PsrA is not regulated by the GacS/GacA two-component system in <i>P. fluorescens</i> 2P24.

<p>Transcriptional fusion assay (A) and Western blot analysis (B) demonstrating that the expression of PsrA is not altered in the <i>gacA</i> mutant or in the <i>gacS</i> mutant.</p

Transcription of small non-coding RNA genes <i>rsmX</i> (A), <i>rsmY</i> (B), and <i>rsmZ</i> (C) and their cognate regulator genes <i>rsmE</i> (D) and <i>rsmA</i> (E) in <i>P. fluorescen</i>s 2P24, its <i>psrA</i> mutant and its <i>gacA</i> mutants.

<p>(F) HPLC analysis of 2,4-DAPG production by strain 2P24 and its <i>rsmA</i> mutant. All experiments were performed in triplicate, and the mean values ±SD are indicated. Growth is indicated by the dotted line.</p

The transcriptional fusions <i>psrA</i>-<i>lacZ</i> and <i>phlF</i>-<i>lacZ</i> were introduced into <i>P. fluorescens</i> 2P24, respectively.

<p>Bacteria were grown in LB medium, and absorbance was measured at 600 nm (solid circles, <i>psrA</i>-<i>lacZ</i>; open circles, <i>phlF</i>-<i>lacZ</i>). Expression of the fusions was assessed by measuring levels of β-galactosidase. Black shading represents <i>psrA</i>-<i>lacZ</i> expression, and grey shading represents <i>phlF</i>-<i>lacZ</i> expression. Triplicate cultures were assayed and the standard deviations are presented with error bars.</p

Schematic of the physical location of the <i>psrA</i> gene in <i>Pseudomonas fluorescens</i> 2P24.

<p><i>lexA</i>, gene encoding LexA repressor protein; <i>psrA</i>, <i>Pseudomonas</i> sigma regulator; <i>nagZ</i>, gene encoding β-<i>N</i>-acetyl-_D-glucosaminidase; other gene names refer to the gene symbols as annotated in the <i>Pseudomonas fluorescens</i> Pf0-1 genome (GenBank accession no. CP000094). The bars indicate the fragments cloned into the vector pHSG299 to obtain p299DpsrA. The fragment inserted into pRK415 was used to complement the <i>psrA</i> mutant. Two putative PsrA binding sites are indicated with inverted arrows. Δ, the region deleted in the mutant PM113 and in plasmid p229DpsrA. Artificial restriction sites are marked with asterisks.</p

Adsorption of 2,4,6-trichlorophenol by magnetic mesoporous SiO₂ and the adsorption capacity regeneration by UV photolysis

<p>The adsorption of 2,4,6-trichlorophenol (2,4,6-TCP) on synthesized magnetic mesoporous silica (Fe₃O₄/SiO₂/m-SiO₂, MMS) composites and the regeneration of its adsorption capacity through direct UV photolysis was performed in this work. MMS exhibited good performance in removing 2,4,6-TCP from aqueous solutions. The adsorption ratio of 2,4,6-TCP was determined to be influenced by aquatic pH, dissolved humic acids, ionic strength, temperature, and the loaded adsorbents. The adsorption isotherm fit the Freundlich and Polanyi–Manes model better than the Langmuir model, which indicated that the adsorption of 2,4,6-TCP was more likely a pore-filling process. The calculated adsorbed capacity for 2,4,6-TCP on MMS was 55 mg/g. Direct UV photolysis could decompose the adsorbed 2,4,6-TCP and later regenerate the adsorption capacity of MMS to a certain degree; however, the outer mesoporous silica layer was not UV-persistent, and large parts of the mesoporous silica layer were also shown to be corrupted from the Fe₃O₄/SiO₂ core. Therefore, after long duration UV irradiation, the adsorption of 2,4,6-TCP on regenerated MMS was much lower than on freshly synthesized MMS. These results suggest that the photostability of magnetic core-shell-like nanocomposites should be investigated because parts of the composites might leach into the bulk phase during practical use and cause potential environmental risks, similar to other well-known nanomaterials.</p

RpoS regulates the 2,4-DAPG production via RsmA in <i>P. fluorescens</i> 2P24.

<p>Biosynthesis of 2,4-DAPG in strains 2P24 and its <i>rpoS</i> mutant was assayed by HPLC (A). The expression of the <i>rpoS</i> gene is activated by PsrA in strain 2P24 (B). Expression of the <i>rsmA</i> gene in the wild type strain 2P24 and the <i>rpoS</i> mutant PM303 (C). Binding assay of PsrA to the <i>rpoS</i> promoter. 30 ng DNA probe was incubated with increasing amounts of PsrA. Lane 1, DNA probe alone; lanes 2–5, DNA probe incubated with 25, 50, 75, or 100 ng PsrA, respectively; lane 6, the mutated DNA probe from p399rpoSp derivative (a 3-bp substitution [GGG for TTT] in the <i>rpoS</i> promoter) incubated with 100 ng PsrA (D). Western blot analysis of RsmA-V in strain 2P24 and the <i>rpoS</i> mutant (E).</p

EMSA of PsrA with the <i>phlA</i> (30 ng) promoter fragment that contains PsrA-binding sequence showing formation of a PsrA-DNA complex.

<p>Lane 1, DNA probe alone; lanes 2–5, DNA probe incubated with 50, 75, 100, or 150 ng PsrA, respectively; lane 6, the mutagenized DNA probe from p399phlAp derivative (a 3-bp substitution [GGG for TTT] in the <i>phlA</i> promoter) incubated with 150 ng PsrA (A). Biosynthesis of 2,4-DAPG in strain 2P24 and its <i>psrA</i> and <i>phlF</i> mutants was assayed by HPLC (B). For transcriptional assay, strain 2P24 and its <i>psrA</i> mutant carrying p970Gm-phlAp (wild type <i>phlA</i>-<i>lacZ</i>), p970Gm-phlApM3G (PsrA box mutTTT <i>phlA</i>-<i>lacZ</i>) or p970Gm-phlAD3T (PsrA box ΔTTT <i>phlA</i>-<i>lacZ</i>) were grown in LB, and β-galactosidase activities were determined (C). Analysis of PhlA-V levels in strain 2P24 and the <i>psrA</i> mutant by immunoblotting. An antibody directed against 3-phosphoglycerate kinase α (α-PGK) is used as a loading control in this and later blots (D). All experiments were performed in triplicate, and the mean values ±SD are indicated. Growth is indicated by the dotted line.</p

Presentation_1.PDF

<p>This study implements temporal and spatial appraisals on the operational performance and corresponding microbial community structure of a full-scale advanced anaerobic expanded granular sludge bed (AnaEG) which was used to treat low organic loading starch processing wastewater. Results showed stable treatment efficiency could be maintained with long-term erratic influent quality, and a major reaction zone located at the bottom of the AnaEG, where the main pollutant removal rate was greater than 90%. Remarkably, high-throughput sequencing of 16S rRNA gene amplicons displayed that the predominant members constructed the major part of the overall microbial community and showed highly temporal stability. They were affiliated to Chloroflexi (16.4%), Proteobacteria (14.01%), Firmicutes (8.76%), Bacteroidetes (7.85%), Cloacimonetes (3.21%), Ignavibacteriae (1.80%), Synergistetes (1.11%), Thermotogae (0.98%), and Euryarchaeota (3.18%). This part of microorganism implemented the long-term stable treatment efficiency of the reactor. Simultaneously, an extraordinary spatial homogeneity in the granule physic properties and microbial community structure along the vertical direction was observed within the AnaEG. In conclusion, the microbial community structure and the bioreactor’s performance showed notable spatial and temporal consistency, and the predominant populations guaranteed a long-term favorable treatment performance of the AnaEG. It provides us with a better understanding of the mechanism of this recently proposed anaerobic reactor which was used in low organic loading wastewater treatment.</p

Characterization of monoclonal antibody 1F5 by immunofluorescence assay.

<p>Monoclonal antibody 1F5 was used to perform indirect immunofluorescence assay on DF-1 cells infected with DTMUV FX2010 and 293T cells transfected with pCAGGS-E plasmids. A) DF-1 cells infected with DTMUV FX2010, B) control DF-1 cells, C) 293T cells transfected with recombinant plasmid pCAGGS-E, and D) control 293T cells fixed with 4% paraformaldehyde, and then incubated with mAb 1F5 and FITC-conjugated goat anti-mouse IgG, in turn. Cells were mounted with 10 mM p-phenylenediamine (PPD) in glycerol-PBS and observed under a fluorescent microscope.</p

Comparison of percent inhibition obtained in blocking ELISA and SNT using a serially diluted duck anti-DTMUV serum.

<p>Note: “+” positive and “−” negative.</p