Methyl-branched poly(hydroxyalkanoate) biosynthesis from 13-methyltetradecanoic acid and mixed isostearic acid isomer substrates

Nonylphenol, the most abundant environmental pollutant with endocrine disrupting activity, is also toxic to plants and microorganisms, but its actual impact in the field is unknown. In this study, diversity of culturable soil microfungal and plant communities was assessed in a disused industrial estate, at three sites featuring different nonylphenol pollution. Although soil microfungal assemblages varied widely among the sites, no significant correlation was found with point pollutant concentrations, thus suggesting indirect effects of soil contamination on microfungal assemblages. The potential of indigenous fungi and plants to remove nonylphenol was assessed in mesocosm experiments. Poplar plants and a fungal consortium consisting of the most abundant strains in the nonylphenol-polluted soil samples were tested alone or in combination for their ability to reduce, under greenhouse conditions, nonylphenol levels either in a sterile, artificially contaminated sand substrate, or in two non-sterile soils from the original industrial area. Introduction of indigenous fungi consistently reduced nonylphenol levels in all substrates, up to ca. 70% depletion, whereas introduction of the plant proved to be effective only with high initial pollutant levels. In native non-sterile soil, nonylphenol depletion following fungal inoculation correlated with biostimulation of indigenous fungi, suggesting positive interactions between introduced and resident fungi. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

一株高抗汞细菌的分离鉴定及其抗性基因的克隆与表达

摘要：【目的】本研究旨在从重金属汞抗性细菌中分离鉴定汞抗性基因【方法】从北京凉水河河床底泥中分离抗汞细菌,采用16S rRNA基因序列分析结合生理生化特征对菌株进行鉴定。根据GenBank中已发表的多种抗汞细菌的merA基因序列设计引物,以抗性细菌基因组DNA为模板,扩增merA基因,并在大肠杆菌（Escherichia coli）BL21(DE3)表达。同时对表达菌株的重金属汞抗性进行测定。【结果】分离得到一株能在含HgCl2为70 mg/L的平板上生长良好的高抗汞细菌,编号为KHg2。16S rRNA     

抗菌免疫核糖核酸组份的分离及其活性测定

<正> 抗菌免疫核糖核酸(iRNA)已用于条件致病菌感染的临床治疗,并对其免疫活性做了全面的研究。现已证实iRNA能够诱导特异性抗体的产生和传递特异性的细胞免疫,并能诱生干扰素和白细胞间素Ⅰ、Ⅱ等淋巴因子和单核因子。但制备的iRNA是含有多种RNA种类的混合物,为明确各组份的免疫学功能,我们对iRNA进行了分离,并测定不同组份的免疫活性。     

Subcellular Distribution and Chemical Forms of Cadmium in the Medicine Food Homology Plant <i>Platycodon grandiflorum</i> (Jacq.) A.DC.

Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.     

用PCR法直接快速筛查重组阳性克隆

应用ＰＣＲ法快速筛查插入有苯丙氨酸脱氨酶ｃＤＮＡ重组阳性克隆。方法：用于ＰＣＲ扩增的引物是位于载体ｐＥＴ２３ｂ启动子处的Ｔ７启动子引物和位于目的基因ＰＡＬｃＤＮＡ３’端终止密码ＴＡＡ处的引物。以灭菌吸头挑一单菌落加入ＰＣＲ体系扩增。结果：在筛查的３个克隆中,有２个阳性克降,并且插入方向正确,经ＤＮＡ序列测定得到进一步证实。结论：以ＰＣＲ方法筛查重组阳性克隆,可以简便快速鉴定插入片段的大小和方面,不     

对虾白斑综合症病毒囊膜蛋白VP28的表达及其抗病毒感染作用

根据GenBank上WSSV囊膜蛋白基因vp28的序列,设计并合成引物,PCR扩增得到vp28基因,成功构建重组表达载体pET22b-vp28并转化大肠杆菌BL21(DE3)。基因工程菌株37℃IPTG诱导,表达产物经Western-blot和SDS-PAGE检测显示有与预期大小32kDa相符合的目的蛋白。用Ni2 -柱纯化的目的蛋白分别直接注射螯虾和包被饲料投喂螯虾,实验结果表明vp28在大肠杆菌中的表达产物有显著提高虾体抗WSSV感染力的作用,而且注射效果更好。     

Cocirculation of two transmission lineages of echovirus 6 in jinan, china, as revealed by environmental surveillance and sequence analysis

Enterovirus environmental surveillance on sewage from the city of Jinan, Shandong Province, China, was initiated in 2008. Thirty echovirus 6 (E6) strains-1 in 2008 and 29 in 2010-were isolated and identified. Most E6 isolates (n = 21) came from the sewage collected on August 2010, revealing high local E6 activity at that time. Interestingly, the VP1 sequences of most isolates, even from the same sewage, were not identical. Phylogenetic analysis of VP1 sequences revealed two lineages for these isolates, with 78.0 to 80.0% nucleotide identities with one another, 94.8 to 100.0% identity within the major lineage, and 92.7 to 98.5% identity within the minor one. The VP1 sequences of environmental isolates, clinical isolates from 1998 to 2010, and global E6 were subjected to evolutionary analysis using Bayesian phylodynamic methods. The inferred E6 VP1 ancestral sequence dated back to 1901 (range, 1873 to 1928) and evolved with 7.047 × 10(-3) substitutions per site per year. Shandong E6 segregated into three clusters, and the two environmental lineages belonged to clusters A and C, which originated in 2003 and 1992, respectively. The antigenicity analysis via neutralization assay confirmed great antigenic differences between Shandong isolates and a prototype strain. These findings underscore the value of continuous environmental surveillance and genetic analysis to monitor circulating enteroviruses in the population and give further insight into E6 evolution.     

微生物降解农药研究的新进展

农药尤其是化学农药中高毒、高残留、难降解的农药是重要的环境污染物,而利用微生物治理农药所造成的环境污染是一项有效的手段。从降解农药的微生物的种类、工程菌的构建、微生物降解农药的机理、降解特性、影响因素及应用效果等多方面综述了近年来的研究进展,并提出了微生物降解农药研究领域的发展趋势和有待进一步解决的一些突出问题。     

Dark septate endophyte (DSE) fungi isolated from metal polluted soils: Their taxonomic position, tolerance, and accumulation of heavy metals In Vitro

To understand the possible role of the plant root associated fungi on metal tolerance, their role in the uptake of heavy metals and the potential transfer of these metal ions to the plant, three strains of dark septate endophytic (DSE) fungi were isolated from a waste smelter site in southwest China, and one strain was isolated from a non-contaminated site. According to molecular phylogenetic analysis of the ITS 1-5.8S rDNA-ITS 2 gene regions and morphological characteristics, one is identified as Exophiala pisciphila, and the other three are non-sporulating fungi under the experiment condition with the nearest phylogenetic affinities to the Thysanorea papuana strain EU041814. Tolerance and accumulation abilities of the three DSE strains for metals were investigated in liquid culture. Minimum inhibitory concentrations (MIC) of Pb, Zn, and Cd were determined. It was demonstrated that the tolerance of the DSE strains varied between metal species and strains. The E. pisciphila strain is able to accumulate lead and cadmium over 20% and 5% of dry weight of biomass, respectively. Partial of the sequestrated metals can be washed with CaCh. Morphological and enzyme activity changes taking place in the presence of excessive Pb, Cd, and/or Zn also indicate that the mechanism of heavy metal tolerance and accumulation of the DSE strains would be a complex process. The findings indicated promising tolerance and accumulation of the DSE strains with potential values in metal cycling and restoration of soil and water system.