Aims: To isolate an iron‐reducing bacterium and examine its ability of Fe(III) oxide reduction and dechlorination.
Methods and Results: A fermentative facultative anaerobe, strain L17 isolated from subterranean sediment, can reduce Fe(III) oxides and carbon tetrachloride (CT). It was identified as Klebsiella pneumoniae by 16S rRNA sequence analysis. Strain L17 can metabolize fermentable substrates such as citrate, glycerol, glucose and sucrose coupled with the reduction of hydrous ferric oxide, goethite, lepidocrocite and hematite. Fe(III) reduction was influenced by crystal structure of Fe(III) oxide, type of fermentable substrate, metabolic status of the strain, and significantly enhanced by addition of anthraquinone‐2,6‐disulfonate (AQDS). Strain L17 could dechlorinate CT to chloroform, and the rate was accelerated in the presence of Fe(III) oxide and AQDS. Biotic dechlorination by strain L17 and abiotic dechlorination by sorbed Fe(II) were proposed as the two main mechanisms. AQDS might accelerate the dechlorination by transferring electrons from strain L17 to Fe(III) oxide and CT.
Conclusions: K. pneumoniae L17 can reduce Fe(III) oxides and CT. The two reductions can occur simultaneously, and be significantly promoted by AQDS.
Significance and Impact of the Study: This is the first report of a strain of K. pneumoniae capable of reducing Fe(III) oxides and CT. As a strain of environmental origin, strain L17 may have the potential for bioremediation of chlorinated compound‐contaminated sites.
Summary. Molecularly imprinted polymers (MIPs) were synthesized by imprinting a new template-S-(-)-1,1′-binaphthalene-2,2′-diamine (S-DABN) and applied as chiral stationary phases for chiral separation of DABN racemates by high-performance liquid chromatography (HPLC). The influence of some key factors on the chiral recognition ability of MIPs, such as the type of functional monomers and porogen and the molar ratio of template to monomer, was systematically investigated. The chromatographic conditions, such as mobile phase composition, sample loading, and flow rate, were also measured. The chiral separation for DABN racemates under the optimum chromatographic conditions by using MIP chiral stationary phase (CSP) of P3, prepared with the S-DABN/MAA ratio = 1/4 and used acetonitrile (2 mL) and chloroform (4 mL) as porogen, showed the highest separation factor (2.14). Frontal analysis was used to evaluate affinity to the target molecule of MIPs. The binding sites (B t ) of MIPs and dissociation constant (K d ) were estimated as 4.56 μmol g −1 and 1.40 mmol L −1 , respectively. In comparison with the previous studies, this approach had the advantages, such as the higher separation factor, easy preparation, and cost-effectiveness, it not only has the value for research but also has a potential in industrial application.
Several polyethers containing pendent 3,6-diarylcarbazolyl moieties have been synthesized by the multi-step synthetic routes. Full characterization of their structures is presented. The polymers represent materials of high thermal stability with initial thermal degradation temperatures exceeding 419°C. The glass transition temperatures of the amorphous materials were in the range of 66-108°C. The electron photoemission spectra of thin layers of the polymers showed ionization potentials in the range of 5.47-5.69 eV. Hole transporting properties of the polymeric materials were tested in the structures of organic light emitting diodes with Alq 3 as the green emitter. The device containing hole transporting layers of the polymer with 3,6-di(4-biphenyl)carbazolyl moieties exhibited the best overall performance with a maximum photometric efficiency of about 2.3 cd/A and maximum brightness exceeding 2630 cd/m 2 .
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