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Reduction of Toxic Chromium and Partial Localization of Chromium Reductase Activity in Bacterial Isolate DM1 总被引:1,自引:0,他引:1
Summary With advances in biotechnology, bioremediation has become one of the most rapidly developing fields in environmental restoration,
utilizing microorganism to reduce the concentration and toxicity of heavy metals. Hexavalent chromium reducing bacterial culture
(DM1) was isolated from the contaminated sites of chemical industries and its ability to reduce hexavalent chromium to trivalent
chromium, a detoxification process in cell
suspension and cell extract was examined. Based on the biochemical analysis DM1 was identified as Ochrobactrum sp. It could tolerate chromium upto a maximum concentration of 300 ppm, optimum temperature and pH being 35 °C and 7 respectively
for maximum chromium reduction. Assay with the permeabilized cells (treated with toluene and Triton X-100) and cell free extract
demonstrated that the hexavalent chromium reduction is mainly associated with the soluble fraction of the cell. The chromium
reducing activity is inducible. The presence of an induced protein having molecular weight around 30 kDa in the presence of
chromium and absence in cells without chromium points out a possible role of this protein in chromium reduction. The bacterial
isolate DM1 can be exploited for bioremediation of hexavalent chromium containing wastes, since it seems to have the potential
to reduce the toxic hexavalent form of chromium to its nontoxic trivalent form. 相似文献
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Sitali Mushemi-Blake Narbeh Melikian Emma Drasar Amit Bhan Alan Lunt Sujal R. Desai Anne Greenough Mark J. Monaghan Swee Lay Thein Ajay M. Shah 《PloS one》2015,10(8)
Aims
Patients with sickle cell disease have significant morbidity and mortality. Pulmonary hypertension is suggested to be an important contributor but its nature and severity in these patients and how best to non-invasively assess it are controversial. We hypothesised that a high-output state rather than primary pulmonary vascular pathology may be the major abnormality in sickle cell disease. This study aimed to evaluate the characteristics and severity of pulmonary hypertension in patients with sickle cell disease using detailed echocardiography.Methods and Results
We undertook a prospective study in 122 consecutive stable outpatients with sickle cell disease and 30 age, gender and ethnicity-matched healthy controls. Echocardiographic evaluation included 3D ventricular volumes, sphericity, tissue Doppler, and non-invasive estimation of pulmonary vascular resistance. 36% of patients had a tricuspid regurgitant velocity ≥2.5 m.s-1 but only 2% had elevated pulmonary vascular resistance and the prevalence of right ventricular dysfunction was very low. Patients with raised tricuspid regurgitant velocity had significantly elevated biventricular volumes and globular left ventricular remodelling, related primarily to anaemia. In a subgroup of patients who underwent cardiac catheterization, invasive pulmonary haemodynamics confirmed the echocardiographic findings.Conclusions
Elevated cardiac output and left ventricular volume overload secondary to chronic anaemia may be the dominant factor responsible for abnormal cardiopulmonary haemodynamics in patients with sickle cell disease. 3D echocardiography with non-invasive estimation of pulmonary vascular resistance represents a valuable approach for initial evaluation of cardiopulmonary haemodynamics in sickle cell disease. 相似文献6.
The KNaSO4 microphosphor doped with Ce or Ce and Dy prepared by a wet chemical method was studied by scanning electron microscopy (SEM) and characterized by photoluminescence (PL). KNaSO4 has a 5‐µm particle size detected by SEM. The KNaSO4:Ce3+ spectrum shows a single emission band at 327 nm for an excitation of 269 nm due to 5d → 4f transition of the Ce3+ ion, indicating weak spin orbiting coupling of the Ce3+ ground state. Efficient energy transfer takes place from Ce3+ → Dy3+ sublattices indicating that Ce3+ could effectively sensitize Dy3+ (orange emission) and that the Ce3+ emission weakens significantly in KNaSO4. The powder form of prepared KNaSO4 show negligible change in morphologies and hence no effect on the particle size. The characteristics of this powder could provide improved luminescence properties. The development and understanding of this photoluminescence and the effect of Dy3+ on KNaSO4: Ce3+ are discussed. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Urvashi Bhan Amy B. Podsiad Melissa A. Kovach Megan N. Ballinger Venkateshwar Keshamouni Theodore J. Standiford 《PloS one》2015,10(1)
Introduction
Post influenza pneumonia is a leading cause of mortality and morbidity, with mortality rates approaching 60% when bacterial infections are secondary to multi-drug resistant (MDR) pathogens. Staphylococcus aureus, in particular community acquired MRSA (cMRSA), has emerged as a leading cause of post influenza pneumonia.Hypothesis
Linezolid (LZD) prevents acute lung injury in murine model of post influenza bacterial pneumoniaMethods
Mice were infected with HINI strain of influenza and then challenged with cMRSA at day 7, treated with antibiotics (LZD or Vanco) or vehicle 6 hours post bacterial challenge and lungs and bronchoalveolar lavage fluid (BAL) harvested at 24 hours for bacterial clearance, inflammatory cell influx, cytokine/chemokine analysis and assessment of lung injury.Results
Mice treated with LZD or Vanco had lower bacterial burden in the lung and no systemic dissemination, as compared to the control (no antibiotic) group at 24 hours post bacterial challenge. As compared to animals receiving Vanco, LZD group had significantly lower numbers of neutrophils in the BAL (9×103 vs. 2.3×104, p < 0.01), which was associated with reduced levels of chemotactic chemokines and inflammatory cytokines KC, MIP-2, IFN-γ, TNF-α and IL-1β in the BAL. Interestingly, LZD treatment also protected mice from lung injury, as assessed by albumin concentration in the BAL post treatment with H1N1 and cMRSA when compared to vanco treatment. Moreover, treatment with LZD was associated with significantly lower levels of PVL toxin in lungs.Conclusion
Linezolid has unique immunomodulatory effects on host inflammatory response and lung injury in a murine model of post-viral cMRSA pneumonia. 相似文献8.
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Four flavonol glucosides, one new, have been isolated from a methanolic extract of Phlomis spectabilis. Their structures were established as the 3-glucosides and 3-(6″-(E)-p-coumaroyl)glucosides of kaempferol and of kaempferol 7,4′-dimethyl ether. 相似文献
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Kaul M. L. H. Bhan A. K. 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1977,50(5):241-246
Summary Data on chlorophyll mutation frequency after treatment with EMS, DES and gamma-rays and sequential administration of gamma-rays and the two alkylating agents in three varieties of rice have been used to work out quantitatively the effectiveness and efficiency of each mutagen and combination treatment. For effectiveness, the order is EMS > DES and for efficiency it is EMS > DES > gamma-rays. In some sequential treatments (Gamma-rays + DES in IR8 and Basmati; DES + gamma-rays in IR8 and Jhona; Gamma-rays + EMS in IR8 and Basmati; and EMS + gamma-rays in IR8, Jhona and Basmati) mutation frequency is more than additive (synergistic) but these treatments are decisively less efficient because of their relatively high injurious effects in the M1. generation. EMS induces more albinas than gamma-rays do. The mutational spectrum patterns induced by gamma-rays and DES are alike. In general, combination treatments tend to increase the frequency of albinas over other types of chlorophyll mutants. 相似文献