纤维素-三(3,5-二甲基苯基氨基甲酸酯)涂敷氧化锆手性固定相的制备和色谱评价

制备并表征了涂敷纤维素 三 (3,5 二甲基苯基氨基甲酸酯 ) ZrO2 手性固定相。以正己烷 /异丙醇为流动相 ,研究了正相色谱条件下手性固定相对几类光学异构体的手性拆分能力。实验结果表明 :氧化锆载体表面的碱性性质对光学对映体的手性拆分有很大影响 ;在常用流动相条件下 ,酸性对映体被完全滞留 ;纤维素 三 (3,5 二甲基苯基氨基甲酸酯 ) ZrO2 手性固定相对于中性及碱性对映异构体的分离呈现出较好的手性拆分能力。

Study on the Fermentation Conditions of a Mucopolysaccharide-producing Bacterium LV-1

bacterium LV-1 which isolated from soil sample were studied bacterium was isolated by serial dilution method, the effects of carbon source, nitrogen source, the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions. [ Result] The physicochemical properties showed that the polysaccharide was water-soluble, but insoluble in organic solvents including ethanol, butanol, and chloroform. It was neutral polysaccharide with negative charge and without reducing terminal. The pH of its solution was pH =7.5. There were no protein, fructose, uronic acid, sulphate and starch-like structure included in po/ysacchadde molecules. The optimum fermentation conditions for po/ysaccharide produc- tion were 3% mannitol as carbon source, 0.25% yeast extract as nitrogen source, culture temperature 28 ~（3 and pH =7.5. [Coadu^en] The re- search could provide basis for development and utilization of LV-1 and industrialized production of mucopolysaccharide.

Acidthiobacillus ferrooxidans中磁小体的提取(英文)

At.f和趋磁细菌在生理特性和生长环境有一定的相似性,而且镜检发现At.f具有趋磁性,所以本文采用了趋磁细菌中磁小体的提取方法尝试提取At.f中的磁小体,用超声波破碎At.f后,以磁铁吸取其体内的磁性颗粒,经过检测,发现其体内确实存在含铁元素的磁性颗粒。提取粗样品经过电镜分析,证实其体内存在着少量由脂质包裹的磁小体。磁小体悬浮液经过蔗糖密度梯度离心纯化后,对其作透射电镜,可以清晰的看到磁小体。实验结果表明,At.f体内存在少量的磁小体,正是由于磁小体的存在,才使得At.f在外加磁场作用下发生磁生物效应。这是首次发现从酸性矿坑水分离的At.f具有趋磁性,并从中提取到了磁小体,可以利用At.f的趋磁性将其按照不同磁性进行分离,从而获得活性高的、对不同磁性矿物有特异性的高效浸矿菌种。

Isolation and Screening of Black Spot-Resistant Endophytic Fungi Strains from Rosa chinensis

[Objective] This study aimed to isolate and screen black-spot-resistant en- dophytic fungi strains. [Method] Various species of healthy Rosa chinensis were col- lected from Xi＇an, Xianyang, Baoji and Weinan City in Shaanxi Province. Endophytic fungi was isolated from stems and leaves, and purified by 2-3 times of inoculation to screen endophytic fungi antagonistic to Marssonina rosae with modified punching method. [Result] Samples collected from Xianyang exhibited the highest colonization rate and isolation rate; endophytic fungi strains isolated from stems presented the highest colonization rate and isolation rate compared with leaves. A total of 67 en- dophytic fungi strains were isolated from Rosa chinensis, including 3 black spot-re- sistant strains which were all derived from Baoji. [Conclusion] This study laid the foundation for further screening candidate strains of biocontrol fungi and environ- ment-friendly fungal biological control.

Recent Advances in Separation of Bioactive Natural Products

Bioactive natural products are a main source of new drugs,functional foods and food additives.The separation of bioactive natural products plays an important role in transformation and use of biomass.The isolation and purification of bioactive principle from a complex matrix is often inherent bottleneck for the utilization of natural products,so a series of extraction and separation techniques have been developed.This review covers recent advances in the separation of bioactive natural products with an emphasis on their solubility and diffusion coefficients,recent extraction techniques and isolation techniques.This overview of recent technological advances,discussion of pertinent problems and prospect of current methodologies in the separation of bioactive natural products may provide a driving force for development of novel separation techniques.

Isolation and characterization of bioactive fungi from shark Carcharodon carcharias' gill with biopharmaceutical prospects

Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi from the gill of a shark （Carcharodon carcharias）. A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial, pesticidal, and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit （ITS-LSU） rDNA-sequence BLAST comparison. Four genera, Penicillium, Aspergillus, Mucor, and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fimgi found in a shark＇s gills, revealing their biopharmaceutical potential. To the best of our knowledge, this is the first study characterizing shark gill fungi and their bioactivity.

Isolation and characterization of Acidithiobacillus caldus from several typical environments in China

Six strains of moderately thermophilic sulfur-oxidizing bacteria were isolated from several different typical environments in China. The identities of the isolates were confirmed by analyses of their 16S rRNA genes, and some key physiological traits. The isolates are Gram negative, rod-shaped bacteria, their optimal temperature and pH value for growth are 45-50℃ and 2.5-3.5 respectively. They are autotrophic and used elemental sulfur, sodium thiosulfate and potassium tetrathionate as electron donor, while a little glucose stimulated their growth. 16S rDNA sequences analysis reveals that the strains are phylogenetically clustered to Acidithiobacillus caldus.

Isolation, identification, and cytotoxicity of a new isobenzofuran derivative from marine Streptomyces sp. W007

A new isobenzofuran derivative( 1) was isolated from the marine Streptomyces sp. W007 and its structure was determined through extensive spectroscopic analyses, including 1D-NMR, 2D-NMR, and ESI-MS. The absolute configuration of compound 1 was determined by a combination of experimental analyses and comparison with reported data, including biogenetic reasoning, J-coupling analysis, NOESY, and 1 H- 1 HCOSY. Compound 1 exhibited no cytotoxicity against human cells of gastric cancer BGC-823, lung cancer A549, and breast cancer MCF7.

Physiological Characteristics of Rhizobia Isolated from Retama raetam （Forsk） and Lupinus various （L.） Indigenous to Libyan Desert

A total of 20 rhizobial isolates obtained from root-nodules of Retama raetam （Forsk） and Lupinus various （L.） were studied for their ability to tolerate local environmental and chemical stresses. Six fast and one slow growing reference strains were included for comparison. Numerical analysis showed that the reference strains were separated from test isolates. The majority of isolates displayed a high tolerance to extreme temperatures; some even grew at 48 ℃ and grew at alkaline and acid pH. Regarding tolerance to salinity on agar medium, the majority of the isolates grew at 6% NaCl, but some isolates from Lupinus various were more resistant, grew even at 8% NaCl. Most isolates were resistant to heavy metals, but were sensitive to most antibiotics tested.

Isolation and Properties Characterization of Biosurfactant Synthesized by Pyrene Degrading Bacillus subtilis C19

Bacillus subtilis strain C19, capable of ulilizing pyrene as a sole of carbon and energy, was isolated from marine Indonesian Archipelago. In biodegradation of pyrene by B. subtilis C19, various metabolites was isolated and identified by chromatographic and spectral analyses. Lipopeptide biosurfactant was produced and it has stable emulsification activity. Biosurfactant was produced for enhancing pyrene uptake and bioavaibility. After 30 days incubation, there were no toxic metabolite and biodegradation of pyrene was already complete （only 0.02% undegradable metabolite）. Therefore, this strain is suitable for PAHs （polyaromatic hydrocarbons） contaminated environment recovery.

Effect of Temperature Variation on the Separation of Sesamin and Sesamolin by Simulated Moving Bed

In this work, sesamin and sesamolin is separated and purified by SMB （simulated moving bed） chromatography. Purity of sesamin and sesamolin can reach 99.2% and 99.9 %, and they can be recovered by 99.9% and 99.4%, respectively. Concentrations of the extract and raffinate was monitored and periodical change of the concentration was observed on experiment. Effects of non-linear adsorption, dead volume, and temperature on the separation are reviewed by the triangle theory to explain the periodical change of concentration. It is found that dead volume has little effect, and temperature fluctuation significantly affects thc separation by SMB. The temperature seriously affects the robust operation of SMB due to the change of Henry＇s constant, which will change the selectivity and restrain the productivity. Although the productivity in this study is only 0.0416 g/L-hr, the cost of the stationary phase used in this study is much lower than that of packed in analytical column. By using this stationary phase, the authors are still able to separate the mixture of sesamin and sesmolin. This will economically attract attention for the application of SMB to purify bioactive compounds on developing botanical drugs.

Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

Magnetotactic bacteria have become a hot spot of research in microbiology attracting inten-sive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fas-tidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in diameter of 100nm, and consist of Fe and Co shown on energy dis-persive X-ray spectrum. The biological and physiological characteristics of this bacterium were also de-scribed. The colour of YSC-1 colony is white in small rod. The gram stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

Effect of bubbles addition on teetered bed separation

To improve the separation efficiency of a conventional Teetered Bed Separator(TBS) in beneficiation of fine coal with a wide size range,an Aeration TBS(A-TBS) was proposed in this investigation.The bubbles were introduced to A-TBS by a self-priming micro-bubble generator.This study theoretically analyzed the effect of bubbles on the difference in hindered settling terminal velocity between different density particles,investigated the impact of superficial water velocity(V_(SW)) and superficial gas velocity(V_(Sg)) on bed fluidization,and compared the performance of the TBS and A-TBS in treating 1-0.25 mm size fraction particles.The results show that the expansion degree of fluidized bed which was formed by different size particles or has different initial height,is increased by the introduction of bubbles.Compared with the TBS,at the same level of clean coal ash content,the A-TBS shows an increase in the combustible recovery of clean coal,ash content of tailings,and practical separation density by 5.26%,6.56%,and 0.088 g/cm3 respectively,while it shows a decrease in the probable error(E_p) and V_(SW) by 0.031 and 3.51 mm/s,respectively.The addition of bubbles at a proper amount not only improves the separation performance of TBS,but also reduces the upward water velocity.

Occurrence and Antibiotic Susceptibility Profile of Streptococcus spp. Isolated from Ewe＇s Milk

The purpose of this study was to determine the occurrence and antimicrobial resistance of Streptococcus spp. isolated from fresh ewe＇s milk and consequently to draw conclusions concerning the health condition of the animal flocks and the current trends of antibiotic use in small ruminants. A total of 77 mountainous sheepfolds were investigated representing 10% of all transhumant sheep and goats flocks in the area. Duplicate milk samples were collected from January to February transferred to the laboratory and analyzed for the presence of Streptococcus spp. by using the serial dilution method and plating on the surface of Slanetz and Bartley agar. The isolates were tested against nine antimicrobial agents with the Kirby-Bauer disk diffusion method. The results showed that Streptococcus spp. occurred in 84.4% of the samples and in counts ranged between 1.8 log CFU/mL and 4.6 log CFU/mL. Concerning susceptibility, only 1.3% of the isolates were resistant to all antimicrobials while 27.3% were fully susceptible. Resistance to cefepime was the most common （93.1%） observation followed by resistance to ampicillin （82.1%）, ciprofloxacine （58.3%） and meropenem （51.9%）. The isolates were vancomycin susceptible at a rate of 83.6%. Multidrug resistance to at least three antibiotics was observed to be 22.1% of Streptococcus spp.. Given the prevalence of Streptococcus spp. and the elevated resistance of isolates to various antibiotics it is concluded that further examinations and even interventions are required in order to pertain the appropriate animal health and milk quality.

The Biological Activity of Some Bacteria as Biocides to Protect Sesame Crop （Sesamum indicum） from Fungi Diseases

Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.

Qualitative and Quantitative Changes in Biochemical Constituents in the Rice Plant Treated with Different Xenobiotics

Experiments were conducted at Entomology division of Directorate of Rice research to study the qualitative and quantitative changes in biochemical constituents in the rice plant treated with different xenobiotics, viz. insecticides like deltamethrin, imidacloprid, herbicide like 2,4-Dichlorophenoxyacetic acid, fungicide like carbendazim, green manure Calotropis gigantea leaves, botanicals like Neem Seed Powder and fertilizer urea along with control plants of TN1, PTB33 and Swama varieties comprising of total 15 treatments. Application of butachlor, carbendazim, deltamethrin and excessive nitrogen fertilization resulted in increased population build up of brown plant hopper （BPH）. Significantly, lower honeydew excretion （13 mme area） in the BPH nymphs was observed on resistant PTB33 variety compared to susceptible TN1 and Swarna varieties （116 and 110 mm2 respectively）. In susceptible TN1 variety, the sucrose content was significantly higher （9.35 mg/g tissue） compared to BPH resistant PTB33 （5.32 mg/g tissue）. The BPH resistant PTB33 variety exhibited significantly lower free amino acid content （1.23 mg/g tissue） as compared to TN1 （2.51 mg/g）. The C/N ratio was comparatively high in the resistant PTB33 alone （4.32）, but was low in PTB33 applied with 2,4-D ＋ carbendazim （2.73）, 2,4-D ＋ imidacloprid ~ carbendazim （2.3）, excess urea fertilizer （2.18）. The total phenol contents measured in resistant PTB33 （7.5 mg/g dry wt）, susceptible TN1 （5.865 mg/g dry wt） and the popular variety Swarna （5.57 mg/g dry wt） were almost same and no statistical difference was observed. Further, treatment of these varieties with different xenobiotics and botanicals also did not significantly alter their total phenol content. However, the phenol content of the resistant PTB 33 alone and treated with xenobiotics was higher compared to the susceptible TN 1 and Swarna varieties alone and treated with xenobiotics. The plant biochemical constituents such as free amino acids, sucrose were lower in untreated resistant PTB33 compared to susceptible TN1, and PTB33 treated with urea and deltamethrin. The high feeding rate and population build up on the susceptible variety TN1 is positively correlated with high quantities of sucrose, free amino acids and lower quantities of phenols and low C/N ratio.

Endophytic Fungi Isolated from Mangrove （Rhyzopora mucronata） and Its Antibacterial Activity on Staphylococcus aureus and Escherichia coli

Disc diffusion method was used to investigate the antibacterial activity of methanol extract of five endophytic fungi isolated from mangrove （Rhizopora mucronata） on Staphylococcus aureus ATCC 9144 and Escherichia coli ATCC 8739, Fungi were isolated from leaf, stem and root of R. mucronata. Potato dextrose agar and potato dextrose broth were used for fungi purification and fermentation. Fungal metabolites were extracted with methanol （1 ： 1 v/v） for 24 h before vacuum evaporated to yield the crude extracts. Antimicrobial activity test was done according to the Kirby-Bauer test. The inhibition zone around each disc was considered to measure antibacterial activity of endophytic fungi. Only three endophytic fungi showed inhibition activity on S. aureus ATCC 9144 and two endophytic fungi showed inhibition on E. coil ATCC 8739. The results suggested that the extracts have a high potential for enteric diseases treatment caused by foodbome pathogen.

Inhibition of protein tyrosine phosphatase 1B activity by triterpenes isolated from Aceriphyllum rossii

An organic layer prepared from the seed of Aceriphyllum rossii was studied to identify the active compounds for protein tyrosine phosphatase 1B（PTP1B） inhibition.Bioassay guided fractionation resulted in the isolation of PTP1B inhibitory activity of triterpenes（1-4）.These four compounds were identified as aceriphyllic acid C（1）,aceriphyllic acid D（2）,aceriphyllic acid E（3） and aceriphyllic acid F（4）.The isolated 1-4 compounds inhibited PTP1B with IC50 values ranged from（2.1±1.5） μmol/L to（11.2±2.5） μmol/L.Kinetic analysis of PTP1B inhibition by aceriphyllic acid C（1） and aceriphyllic acid D（2） suggested that oleanane-type triterpenes inhibited PTP1B activity in a mixed-type manner.

Design criteria for tetradentate phenanthroline-derived heterocyclic ligands to separate Am(Ⅲ) from Eu(Ⅲ)

To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) were constructed and their complexation behaviors with Am(ⅡI) and Eu(ⅡI) were systematically investigated by density functional theory(DFT) coupled with relativistic small-core pseudopotential. In all the 1:1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms(N1 and N1′) of the phenanthroline skeleton and the other two nitrogen atoms(N2 and N2′) of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am(ⅡI) are larger than those of Eu(ⅡI). Additionally, the negative ΔΔGAm/Eu value for the reaction of [M(H2O)4-(NO3)3] + L → ML(NO3)3 + 4H2 O indicates that the complexation reaction of Am(ⅡI) is more energetically favorable than that of Eu(ⅡI); this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA(ⅡI) extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am(ⅡI) over Eu(ⅡI) follows the order of BTPhen > BBizPhen > BPyPhen > BPzPhen.

Nanoseparation-lnspired Manipulation of the Synthesis of CdS Nanorods

CdS nanorods have been sorted by length using a density gradient ultracentrifuge rate separation method. The fractions containing longer rods showed relatively stronger oxygen-related surface trap emission, while the shorter ones had dominant band-edge emission. These results suggest that the final length distribution of CdS nanorods is not a result of random nucleation and growth, but is related to the local synthesis conditions. Inspired by these findings, different synthesis environments （N2, air, and 02） have been employed in order to tailor the length distribution. In addition to the rod length, the photoluminescence properties of CdS nanorods can also be manipulated. Increasing the oxygen partial pressure significantly changed the growth behavior of CdS nanorods by improving the anisotropic growth.