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1.
Fluorescent and incandescent lighting systems were applied for batch photofermentative hydrogen production by four purple non-sulfur photosynthetic bacteria (PNSB). The hydrogen production efficiency of Rhodopseudomonas palustris, Rhodobacter sphaeroides, Rhodobacter capsulatus, and Rhodospirillum rubrum was evaluated using different carbon sources (acetate, butyrate, lactate, and malate). Incandescent light was found to be more effective for bacteria cell growth and hydrogen production. It was observed that PNSB followed substrate selection criteria for hydrogen production. Only R. palustris was able to produce hydrogen using most carbon sources. Cell density was almost constant, but cell growth rate and hydrogen production were significantly varied under the different lighting systems. The kinetics study suggested that initial substrate concentration had a positive correlation with lag phase duration. Among the PNSB, R. palustris grew faster and had higher hydrogen yields of 1.58, 4.92, and 2.57 mol H2/mol using acetate, butyrate, and lactate, respectively. In the integrative approach with dark fermentation effluents rich in organic acids, R. palustris should be enriched in the phototrophic microbial consortium of the continuous hydrogen production system.  相似文献   

2.
Ozonation experiments were performed with model wastewater containing 100 g m?3 benzothiazole concentration. Ozonation was carried out in jet-loop reactor with external recirculation of the reaction mixture. Benzothiazole removal efficiency was 87%. Benzothiazole residual concentration and concentration of its degradation products after ozonation were expressed as COD and TOC values. In terms of biodegradability, respirometric measurements with activated sludge microorganisms were performed on samples of ozonated model wastewater. Increase in oxygen uptake rate compared to the endogenous phase was recorded in all measurements. Experimental data were fitted by Monod and Haldane equations. The best match of experimental and calculated data was achieved by Haldane kinetic model due to substrate and degradation products inhibition. The results of respirometric measurements indicate that ozonation improves the biodegradability of model wastewater and increases the oxygen uptake rate of activated sludge. However, substrate inhibition was observed with higher COD content. Toxicity test was performed on three organisms (Sinapis alba, Daphnia magna and Vibrio fischeri), and has shown that each studied organism responds differently on ozonated wastewater. Inhibition of S. alba decreases with ozonation time. Inhibition of V. fischeri reached maximum at 10 min of ozonation and inhibition of D. magna has minimum at the same ozonation time.  相似文献   

3.
Weissella cibaria RBA12 produced a maximum of 9 mg/ml dextran (with 90% efficiency) using shake flask culture under the optimized concentration of medium components viz. 2% (w/v) of each sucrose, yeast extract, and K2HPO4 after incubation at optimized conditions of 20 °C and 180 rpm for 24 h. The optimized medium and conditions were used for scale-up of dextran production from Weissella cibaria RBA12 in 2.5-l working volume under batch fermentation in a bioreactor that yielded a maximum of 9.3 mg/ml dextran (with 93% efficiency) at 14 h. After 14 h, dextran produced was utilized by the bacterium till 18 h in its stationary phase under sucrose depleted conditions. Dextran utilization was further studied by fed-batch fermentation using sucrose feed. Dextran on production under fed-batch fermentation in bioreactor gave 35.8 mg/ml after 32 h. In fed-batch mode, there was no decrease in dextran concentration as observed in the batch mode. This showed that the utilization of dextran by Weissella cibaria RBA12 is initiated when there is sucrose depletion and therefore the presence of sucrose can possibly overcome the dextran hydrolysis. This is the first report of utilization of dextran, post-sucrose depletion by Weissella sp. studied in bioreactor.  相似文献   

4.
The aim of our study was to investigate the potential association of mRNA expression and plasma levels of the LIM domain 7 (LMO7) gene with the pathogenesis of dilated cardiomyopathy (DCM). Two SNPs of the LMO7 gene were genotyped in 310 patients with DCM and 415 controls. Our results showed that SNP rs7986131 (p = 0.002, OR = 1.38, 95% CI = 1.12–1.71), but not SNP rs4884021, was associated with DCM in the Han Chinese population. Haplotype analysis showed that the haplotype GT was associated with increased DCM susceptibility while AC was a protective haplotype. The Cox multivariate survival analysis indicated that the rs7986131 TT genotype (HR 1.659, 95% CI = 1.122–2.454, p = 0.011) was an independent multivariate predictor for shorter overall survival in patients with DCM. LMO7 mRNA expression and plasma LMO7 levels were significantly decreased in DCM (p < 0.0001). Spearman correlation test revealed that the plasma LMO7 level was negatively associated with left ventricular end-diastolic diameter (r = ?0.384, p = 0.01), left ventricular end-diastolic volume (r = ?0.375, p = 0.012), and brain natriuretic peptide (r = ?0.482, p = 0.001). Our study suggested that the LMO7 gene may play an important role in the pathogenesis of DCM in the Han Chinese population.  相似文献   

5.
Co-doped BiVO4, a visible-light-responsive photocatalytic semiconductor, was synthesized using a microwave hydrothermal method. The doped sample exhibited much higher photocatalytic activity for malachite green degradation under visible light irradiation than undoped BiVO4. Similarly, improved inactivation efficiency toward Escherichia coli and Chlamydomonas pulsatilla (green tide) were observed with Co-doped BiVO4. The degradation of malachite green by Co-doped BiVO4 reaches 99% within 90 min irradiation to visible light. Similarly, the inactivation of Escherichia coli reaches 81.3% in 5 h and Chlamydomonas pulsatilla reaches 65.6% in 1 h irradiation to visible light. The enhanced photoactivity is believed to be due to the increment of the visible light absorption range by narrowing the band gap energy. In addition, the highly exposed reactive (010) facets can efficiently capture the photoinduced electrons, promote charge separation, and reduce recombination probability. Thus, these findings provide mechanistic insight into the effectiveness of Co-doped BiVO4 semiconductors for the treatment of wastewater that contains industrial effluents and microorganisms.  相似文献   

6.
In this study, five of popularly used medicinal plants as Cichorium intybus, Anethum graveolens seed, Thymus vulgaris, Fumaria officinalis and Hibiscus sabdariffa Syn: Hibiscus gossypifolius were prepared from Herbal Pharmacies in Tehran. The amounts of Al, Br, Ca, Cl, Cr, Fe, K, Mg, Mn, Na, V and Zn in samples were determined using instrumental neutron activation analysis. In this method, Tehran research reactor as a neutron source and relative INAA have been used as the analysis procedure. Highest levels of Cr (5 mg/kg), Ca (28316 mg/kg) and Mg (4134 mg/kg) were detected in Thymus vulgaris and F1umaria officinalis, respectively.  相似文献   

7.
Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.  相似文献   

8.
This study investigated use of leaf, seed, seed shell and pod extracts of Cola nitida for the green synthesis of silver-alloy nanoparticles (Ag–AuNPs). The Ag–AuNPs formed were dark brown with maxima absorbance in the range of 497–531 nm. FTIR peaks at 3290–3396 and 1635–1647 cm?1 showed that proteins were the capping and stabilization molecules for the synthesis of Ag–AuNPs. While leaf, seed and seed shell extract-mediated Ag–AuNPs had near spherical morphology, anisotropic structures of sphere, rod, hexagon and triangle were formed by pod extract. The polydispersed particles were 17–91 nm in size, with crystalline characteristics and prominent presence of Ag and Au in the EDX spectra. Ag–AuNPs inhibited growth of Aspergillus flavus, A. fumigatus and A. niger by 69.51–100 %. Exposure of Anopheles mosquito larvae to Ag–AuNPs resulted in 80–100 % mortality in 24 h. Catalytic degradation of >90 and >60 % were obtained for malachite green and methylene blue respectively after 24 h. The particles displayed potent blood anticoagulant and thrombolytic activities, indicative of their potentials in the management blood coagulation disorders. This study showed that C. nitida can be used for green synthesis of Ag–AuNPs, which is the first report of its kind.  相似文献   

9.
A new three-dimensional platinum(II)–thallium(I) coordination polymer [{Pt(pda)(NHCOtBu)2}4Tl4][Pt(CN)4]2·2H 2 O (pda = 1,2-propyldiamine) has been prepared from the direct reaction of [Tl2Pt(CN)4] and [Pt(pda)(NHCOtBu)2] in water, and its structure was characterized by X-ray diffraction analysis. The compound crystallizes in monoclinic, space group Pn, a = 11.567(2) Å, b = 11.570(2) Å, c = 37.677(8)Å, β = 94.64(3)°, V = 5025.8(17) Å3, Z = 2, R1 = 0.0679 and wR2 = 0.1574 [I >  2σ (I)], Goodness-of-fit on F 2 = 1.055. The compound exhibits a novel 3D network structure consisting of [Pt(CN)4]2? connected 1D infinite Pt–Tl–Pt–Tl chains via strong Pt–Tl bonds.  相似文献   

10.
Methylobacterium extorquens AM1 is the model strain for methylotrophic bacteria that metabolize methanol as the sole carbon and energy source. Genetically modified M. extorquens AM1 is used as a methylotrophic cell factory (MeCF) for high value-added chemical production. We tested the Cre-loxP recombination system for its ability to mediate multicopy gene integration of the mvt3 operon (mvt3) in M. extorquens AM1. mvt3 controls the expression of the first three enzymes of the mevalonate synthesis pathway. We assayed for Cre-mediated multigene integration by screening for multicopy mutants via their survival in culture with a high kanamycin concentration (600 μg/mL). We identified mutant strains in which the mevalonate titer was increased by up to 1.9-fold compared with M2 (M. extorquens AM1ΔcelABCΔattTn7::mvt3::loxP) and confirmed mvt3 integration at 2–3 copies per genome. This result demonstrates the feasibility of multicopy integration in M. extorquens AM1 mediated by Cre-loxP recombination and its potential for improving the output of M. extorquens AM1 metabolic pathways, e.g., optimization of terpenoid synthesis.  相似文献   

11.
Preliminary testing of dissolved air flotation (DAF) for wastewater treatment is presented. A combined coagulation-flocculation/DAF column system is used to remove oil and 60Co from nuclear industry wastewater. In this work, operational conditions and coagulant/flocculant concentrations are optimized by varying pH. Determinations of air-solids ratio (G/S), retention time (θ), pressure (P), volume of depressurized air–water mixture (V), turbidity and 60Co concentrations are reported. The effect of the treatment on the efficiency of separation of oily residues is also discussed. The results establish that the coagulant/flocculant system, formed by a modified polyamine (25 mgL?1) and a slightly cationic polyacrylamide (1.5 mgL?1), under specific operational conditions (pH = 7, mixing intensity Im1 = 300 s?1 and Im2 = 30 s?1), allowed the destabilization of colloidal matter, resulting in resistant flocs. It was concluded that by using G/S = 0.3, θ = 15 min, P = 620 kPa and V = 0.0012 m3, the greatest percentage removals of oil, turbidity, total cobalt and 60Co were obtained. These preliminary results then show that dissolved air flotation represents a good alternative for treatment of nuclear industry wastewater contaminated with radionuclides.  相似文献   

12.
The structure of bis(N,N,N′,N′-tetramethylthiophosphoramidoyl)-methylamine 1 has been determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the monoclinic system, with a space group P21/c, a = 11.836(2) Å, b = 11.659(2) Å, c = 12.796(5) Å and β = 95.28(3)°, V = 1758.3(5) Å3 and Z = 4. The X-ray crystallographic data have been assessed by semi-empirical and ab-initio density functional theory and by Hartree–Fock molecular orbital methods. A comparative study of the results of the different methods is given.  相似文献   

13.
Densities ρ and viscosities η were measured for the binary mixtures of ethylenediamine (EDA) and ethylene glycol (EG) in the temperature range 288.15–323.15 K for ρ and at 273.15–323.15 K for η, both of which are broader temperature ranges than those reported previously. The value of ρ monotonously decreases against the mole fraction of EDA, x EDA, and increasing temperature. The concentration dependence of η exhibits a maximum in the intermediate concentration range at all temperatures measured. The glass transition temperature, T g, for samples with x EDA < 0.7 was measured using differential scanning calorimetry. The measured T g values show a peak in the intermediate concentration range, which is a behavior similar to that of η; however, the peak concentrations for η and T g did not precisely align because of a deviation in the maximum hydrogen-bond density. The partial molar volumes for EDA and EG and the thermal expansivities, α, were obtained from ρ. Results in the present study are discussed in terms of the extensively increasing hydrogen-bond density for polyamine–polyhydric alcohol systems.  相似文献   

14.
An approximate analytical solution of the Schrödinger equation is obtained to represent the rotational–vibrational (ro-vibrating) motion of a diatomic molecule. The ro-vibrating energy states arise from a systematical solution of the Schrödinger equation for an empirical potential (EP) V ±(r) = D e {1 ? (?/δ)[coth (ηr)]±1/1 ? (?/δ)}2 are determined by means of a mathematical method so-called the Nikiforov–Uvarov (NU). The effect of the potential parameters on the ro-vibrating energy states is discussed in several values of the vibrational and rotational quantum numbers. Moreover, the validity of the method is tested with previous models called the semiclassical (SC) procedure and the quantum mechanical (QM) method. The obtained results are applied to the molecules H2 and Ar2.  相似文献   

15.
Two napelline skeletal diterpenoid alkaloids 15-acetylsongorine, C24H33NO4 I, and songoramine, C22H29NO3 II, were first isolated from the roots of Aconitum Szechenyianum Gay. The crystal structures were determined by X-ray single-crystal diffraction analysis. The crystal I is the triclinic system with space group P1 having unit cell parameters of a = 9.360(8) Å, b = 11.593(9) Å, = 11.830(16) Å, α = 113.223(15)°, β = 105.950(16)°, γ = 101.296(12)°, and Z = 2. Hydrogen bonds O–H···O and O–H···N joint the molecules into dimer. The crystal II belongs to the orthorhombic system with space group P212121 having unit cell parameters of a = 8.950(2) Å, = 13.272(3) Å, = 15.454(4) Å and Z = 4. The O–H···O hydrogen bonding interaction links the molecule into linear chains. The distortion of rings of compound I and II were evaluated by calculation of the Cremer and Pople puckering parameters. The presence of the C–O–C bond in the compound II results in the changes of ring conformations compared with that of the compound I.  相似文献   

16.
Production of fumaric acid from alkali-pretreated corncob (APC) at high solids loading was investigated using a combination of separated hydrolysis and fermentation (SHF) and fed-batch simultaneous saccharification and fermentation (SSF) by Rhizopus oryzae. Four different fermentation modes were tested to maximize fumaric acid concentration at high solids loading. The highest concentration of 41.32 g/L fumaric acid was obtained from 20 % (w/v) APC at 38 °C in the combined SHF and fed-batch SSF process, compared with 19.13 g/L fumaric acid in batch SSF alone. The results indicated that a combination of SHF and fed-batch SSF significantly improved production of fumaric acid from lignocellulose by R. oryzae than that achieved with batch SSF at high solids loading.  相似文献   

17.
The quantum mechanics of a diatomic molecule in a noncentral potential of the type V (r) = V θ (θ)/r 2 + V r (r) are investigated analytically. The θ-dependent part of the relevant potential is suggested for the first time as a novel angle-dependent (NAD) potential \({V_{\theta}(\theta)=\frac{\hbar^2}{2\mu}\left(\frac{\gamma +\beta \sin^2\theta +\alpha \sin^4 \theta}{\sin^2\theta \cos^2\theta}\right)}\) and the radial part is selected as the Coulomb potential or the harmonic oscillator potential, i.e., V r (r) =  ? H/r or V r (r) = Kr 2, respectively. Exact solutions are obtained in the Schrödinger picture by means of a mathematical method named the Nikiforov–Uvarov (NU). The effect of the angle-dependent part on the solution of the radial part is discussed in several values of the NAD potential’s parameters as well as different values of usual quantum numbers.  相似文献   

18.
The present study reports the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution using leaf extracts of Commiphora caudata. The formation of Ag NPs in the colloidal solution is confirmed by UV–Vis spectroscopy analysis. The identification of biomolecules is analyzed through fourier transform infrared spectroscopy. X-ray diffraction pattern shows that an average particle size of the synthesized nanoparticles are in the range of 40–24 nm. Field emission scanning electron microscopy and transmission electron microscopy confirm the formation Ag NPs in spherical shape. The photoluminescence study of the synthesized Ag NPs interprets the influence of C caudata leaf concentrations on emission behavior. Zeta potential measurement is carried out to determine the stability of synthesized Ag NPs. GC–MS analysis revealed that the C. caudata contained 11 compounds, such as Stigmasterol (24.14 %), Hexacosanoic acid, methyl ester (15.13 %) and 2-bromophenyl morpholine-4-carboxylate (11.71 %). The antibacterial activity of Ag NPs shows that these bio capped Ag NPs have higher inhibitory action for Escherichia coli, Klebsiella pheumoniea, Micrococcus flavus, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus pumilus, Staphylococcus aureus.  相似文献   

19.
Power characteristics for an agitated vessel equipped with planar short baffles of length L and pitched blade turbine of pitch β are presented in the paper. The studies were carried out in the vessel of inner diameter D = 0.6 m, where the baffles were located in the distance p from the vessel bottom (p + L = H). Torque was measured using strain gauge method within the turbulent regime of the flow of Newtonian liquid in the agitated vessel. The effects of the pitch β and geometrical parameter p/H on the power number Ne were determined mathematically. The results showed that, for the assumed value of the angle β, the function Ne = f (L/H) decreases with the decrease in the baffle length L (i.e. with the increase in the parameter p). Moreover, for the assumed value of the baffle length L, the function Ne = f (β) increases with the increase in the angle β of the inclination of the impeller blade.  相似文献   

20.
To increase the biocatalytic activity of Escherichia coli CCZU-T15 whole cells, choline chloride/glycerol ([ChCl][Gly]) was firstly used as biocompatible solvent for the effective biotransformation of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE]. Furthermore, L-glutamine (150 mM) was added into [ChCl][Gly]–water ([ChCl][Gly] 12.5 vol%, pH 6.5) media instead of NAD+ for increasing the biocatalytic efficiency. To further improve the biosynthesis of (S)-CHBE (>99 % e.e.) by E. coli CCZU-T15 whole cells, Tween-80 (7.5 mM) was also added into this reaction media, and (S)-CHBE (>9 % e.e.) could be effectively synthesized from 2000 and 3000 mM COBE in the yields of 100 and 93.0 % by whole cells of recombinant E. coli CCZU-T15, respectively. TEM image indicated that the cell membrane was permeabilized and lost its integrity and when the cell was exposed to [ChCl][Gly]–water media with Tween-80. Clearly, this bioprocess has high potential for the effective biosynthesis of (S)-CHBE (>99 % e.e.).  相似文献   

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