Microbial aspects of acid generation and bioremediation with relevance to indian mining

The role of Acidithiobacillus group of bacteria in acid generation and heavy metal dissolution was studied with relevance to some Indian mines. Microorganisms implicated in acid generation such as Acidithiobacillus Acidithicibacillus thiooxidans and Leptospirillum ferrooxidans were isolated from abandoned mines, waste rocks and tailing dumps. Arsenite oxidizing Thiomonas and Bacillus group of bacteria were isolated and their ability to oxidize As (111) to As (V) established. Mine isolated Sulfate reducing bacteria were used to remove dissolved copper, zinc, iron and arsenic from solutions.

Photocytotoxic Oxovanadium(IV) Complexes Showing Light-Induced DNA and Protein Cleavage Activity

Oxovanadium(IV) complexes [VO(L)(B)]Cl-2 (1-3), where L is bis(2-benzimidazolylmethyl)amine and B is 1,10-phenanthroline(phen),dipyrido[3,2-d:2',3'-f]quinoxaline(dpq) or dipyrido[3,2-a:2',3'-c]phenazine (dppz), have been prepared, characterized, and their photo-induced DNA and protein cleavage activity studied. The photocytotoxicity of complex 3 has been studied using adenocarcinoma A549 cells, The phen complex 1, structurally characterized by single-crystal X-ray crystallography, shows the presence of a vanadyl group in six-coordinate VON5 coordination geometry. The ligands L and phen display tridentate and bidentate N-donor chelating binding modes, respectively. The complexes exhibit a d-d band near 740 nm in 15% DMF-Tris-HCl buffer (pH 7.2). The phen and dpq complexes display an irreversible cathodic cyclic voltammetric response near -0.8 V in 20% DMF-Tris-HCl buffer having 0.1 M KCl as supporting electrolyte. The dppz complex 3 exhibits a quasi-reversible voltammogram near -0.6 V (vs SCE) that is assignable to the V(IV)-V(III)couple. The complexes bind to calf thymus DNA giving binding constant values in the range of 6.6 x 10(4)-2.9 x 10(5) M-1. The binding site size, thermal melting and viscosity binding data suggest DNA surface and/or groove binding nature of the complexes. The complexes show poor ``chemical nuclease'' activity in dark in the presence of 3-mercaptopropionic acid or hydrogen peroxide. The dpq and dppz complexes are efficient photocleavers of plasmid DNA in UV-A light of 365 nm via a mechanistic pathway that involves formation of both singlet oxygen and hydroxyl radicals. The complexes show significant photocleavage of DNA in near-IR light (>750 nm) via hydroxyl radical pathway. Among the three complexes, the dppz complex 3 shows significant BSA and lysozyme protein cleavage activity in UV-A light of 365 nm via hydroxyl radical pathway. The dppz complex 3 also exhibits photocytotoxicity in non-small cell lung carcinoma/human lung adenocarcinoma A549 cells giving IC50 value of 17 mu M in visible light(IC50 = 175 mu M in dark).

Expression, purification and X-ray analysis of 1,3-propanediol dehydrogenase (Aq_1145) from Aquifex aeolicus VF5

1,3-Propanediol dehydrogenase is an enzyme that catalyzes the oxidation of 1,3-propanediol to 3-hydroxypropanal with the simultaneous reduction of NADP(+) to NADPH. SeMet-labelled 1,3-propanediol dehydrogenase protein from the hyperthermophilic bacterium Aquifex aeolicus VF5 was overexpressed in Escherichia coli and purified to homogeneity. Crystals of this protein were grown from an acidic buffer with ammonium sulfate as the precipitant. Single-wavelength data were collected at the selenium peak to a resolution of 2.4 angstrom. The crystal belonged to space group P3(2), with unit-cell parameters a = b = 142.19, c = 123.34 angstrom. The structure contained two dimers in the asymmetric unit and was solved by the MR-SAD approach.

Novel synthesis of superparamagnetic Ni-Co-B nanoparticles and their effect on superconductor properties of MgB2

A new procedure for the preparation of amorphous Ni-Co-B nanoparticles is reported, with a detailed investigation of their morphology by X-ray diffraction and transmission electron microscopy, as well as their magnetic properties. Many factors, such as chemical composition, anisotropy, size and shape of the particles, were controlled through chemical synthesis, resulting in the control of morphological and magnetic properties of the nanoparticles. Controlling pH values with ethylenediamine and using sodium dodecyl sulfate surfactant lowered the size of the nanoparticles to below 10 nm. Such a small structure and chemical disorder in nanocrystalline materials lead to magnetic properties that are different from those in their bulk-sized counterparts. The obtained nanoparticles can be used for different purposes, from pharmaceutical applications to implementations in different materials technology. The focus of this research is the synthesis of Ni-Co-B nanoparticles in a new way and studying the reaction of Ni-Co-B nanoparticles with Mg and B precursors and their effect on MgB2 properties. New nanostructures are formed in the reaction of Ni-Co-B nanoparticles with Mg: Mg2Ni, Co2Mg and possibly Mg2Co.

Oxovanadium(IV) complexes of phenanthroline bases: the dipyridophenazine complex as a near-IR photocytotoxic agent

Oxovanadium(IV) complexes [VOCl(B)(2)]Cl (1-3) of phenanthroline bases (B), viz. 1,10-phenanthroline (phen in 1), dipyrido[3,2-d: 2', 3'-f] quinoxaline (dpq in 2) and dipyrido[3,2-a: 2', 3'-c] phenazine (dppz in 3), have been prepared, characterized and their DNA and protein binding, photo-induced DNA and protein cleavage activity andm photocytotoxicity have been studied. Complex 2, structurally characterized by X-ray crystallography, shows the presence of a vanadyl group in VOClN4 coordination geometry. The dpq ligand displays a chelating mode of binding with a N-donor site trans to the oxo-group. The chloride ligand is cis to the oxo-group. The one-electron paramagnetic complexes show a d-d band near 715 nm in 15% DMF-Tris-HCl buffer. The complexes are redox active exhibiting a V(IV)/V(III) redox couple within -0.5 to -0.7 V vs. SCE in 20% DMF-Tris-HCl/0.1 M KCl. The complexes bind to calf thymus (CT) DNA in the order: 3 (dppz) > 2 (dpq) > 1 (phen). The binding data reveal the groove and/or partial intercalative DNA binding nature of the complexes. The complexes show chemical nuclease'' activity in the dark in the presence of 3-mercaptopropionic acid or hydrogen peroxide via a hydroxyl radical pathway. The dpq and dppz complexes are efficient photocleavers of DNA in UV-A light of 365 nm forming reactive singlet oxygen (O-1(2)) and hydroxyl radical ((OH)-O-center dot) species. Complexes 2 and 3 also show DNA cleavage activity in red light (> 750 nm) by an exclusive (OH)-O-center dot pathway. The complexes display a binding propensity to bovine serum albumin (BSA) protein giving K-BSA values in the range of 7.1 x 10(4)-1.8 x 10(5) M-1. The dppz complex 3 shows BSA and lysozyme protein cleavage activity in UV-A light of 365 nm via (OH)-O-center dot pathway. The dppz complex 3 exhibits significant PDT effect in human cervical cancer HeLa cells giving IC50 values of 1.0 mu M and 12.0 mu M in UV-A and visible light, respectively (IC50 = > 100 mu M in the dark).

Delamination of Surfactant-Intercalated Brucite-Like Hydroxy Salts of Cobalt and Copper and Solvothermal Decomposition of the Resultant Colloidal Dispersions

Surfactant anion intercalated hydroxy salts of copper and cobalt of the formula M(OH)(2-x)(surf)(x)center dot mH(2)O [M = Cu, Co; surf = dodecyl sulfate. dodecyl benzene sulfonate. and x = 0.5 for Cu and 0.67 for Co] delaminate readily in 1-butanol to give translucent colloidal dispersions that are stable for months. The extent of delamination and the colloidal dispersion observed in these solids is higher than what had been observed for layered double hydroxides. The dispersions yield the corresponding nanoparticulate oxides on solvothermal decomposition. While the copper hydroxy salt forms similar to 300 nm dendrimer-like CuO nanostructures comprising nanorods of similar to 10 nm diameter, the cobalt analogue forms similar to 20 nm superparamagnetic particles of Co3O4.

Coordination polymers and hybrid networks of different dimensionalities formed by metal sulfites

In our effort to explore the use of the sulfite ion to design hybrid and open-framework materials, we have been able to prepare, under hydrothermal conditions, zero-dimensional [Zn(C12H8N2)(SO3)]center dot 2H(2)O, I (a = 7.5737(5) angstrom, b = 10.3969(6) angstrom, c = 10.3986(6) angstrom, alpha = 64.172(1)degrees, beta = 69.395(1)degrees, gamma = 79.333(1)degrees, Z = 2, and space group P (1) over bar), one-dimensional [Zn-2(C12H8N2)(SO3)(2)(H2O)], II (a = 8.0247(3) angstrom, b = 9.4962(3) angstrom, c = 10.2740(2) A, alpha = 81.070(1)degrees, beta = 80.438(1)degrees, gamma = 75.66(5)degrees, Z = 2, and space group P (1) over bar), two-dimensional [Zn-2(C10H8N2)(SO3)(2)]center dot H2O, III (a = 16.6062(1) angstrom, b = 4.7935(1) angstrom, c = 19.2721(5) angstrom, beta = 100.674(2)degrees, Z = 4, and space group C2/c), and three-dimensional [Zn-4(C6H12N2)(SO3)(4)(H2O)(4)], IV (a = 11.0793(3) angstrom, c = 8.8246(3) angstrom, Z = 2, and space group P42nm), of which the last three are coordination polymers. A hybrid open-framework sulfite-sulfate of the composition [C2H10N2][Nd(SO3)(SO4)(H2O)](2), V (a = 9.0880(3) angstrom, b = 6.9429(2) angstrom, c = 13.0805(5) A, beta = 91.551(2)degrees, Z = 2, and space group P2(1)/c), with a layered structure containing metal-oxygen-metal bonds has also been described.

Investigation of dye functional group on the photocatalytic degradation of dyes by nano-TiO2

The photocatalytic degradation of five anionic, eight cationic and three solvent dyes using combustion-synthesized nano-TiO2 (CSTiO2) and commercial Degussa P-25 TiO2 (DP-25) were evaluated to determine the effect of the functional group in the dye. The degradation of the dyes was quantified using the initial rate of decolorization and mineralization. The decolorization of the anionic dyes with CSTiO2 followed the order: indigo carmine > eosin Y > amido black 10B > alizarin cyanine green > orange G. The decolorization of the cationic dyes with DP-25 followed the order: malachite green > pyronin Y > rhodamine 6G > azure B > nile blue sulfate > auramine O approximate to acriflavine P approximate to safranin O. CSTiO2 showed higher rates of decolorization and mineralization for all the anionic dyes compared to DP-25, while DP-25 was better in terms of decolorization for most of the cationic dyes. The solvent dyes exhibited adsorption dependent decolorization. The order of decolorization and mineralization of the anionic and cationic dyes (a) with CS TiO2 and DP-25 was different and correlated with the surface properties of these catalysts (b) were rationalized with the molecular structure of the dye and the degradation pathway of the dye. (C) 2009 Elsevier B.V. All rights reserved.

Inhibition of a Protein Tyrosine Phosphatase Using Mesoporous Oxides

The feasibility of utilizing mesoporous matrices of alumina and silica for the inhibition of enzymatic activity is presented here. These studies were performed on a protein tyrosine phosphatase by the name chick retinal tyrosine phosphotase-2 (CRYP-2), a protein that is identical in sequence to the human glomerular epithelial protein-1 and involved in hepatic carcinoma. The inhibition of CRYP-2 is of tremendous therapeutic importance. Inhibition of catalytic activity was examined using the Sustained delivery of p-nitrocatechol sulfate (pNCS) from bare and amine functionalized mesoporous silica (MCM-48) and mesoporous alumina (Al2O3). Among the various mesoporous matrices employed, amine functionalized MCM-48 exhibited the best release of pNCS and also inhibition of CRYP-2. The maximum speed of reaction nu(max) (= 160 +/- 10 mu mol/mnt/mg) and inhibition constant K-i (=85.0 +/- 5.0 mu mol) estimated using a competitive inhibition model were Found to be very similar to inhibition activities of protein tyrosine phosphatases using other methods.

Synthesis of BaSO4 nanoparticles by precipitation method using sodium hexa metaphosphate as a stabilizer

We describe the synthesis and structure of Barium sulfate nanoparticles by precipitation method in the presence of water soluble inorganic stabilizing agent, sodium hexametaphosphate, (NaPO3)(6). The structural parameters were refined by the Rietveld refinement method using powder X-ray diffraction data. Barium sulfate nanoparticles were crystallized in the orthorhombic structure with space group Pbnm (No. 62) having the lattice parameters a = 7.215(1) (angstrom), b = 8.949(1) (angstrom) and c = 5.501 (1) (angstrom) respectively. Transmission electron microscopy study reveals that the nanoparticles are size range, 30-50 nm. Fourier transform infrared spectra showed distinct absorption due to the SO42- moiety at 1115 and 1084 cm(-1) indicating formation of barium sulfate nanoparticles free from the phosphate group from the stabilizer used in the synthesis. (C) 2009 Elsevier Ltd. All rights reserved.

Soy supplementation and role of equol production capability in postmenopausal women using tibolone: effects on cardiovascular risk markers

Tibolone, a synthetic steroid, is effective in the treatment of postmenopausal symptoms. Its cardiovascular safety profile has been questioned, because tibolone reduces the levels of high-density lipoprotein (HDL) cholesterol. Soy-derived isoflavones may offer health benefits, particularly as regards lipids and also other cardiovascular disease (CVD) risk factors. The soy-isoflavone metabolite equol is thought to be the key as regards soy-related beneficial effects. We studied the effects of soy supplementation on various CVD risk factors in postmenopausal monkeys and postmenopausal women using tibolone. In addition, the impact of equol production capability was studied. A total of 18 monkeys received casein/lactalbumin (C/L) (placebo), tibolone, soy (a woman s equivalent dose of 138 mg of isoflavones), or soy with tibolone in a randomized order for 14 weeks periods, and there was a 4-week washout (C/L) in between treatments. Postmenopausal women using tibolone (N=110) were screened by means of a one-week soy challenge to find 20 women with equol production capability (4-fold elevation from baseline equol level) and 20 control women, and treated in a randomized cross-over trial with a soy powder (52 g of soy protein containing 112 mg of isoflavones) or placebo for 8 weeks. Before and after the treatments lipids and lipoproteins were assessed in both monkeys and women. In addition, blood pressure, arterial stiffness, endothelial function, sex steroids, sex hormone-binding globulin (SHBG), and vascular inflammation markers were assessed. A 14% increase in plasma low-density lipoprotein (LDL) + very low-density lipoprotein (VLDL) cholesterol was observed in tibolone-treated monkeys vs. placebo. Soy treatment resulted in a 18% decrease in LDL+VLDL cholesterol, and concomitant supplementation with tibolone did not negate the LDL+VLDL cholesterol-lowering effect of soy. A 30% increase in HDL cholesterol was observed in monkeys fed with soy, whereas HDL cholesterol levels were reduced (48%) after tibolone. Interestingly, Soy+Tibolone diet conserved HDL cholesterol levels. Tibolone alone increased the total cholesterol (TC):HDL cholesterol ratio, whereas it was reduced by Soy or Soy+Tibolone. In postmenopausal women using tibolone, reductions in the levels of total cholesterol and LDL cholesterol were seen after soy supplementation compared with placebo, but there was no effect on HDL cholesterol, blood pressure, arterial stiffness or endothelial function. Soy supplementation decreased the levels of estrone in equol producers, and those of testosterone in the entire study population. No changes were seen in the levels of androstenedione, dehydroepiandrosterone sulfate, or SHBG. The levels of vascular cell adhesion molecule-1 increased, and platelet-selectin decreased after soy treatment, whereas C-reactive protein and intercellular adhesion molecule-1 remained unchanged. At baseline and unrelated to soy treatment, equol producers had lower systolic, diastolic and mean arterial pressures, less arterial stiffness and better endothelial function than non-producers. To conclude, soy supplementation reversed the tibolone-induced fall in HDL cholesterol in postmenopausal monkeys, but this effect was not seen in women taking tibolone. Equol production capability was associated with beneficial cardiovascular changes and thus, this characteristic may offer cardiovascular benefits, at least in women using tibolone.

The ambient aerosol characterization during the prescribed bushfire season in Brisbane 2013

Prescribed burnings are conducted in Queensland each year from August until November aiming to decrease the impact of bushfire hazards and maintain the health of vegetation. This study reports chemical characteristics of the ambient aerosol, with a focus on source apportionment of the organic aerosol (OA)fraction, during the prescribed biomass burning (BB) season in Brisbane 2013. All measurements were conducted within the International Laboratory for Air Quality and Health (ILAQH) located in Brisbane’s Central Business District. Chemical composition, degree of ageing and the influence of BB emission on the air quality of central Brisbane were characterized using a compact Time of Flight Aerosol Mass Spectrometer (cToF-AMS). AMS loadings were dominated by OA (64 %), followed by, sulfate (17 %), ammonium (14 %) and nitrates (5 %). Source apportionment was applied on the AMS OA mass spectra via the multilinear engine solver (ME-2) implementation within the recently developed Source Finder (SoFi) interface. Six factors were extracted including hydrocarbon-like OA (HOA), cooking-related OA (COA), biomass burning OA (BBOA), low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), and nitrogen-enriched OA (NOA). The aerosol fraction that was attributed to BB factor was 9 %, on average over the sampling period. The high proportion of oxygenated OA (72 %), typically representing aged emissions, could possess a fraction of oxygenated species transformed from BB components on their way to the sampling site.

Synthesis and characterization of nano-MnO2 for electrochemical supercapacitor studies

Nanostructured MnO2 was synthesized at ambient condition by reduction of potassium permanganate with aniline. Powder X-ray diffraction, thermal analysis (thermogravimetric and differential thermal analysis), Brunauer-Emmett-Teller surface area, and infrared spectroscopy studies were carried out for physical and chemical characterization. The as-prepared MnO2 was amorphous and contained particles of 5-10 nm diameter. Upon annealing at temperatures >400°C, the amorphous MnO2 attained crystalline α-phase with a concomitant change in morphology. A gradual conversion of nanoparticles to nanorods is evident from scanning electron microscopy and transmission electron microscopy (TEM) studies. High-resolution TEM images suggested that nanoparticles and nanorods grow in different crystallographic planes. Capacitance behavior was studied by cyclic voltammetry and galvanostatic charge-discharge cycling in a potential range from -0.2 to 1.0 V vs SCE in 0.1 M sodium sulfate solution. Specific capacitance of about 250 F g-1 was obtained at a current density of 0.5 mA cm-2(0.8 A g-1).

Detection of alpha(2u)-globulin and its bound putative pheromones in the preputial gland of the Indian commensal rat (Rattus rattus) using mass spectrometry

The role of pheromones and pheromone-binding proteins in the laboratory rat has been extensively investigated. However, we have previously reported that the preputial gland of the Indian commensal rat produces a variety of pheromonal molecules and preputial glands would seem to be the predominant source for pheromonal communication. The presence of pheromone-binding proteins has not yet been identified in the preputial gland of the Indian commensal rat; therefore, the experiments were designed to unravel the alpha(2u)-globulin (alpha 2u) and its bound volatiles in the commensal rat. Total preputial glandular proteins were first fractionated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) and subsequently analyzed by mass spectrometry. Further, we purified alpha 2u and screened for the presence of bound pheromonal molecules with the aid of gas chromatography/mass spectrometry (GC/MS). A novel alpha 2u was identified with a high score and this protein has not been previously described as present in the preputial gland of Indian commensal rats.This novel alpha 2u was then characterized by tandem mass spectrometry (MS/MS). Peptides with m/z values of 969, 1192, 1303 and 1876 were further fragmented with the aid of MS/MS and generated de novo sequences which provided additional evidence for the presence of alpha 2u in the preputial gland. Finally, we identified the presence of farnesol 1 and 2 bound to alpha 2u. The present investigation confirms the presence of alpha 2u (18.54 kDa) in the preputial gland of the Indian commensal rat and identifies farnesol 1 and 2 as probably involved in chemo-communication by the Indian commensal rat.Copyright (C) 2010 John Wiley & Sons, Ltd.

Biosynthesis of sulfated mucopolysaccharides in relation to vitamins A and K

1.(1) Incorporation of Na235SO4 into acid mucopolysaccharides of intestine and colon tissue has been studied in normal, vitamin A-deficient and excess vitamin A-fed rats. 2. (2) Vitamin A deficiency resulted in a significant decrease in [35S]sulfate incorporation into mucopolysaccharides isolated from intestines of male rats. There was no significant change in the total mucopolysaccharides per gram of fresh tissue. 3. (3) When rats are fed excessive amounts of retinyl acetate, increased [35S]sulfate incorporation into mucopolysaccharides of rat intestine and colon is observed. 4. (4) Supplementation of vitamin K1 to rats fed excessive amounts of vitamin A restores the incorporation of [35S]sulfate into the acid mucopolysaccharides to the normal level. 5. (5) The implications of these findings with special reference to the role of vitamins A and K in the synthesis of sulfated mucopolysaccharides are discussed.