound fertilize r and the chemical compound of rare earth elements La3＋、Ce4＋、E r3＋cause certain genetic toxicity and cell toxicity effect to root tip cells of Vicia faba.Therefore a close attention should be paid when the rar e earth multi-fertilizer and other things made by rare earth are used.     

Biomineralization of Middle Rare Earth Element Samarium in Yeast and Bacteria Systems

Microorganisms play an important role in the mineralization of heavy metals in different environments. Previous studies have reported the phosphate mineralization of light (Ce) and heavy (Yb) rare earth elements with yeast. However, little is known about differences in the biomineralization process of middle rare earth elements (including Sm, Eu, Gd, Tb and Dy) by yeast and bacteria. We carried out a series of experiments to compare the sorption process of Sm by Saccharomyces cerevisiae (yeast), Pseudomonas fluorescens (gram-negative bacteria) and Bacillus subtilis (gram-positive bacteria) in initial pH 3, 4 and 5 solutions. The concentrations of Sm in exposure solutions decreased as a function of exposure time in all three systems, which revealed the accumulation of Sm by cells. In both yeast and bacteria systems, Sm(III) was mineralized to monazite(Sm) phase particles on cell surfaces at 5 days of exposure after a short-term adsorption process. In these three systems, nano-sized Sm phosphate formed more quickly on cell surfaces with higher pH exposure solutions. The formation of precipitation on bacterial cell surfaces was faster than in yeast. There were no significant differences in the sorption process of Sm between the two bacteria Pseudomonas fluorescens and Bacillus subtilis.     

New Arsenite-Oxidizing Bacteria Isolated from Australian Gold Mining Environments--Phylogenetic Relationships

Nine novel arsenite-oxidizing bacteria have been isolated from two different gold mine environments in Australia. Four of these organisms grow chemolithoautotrophically with oxygen as the terminal electron acceptor, arsenite as the electron donor, and carbon dioxide-bicarbonate as the sole carbon source. Five heterotrophic arsenite-oxidizing bacteria were also isolated, one of which was found to be both phylogenetically and physiologically identical to the previously described heterotrophic arsenite oxidizer misidentified as Alcaligenes faecalis . The results showed that this strain belongs to the genus Achromobacter . Phylogenetically, the arsenite-oxidizing bacteria fall within two separate subdivisions of the Proteobacteria . Interestingly, the chemolithoautotrophic arsenite oxidizers belong to the f - Proteobacteria , whereas the heterotrophic arsenite oxidizers belong to the g - Proteobacteria .     

Criticality of the Rare Earth Elements

Recent constraints on supplies of the rare earth elements (REEs) have led to concerns about their long‐term availability as well as the consequences that shortages would pose for modern technology. To assess this situation, we apply a comprehensive “criticality” methodology to the REE: lanthanum (La); cerium (Ce); praseodymium (Pr); neodymium (Nd); samarium (Sm); europium (Eu); gadolinium (Gd); terbium (Tb); dysprosium (Dy); holmium (Ho); erbium (Er); thulium (Tm); ytterbium (Yb); lutetium (Lu); and yttrium (Y). Assessments are made on national (U.S. and China) and global levels for the year 2008. Evaluations of each indicator are presented and the results plotted in “criticality space” on a 0 to 100 scale. Over the medium term (5 to 10 years), supply risk (SR) for all REEs is moderate with minimal variation (62.8 to 65.1). Over the long term (10 to 100 years), SR is low (42.1 to 49.2). Environmental implications scores, reflecting the economic allocation of environmental burdens, range from 4.2 for La to 34.4 for Lu. Eu, Er, and Dy have the highest vulnerability to supply restriction (VSR) at the global level (50.6, 49.2, and 47.4, respectively), whereas Sm has the lowest (15.1). This is mainly a reflection of their substitution potential. Similarly, at the national level for the United States and China, Eu and Sm have the highest and lowest VSR scores, respectively, although there are notable differences in scores among the REEs and between countries. Although China's export restrictions render REE supplies inadequate to meet demand at present, our analysis indicates a lower criticality for REEs over the longer term than for a number of other industrially used metals.     

Composition,Characteristic and Activity of Rare Earth Element-Bound Polysaccharide from Tea

The compositions and structural characteristics of rare earth elements-bound polysaccharides from tea (REE-TPS) were studied with the methods of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Gas Chromatography (GC) and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The results show that polysaccharide from tea (TPS) was a sort of glycoprotein and coordinated with Rare Earth Elements (REE) closely. The sugar fraction was composed of Rha, Ara, Xyl, Fuc, Glc, and Gal. There existed almost all natural amino acids with Glx, Asx, and Hyp as the major parts in the protein fraction. The REEs in REE-TPS were mainly composed of La, Ce, and Nd, especially, more than 75% of them was La. The coordination atom of the first coordination shell of La in REE-TPS was oxygen, the coordination number of which was 6, and the average distance between the atoms was 2.52 Å. The second shell was formed from sulfur atoms, the coordination number and the average distance were 3 and 2.91 Å, respectively. The bio-experiments show that REE-TPS could decrease the content of blood glucose in mice significantly.     

Mining Rare Associations between Biological Ontologies

The constantly increasing volume and complexity of available biological data requires new methods for their management and analysis. An important challenge is the integration of information from different sources in order to discover possible hidden relations between already known data. In this paper we introduce a data mining approach which relates biological ontologies by mining cross and intra-ontology pairwise generalized association rules. Its advantage is sensitivity to rare associations, for these are important for biologists. We propose a new class of interestingness measures designed for hierarchically organized rules. These measures allow one to select the most important rules and to take into account rare cases. They favor rules with an actual interestingness value that exceeds the expected value. The latter is calculated taking into account the parent rule. We demonstrate this approach by applying it to the analysis of data from Gene Ontology and GPCR databases. Our objective is to discover interesting relations between two different ontologies or parts of a single ontology. The association rules that are thus discovered can provide the user with new knowledge about underlying biological processes or help improve annotation consistency. The obtained results show that produced rules represent meaningful and quite reliable associations.     

三株芸豆叶际拮抗细菌的筛选与鉴定

以芸豆锈病病原菌[Uromyces appendiculatus(Pers.)Ung.]为指示菌,从芸豆叶际中筛选到3株具有明显拮抗效果的细菌,编号为SS2,L14b,NEW2。经过形态学观察,生理生化测定,16S rDNA序列及系统发育分析,初步鉴定SS2为短短芽孢杆菌(Brevibacillus brevis),L14b与NEW2为枯草芽孢杆菌(Bacillus subtilis)。SS2,L14b,NEW2的16S rDNA序列的Gen-Bank登录号分别为EU771078、EU771076和EU771079。