Search

To detect possible pathogenic virus(es) in woad (Isatis tinctoria) cultivated at Institute of Medicinal Plant Development in Beijing, reverse transcription(RT)-PCR was performed using total RNA of symptomatic woad leaves with primers for poty-, polero-, tobamovirus, broad bean wilt virus 2(BBWV2) and cucumber mosaic virus (CMV). A 657 bp fragment was amplified from symptomatic woad using CMV primers. Sequencing and BLAST analysis indicated that this fragment shared 99% nucleotide identity and 100% amino acid identity with CMV-Vi isolate. The isolate was named CMV-Isatis tinctorial (CMV-It). Phylogenetic analysis based on nucleotide sequences of CP genes showed that CMV-It clustered with CMV-K and belonged to subgroup I. To our knowledge, this is first identification of CMV in woad by RT-PCR and the CP gene was analyzed. This work provided data for research and control of woad mosaic disease.

Using electrochemical oxidation method treats the acid red 3R simulation wastewater, investigates the influence of current density, electrolyte concentration, pH-value and aeration and their interaction on the removal rate of chroma. Through the design of Box-Benhnken Design(BBD) and the response surface analysis, the influence sequence of all variables is current density > aeration > electrolyte concentration > pH-value, the influence sequence of all interaction is electrolyte concentration-aeration > current density-aeration ,electrolyte concentration-pH value > current density-pH value > pH value-aeration > current density-electrolyte concentration. Ultimately, the optimal value is 98.4915% under the condition of current density of 6.51mA/cm2,electrolyte concentration of 0.04mol/L,pH-value of 4.17 and aeration of 0.24m3/h.

By the static experiment, we studied the electrochemical oxidation process of simulated hydroquinone wastewater (concentration for 300mg•L-1) in the three-dimensional cell. Experimental inspected how various factors of the packing quality ratio, electrolysis voltage, supporting electrolyte concentration, and the initial pH value influence the effect of the removal of hydroquinone and CODCr. The results of the experiment clearly indicated with the increase of voltage applied the removal rate of hydroquinone and CODCr increased first and then decreased, finally and increased again. In the weak alkali conditions (pH=8.5), the removal rate of hydroquinone and CODCr is the highest, Electrolyte concentration and packing quality ratio to the effect of hydroquinone by electrochemical degradation is the larger. The results of the single factor analysis show that the most suitable processing conditions of simulated hydroquinone wastewater by bipolar electrocatalysis oxidation are the Na2SO4 concentration of 0.03mol•L-1, the electrolytic voltage of 6V, the initial pH value of 8.5, the packing quality ratio of 1:2. With this condition processing 3h, the removal rate of hydroquinone and CODCr reached 83.96% and 39.9%, respectively.

In diaphragm cell, by using the porous graphite as anode, ACF as the cathode, acid scarlet 3R as simulated wastewater, the experiment researched into the effect of current density, electrolyte concentration, aeration rate and the initial pH value on the color removal of wastewater. The results show that the decolourization efficiency increased gradually when the applied current density increases, but the trend will slow down when current density exceeds a certain value. The decolourization efficiency is proved to be first increases then decreases with increased electrolyte concentration and aeration rate, both excessively high and low electrolyte concentration are unfavorable to the removal of wastewater, however the aeration effect is smaller. The effect on decolorization is greater in acid condition than in alkaline condition. As the diaphragm, electrolyzer resistance increase, its average decolourization efficiency is lower than without diaphragm cell, and the decolourization efficiency of cathode area is significantly higher than the anode area.

Huoxiang (Agastache rugosa, family Labiatae) is used as a traditional Chinese medicine. In 2017, Huoxiang with stunted, chlorotic, and mosaic symptoms were found in Haidian District of Beijing, China. To identify the causal agent(s), total RNA of symptomatic leaves was extracted and further analyzed by high-throughput sequencing (HTS). Sequence analyses revealed nine contigs with high nucleotide sequence identity (93%–100%) with tomato yellow leaf curl virus (TYLCV) from the genus Begomovirus, family Geminiviridae and seventeen contigs with high nucleotide sequence identity (85%–100%) with cucumber mosaic virus (CMV) from the genus Cucumovirus, family Bromoviridae. To confirm the HTS results, RT-PCR was performed with TYLCV-specific primers and CMV-specific primers, respectively. Two fragments of 651 bp (GenBank accession No. MG775386) and 657 bp (MG754206) were obtained, respectively. Sequencing and BLASTn analysis revealed that the 651 bp fragment shared 100% nucleotide identity with TYLCV isolate ZJHZ (MF590742), and the 657 bp fragment shared 98.9% nucleotide identity with CMV strain K (AF127977). To our knowledge, this is the first report of TYLCV and CMV infecting A. rugosa.

Rotation, scaling and translation (RST) attacks can desynchronize the watermark detection so that many watermark systems failed. A geometrically robust image watermarking strategy based on Jacobi-Fourier moments (JFMs) is proposed. The Jacobi moments of the original image are first extracted as original moments; then the watermark image is embedded into the global or local area of the original image, and the Jacobi moments of the area are extracted. When the watermarked image is not attacked, the watermark can be retrieved by using the margin of the original moments and the moments of the embedded area. When it is attacked, the watermark can also be got in that way, and the original moments need to be transformed. It can be concluded that Jacobi-Fourier moments perform better than Zernike moments (ZMs) for small images. Meanwhile, the watermark is also robust to scaling and rotation as well as regular attacks such as added noises.

Constant laccase activities were detected in culture supernatant of newly isolated basidiomycete Trametes gallica. Tryptone and glucose have great effects on the production of laccase. Two laccase isoenzymes (Lac I and Lac II) produced by T. gallica were purified to homogeneity (51- and 50-fold, respectively) by gel filtration chromatography, anion exchange chromatography, and improved native PAGE, with an overall yield of 24.8%. Lac I and Lac II from this fungus are glycoproteins with 3.6% and 4% carbohydrate content, the same molecular masses (by SDS-PAGE) of 60 kDa, and the pI of 3.1 and 3.0, respectively. Native gel electrophoresis indicates that the two laccases have different migration ratios. Lac I and Lac II have the same optimal pH of 3.0 on 2,6-dimethoxyphenol (DMP), pH 2.2 on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and of pH 4.0 on guaiacol. The highest rate of ABTS oxidation for both laccases was reached at 70 degrees C. Both laccases are stable from pH 6 to 9, retaining 88-90% activity after 24 hr incubation, and show good stability when incubated at temperatures lower than 40 degrees C. The Km values of Lac I for ABTS, DMP, and guaiacol are 0.118 x 10(-2), 0.420, and 0.405 mM, respectively; the Km values of Lac II for ABTS, DMP, and guaiacol are 0.086 x 10(-2), 0.41, and 0.40 mM, respectively. Their N-terminal sequences are determined and show strong similarity with those from other basidiomycetes. Graphite-furnace atomic absorption analysis revealed that both laccases have four copper atoms per protein molecule, but they have no type I copper signal at around 600 nm and a type III copper signal near 330 nm. Cyanide, azide, and halides completely inhibit the enzyme activity, whereas EDTA has less inhibition.

Laccase production by the white-rot fungus Trametes gallica was studied, using twelve different media under static or shaking condition. The results indicated that organic nitrogen sources such as tryptone and peptone strongly improved laccase production. The application of an amino acid mixture and a lignin preparation also increased the formation of laccase, which was not observed in the presence of potato extract. Native polyacryl amide gel electrophoresis (PAGE) followed by laccase activity staining using guaiacol as the substrate was performed to analyze the laccase isozyme patterns under the different culture conditions employed. Zymograms revealed a total of twenty different laccase activity bands that appeared in individual patterns, dependent on the respective culture condition applied. This indicates that both the medium composition and the mode of incubation (static or shaking) influenced the laccase isozyme gene expression. This was the first time to report so many laccase isozymes in a fungus. Native PAGE with silver staining showed that laccases were the main protein productions in several media providing a potentially convenient way in purifying laccases from T. gallica.