Hard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5-10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.
Deltamethrin resistance in Laodelphax striatellus had been associated with its oxidative detoxification by overexpression of four cytochrome P450 monooxygenases like CYP353D1v2, CYP6FU1, CYP6AY3v2, and CYP439A1v3. The first three P450s have been validated for insecticide-metabolizing capability and only CYP6FU1 was found to degrade deltamethrin. In this study, an investigation was conducted to confirm the capability of CYP439A1v3 to degrade deltamethrin. The CYP439A1v3 was first expressed in Sf9 cell line and its recombinant enzyme was tested for metabolic activity against different insecticides using substrate depletion assay combined with metabolite identification. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and carbon monoxide (CO)-difference spectra analysis showed that the intact cytochrome P450 protein was successfully expressed. Tests with probe substrates proved its enzyme activity, as p-nitroanisole, ethoxycoumarin, and ethoxyresorufin were preferentially metabolized (specific activity 7.767 ± 1.22, 1.325 ± 0.37, and 0.355 ± 0.37 nmol/min per mg of protein, respectively) while only luciferin-HEGE was not. In vitro incubation of the recombinant CYP439A1v3 protein with deltamethrin revealed hydroxylation by producing hydroxydeltamethrin. On the contrary, no metabolite/metabolism was seen with nonpyrethroid insecticide, including imidacloprid, buprofezin, chlorpyrifos, and fipronil. To the best of our knowledge, this is the first study to link a CYP450 from family 439 to confer pyrethroid resistance to L. striatellus. This finding should help in the design of appropriate insecticide resistance management for control of this strain of L. striatellus.
Sustainable materials, such as vegetable oils, have become an effective alternative for liquid dielectrics in power transformers. However, currently available vegetable oils for transformer application are extracted from edible products with a negative impact on food supply. So, it is proposed in this study to develop cottonseed oil (CSO) as an electrical insulating material and cooling medium in transformers. This development is performed in two stages. The first stage is to treat CSO with tertiary butylhydroquinone (TBHQ) antioxidants in order to enhance its oxidation stability. The second and most important stage is to use the promising graphene oxide (GO) nanosheets to enhance the dielectric and thermal properties of such oil through synthesizing GO-based CSO nanofluids. Sodium dodecyl sulfate (SDS) surfactant was used as surfactant for GO nanosheets. The nanofluid synthesis process followed the two-step method. Proper characterization of GO nanosheets and prepared nanofluids was performed using various techniques to validate the structure of GO nanosheets and their stability into the prepared nanofluids. The considered weight percentages of GO nanosheets into CSO are 0.01, 0.02, 0.03 and 0.05. Dielectric and thermal properties were comprehensively evaluated. Through these evaluations, the proper weight percentage of GO nanosheets was adopted and the corresponding physical mechanisms were discussed.
Micellar properties of binary mixed surfactants of a surface active mixed copper(II) chelate, [Cu(C12-tmed)(acac)Cl] (where C12-tmed is N,N,N'-trimethyl-N'-dodecylethylenediamine) with three common surfactants, viz. sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and octaethylene glycol monododecyl ether (C12E8), were investigated by surface tensiometry, ESR, and UV-visible absorption techniques. The surface tension data were treated with Rubingh's method for mixed micelle formation and Rosen's method for mixed monolayer formation at the aqueous solution/air interface. It was found that in the mixed micelle there is strong attractive interaction between cationic copper surfactant and anonic dodecyl sulfate while there is almost ideal mixing between copper surfactant and CTAB and C12E8. From the ESR and UV-visible studies, a mixed block-type arrangement of head groups is proposed. Copyright 1997 Academic Press. Copyright 1997Academic Press
The aim of this work is to convert agroforestry residue to a novel adsorbent (M-1CTA-SDS-BT) used for adsorptive benzene sequestration from aqueous solution. In this study, the anionic surfactant-coated-cationized banana trunk was synthesized and characterized for batch adsorption of benzene from aqueous solution. The surface morphology, surface chemistry, surface area, and pore properties of the synthesized adsorbents were examined. It was proven that surface cationization successfully increased the benzene adsorption capacity of sodium dodecyl sulfate-coated adsorbents. The Langmuir isotherm model satisfactorily described the equilibrium adsorption data. The maximum benzene adsorption capacity (qmax) of 468.19 μmol/g was attained. The kinetic data followed the pseudo-second-order kinetic model in which the rate-limiting step was proven to be the film diffusion. The batch-adsorbent regeneration results indicated that the M-1CTA-SDS-BT could withstand at least five adsorption/desorption cycles without drastic adsorption capacity reduction. The findings demonstrated the adsorptive potential of agroforestry-based adsorbent as a natural and cheap material for benzene removal from contaminated water.
A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) technique has been developed for enantioseparation of vinpocetine using an inexpensive 2-hydroxypropyl-β-CD (HP-β-CD) as the chiral selector (CS). The best chiral separation was achieved using 40 mM HP-β-CD as the CS in 50 mM phosphate buffer (pH 7.0) consisting of 40 mM sodium dodecyl sulfate (SDS) at a separation temperature and separation voltage of 25°C and 25 kV, respectively. To the author's best knowledge, this is the first CD-MEKC study able to successfully separate the four stereoisomer of vinpocetine in separation time of 9.5 min and resolution of 1.04-3.87.
Colloidal gas aphron dispersions (CGAs) can be described as a system of microbubbles suspended homogenously in a liquid matrix. This work examines the performance of CGAs in comparison to surfactant solutions for washing low levels of arsenic from an iron rich soil. Sodium Dodecyl Sulfate (SDS) and saponin, a biodegradable surfactant, obtained from Sapindus mukorossi or soapnut fruit were used for generating CGAs and solutions for soil washing. Column washing experiments were performed in down-flow and up flow modes at a soil pH of 5 and 6 using varying concentration of SDS and soapnut solutions as well as CGAs. Soapnut CGAs removed more than 70% arsenic while SDS CGAs removed up to 55% arsenic from the soil columns in the soil pH range of 5-6. CGAs and solutions showed comparable performances in all the cases. CGAs were more economical since it contains 35% of air by volume, thereby requiring less surfactant. Micellar solubilization and low pH of soapnut facilitated arsenic desorption from soil column. FT-IR analysis of effluent suggested that soapnut solution did not interact chemically with arsenic thereby facilitating the recovery of soapnut solution by precipitating the arsenic. Damage to soil was minimal arsenic confirmed by metal dissolution from soil surface and SEM micrograph.
ZnO nanostructures were synthesized by hydrothermal method using different molar ratios of cetyltrimethylammonium bromide (CTAB) and Sodium dodecyl sulfate (SDS) as structure directing agents. The effect of surfactants on the morphology of the ZnO crystals was investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The results indicate that the mixture of cationic-anionic surfactants can significantly modify the shape and size of ZnO particles. Various structures such as flakes, sheets, rods, spheres, flowers and triangular-like particles sized from micro to nano were obtained. In order to examine the possible changes in other properties of ZnO, characterizations like powder X-ray diffraction (PXRD), thermogravimetric and differential thermogravimetric analysis (TGA-DTG), FTIR, surface area and porosity and UV-visible spectroscopy analysis were also studied and discussed.
The separation of enantiomers is one of the important fields of modern analytical chemistry, especially for agrochemical and pharmaceutical products because the stereochemistry has a significant influence on the biological activities of compounds. Cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) has become an important capillary electrophoresis mode for enantioseparations. Here, we describe an example of a CD-MEKC method using hydroxypropyl-γ-cyclodextrin as chiral selector and sodium dodecyl sulfate as micellar solution for enantioseparation of triazole fungicides and the drug econazole.
Sodium dodecyl sulfate (SDS) is one of the main components in the detergent and cosmetic industries. Its bioremediation by suitable microorganism has begun to receive greater attention as the amount of SDS usage increases to a point where treatment plants would not be able to cope with the increasing amount of SDS in wastewater. The purpose of this work was to isolate local SDS-degrading bacteria. Screening was carried out by the conventional enrichment-culture technique. Six SDS-degrading bacteria were isolated. Of these isolates, isolate S14 showed the highest degradation of SDS with 90% degradation after three days of incubation. Isolate S14 was tentatively identified as Klebsiella oxytoca strain DRY14 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. SDS degradation by the bacterium was optimum at 37 degrees 0. Ammonium sulphate; at 2.0 g l(-1), was found to be the best nitrogen source for the growth of strain DRY14. Maximum growth on SDS was observed at pH 7.25. The strain exhibited optimum growth at SDS concentration of 2.0 g l(-1) and was completely inhibited at 10 g l(-1) SDS. At the tolerable initial concentration of 2.0 g l(-1), almost 80% of 2.0 g l(-1) SDS was degraded after 4 days of incubation concomitant with increase in cellular growth. The K(m(app) and V(max(app)) values calculated for the alkylsulfatase from this bacterium were 0.1 mM SDS and 1.07 micromol min(-1) mg(-1) protein, respectively.
This work aimed to develop a chiral separation method of ketoconazole enantiomers using electrokinetic chromatography. The separation was achieved using heptakis (2, 3, 6-tri-O-methyl)-β-cyclodextrin (TMβCD), a commonly used chiral selector (CS), as it is relatively inexpensive and has a low UV absorbance in addition to an anionic surfactant, sodium dodecyl sulfate (SDS). The influence of TMβCD concentration, phosphate buffer concentration, SDS concentration, buffer pH, and applied voltage were investigated. The optimum conditions for chiral separation of ketoconazole was achieved using 10 mM phosphate buffer at pH 2.5 containing 20 mM TMβCD, 5 mM SDS, and 1.0% (v/v) methanol with an applied voltage of 25 kV at 25 °C with a 5-s injection time (hydrodynamic injection). The four ketoconazole stereoisomers were successfully resolved for the first time within 17 min (total analysis time was 28 min including capillary conditioning). The migration time precision of this method was examined to give repeatability and reproducibility with RSDs ≤5.80% (n =3) and RSDs ≤8.88% (n =9), respectively.
A bacterium capable of biodegrading surfactant sodium dodecyl sulphate (SDS) was isolated from Antarctic soil. The isolate was tentatively identified as Pseudomonas sp. strain DRY15 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Growth characteristic studies showed that the bacterium grew optimally at 10 degrees C, 7.25 pH, 1 g l(-1) SDS as a sole carbon source and 2 g l(-1) ammonium sulphate as nitrogen source. Growth was completely inhibited at 5 g l(-1) SDS. At a tolerable initial concentration of 2 g l(-1), approximately 90% of SDS was degraded after an incubation period of eight days. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibition with a correlation coefficient value of 0.97. The maximum growth rate was 0.372 hr(-1) while the saturation constant or half velocity constant (Ks) and inhibition constant (Ki), were 0.094% and 11.212 % SDS, respectively. Other detergent tested as carbon sources at 1 g l(-1) was Tergitol NP9, Tergitol 15S9, Witconol 2301 (methyl oleate), sodium dodecylbenzene sulfonate (SDBS), benzethonium chloride, and benzalkonium chloride showed Tergitol NP9, Tergitol 15S9, Witconol 2301 and the anionic SDBS supported growth with the highest growth exhibited by SDBS.
Gelatin from salmon (Salmo salar) skin with high molecular weight protein chains (α-chains) was extracted using trypsin-aided process. Response surface methodology was used to optimise the extraction parameters. Yield, hydroxyproline content and protein electrophoretic profile via sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of gelatin were used as responses in the optimization study. The optimum conditions were determined as: trypsin concentration at 1.49 U/g; extraction temperature at 45 °C; and extraction time at 6 h 16 min. This response surface optimized model was significant and produced an experimental value (202.04 ± 8.64%) in good agreement with the predicted value (204.19%). Twofold higher yields of gelatin with high molecular weight protein chains were achieved in the optimized process with trypsin treatment when compared to the process without trypsin.
Zinc-air batteries are a promising technology for large-scale electricity storage. However, their practical deployment has been hindered by some issues related to corrosion and passivation of the zinc anode in an alkaline electrolyte. In this work, anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant Pluronic F-127 (P127) are examined their applicability to enhance the battery performances. Pristine zinc granules in 7 M KOH, pristine zinc granules in 0-8 mM SDS/7 M KOH, pristine zinc granules in 0-1000 ppm P127/7 M KOH, and SDS coated zinc granules in 7 M KOH were examined. Cyclic voltammograms, potentiodynamic polarization, and electrochemical impedance spectroscopy confirmed that using 0.2 mM SDS or 100 ppm P127 effectively suppressed the anode corrosion and passivation. Nevertheless, direct coating SDS on the zinc anode showed adverse effects because the thick layer of SDS coating acted as a passivating film and blocked the removal of the anode oxidation product from the zinc surface. Furthermore, the performances of the zinc-air flow batteries were studied. Galvanostatic discharge results indicated that the improvement of discharge capacity and energy density could be sought by the introduction of the surfactants to the KOH electrolyte. The enhancement of specific discharge capacity for 30% and 24% was observed in the electrolyte containing 100 ppm P127 and 0.2 mM SDS, respectively.
A halloysite nanotubes⁻polyvinyl alcohol⁻polyvinylpyrrolidone (HNTs⁻PVA⁻PVP) composite has been investigated for a quite long time aiming at improving the physico⁻chemical characterization of HNTs. In this work, HNTs⁻PVA⁻PVP composite were prepared based on a unique procedure characterized by crosslinking two polymers with HNTs. The composite of two polymers were modified by treating HNTs with phosphoric acid (H₃PO₄) and by using malonic acid (MA) as a crosslinker. The composite was also treated by adding the dispersion agent sodium dodecyl sulfate (SDS). The HNTs⁻PVA⁻PVP composite shows better characteristics regarding agglomeration when HNTs is treated in advance by H₃PO₄. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), brunauer⁻emmett⁻teller (BET), size distribution, and atomic force microscopy (AFM) are used to characterize the physio-chemical properties of the composite. FTIR shows additional peaks at 2924.29, 1455.7, and 682.4 cm-1 compared to the neat HNTs due to adding MA. Despite that, the XRD spectra do not show a significant difference, the decrease in peak intensity could be attributed to the addition of semi-crystalline PVA and the amorphous PVP. The images taken by TEM and FESEM show the possible effects of MA on the morphology and internal feature of HNTs⁻PVA⁻PVP composite treated by MA by showing the deformation of the matrix. The BET surface area increased to 121.1 m²/g compared to the neat HNTs at 59.1 m²/g. This result, the second highest recorded result, is considered a breakthrough in enhancing the properties of HNTs⁻PVA⁻PVP composite, and treatment by MA crosslinking may attribute to the size and the number of the pores. The results from these techniques clearly showed that a significant change has occurred for treated HNTs⁻PVA⁻PVP composite where MA was added. The characterization of HNTs⁻PVA⁻PVP composite with and without treating HNTs and using crosslinker may lead to a better understanding of this new composites as a precursor to possible applications in the dentistry field.
Oil palm is the major crop grown and cultivated in various Asian countries such as Malaysia, Indonesia and Thailand.
The core of oil palm trunk (COPT) consists of high sugar content, hence suitable for synthesis of fine chemicals and
biofuels. Increase of sugar content was reported previously during prolonged COPT storage. However, until now, there
has been no report on protein profiles during storage. Therefore, in this study, protein expression of the COPT during the
storage period of one to six weeks was investigated using sodium dodecyl sulphate polyacrylamide gel electrophoresis
(SDS-PAGE) coupled with optical density quantification and multivariate analyses for measuring differentially expressed
proteins. Accordingly, protein bands were subjected to tryptic digestion followed by tandem mass spectrometry (nanoLCMS/MS)
protein identification. The results from SDS-PAGE showed consistent protein bands appearing across the biological
replicates ranging from 10.455 to 202.92 kDa molecular weight (MW) regions. The findings from the principal component
analysis (PCA) plot illustrated the separation pattern of the proteins at weeks 4 and 5 of storage, which was influenced
mainly by the molecular weights of 14.283, 25.543, 29.757, 30.549, 31.511, 34.585 and 84.395 kDa, respectively. The
majority of these proteins are identified as those involved in stress- and defense-related, disease resistance, as well
as gene/protein expression processes. Indeed, these proteins were mostly upregulated during the later storage period
suggesting that long-term storage may influence the molecular regulation of COPT sap.
Poly-β-hydroxybutyrate (PHB) depolymerase is known to decompose PHB, biodegradable polymers and therefore has great commercial significance in the bioplastic sector. However, reports on PHB depolymerases from isolates obtained from plastic-contaminated sites that reflect the potential of the source organism is scarce. In this study, we evaluated the production of extracellular PHB depolymerase from Microbacterium paraoxydans RZS6 isolated from the plastic-contaminated site in the municipal area of Shahada, Maharashtra, India, for the first time. The isolate was identified using 16S rRNA gene sequencing, gas chromatographic analysis of fatty acid methyl esters (GC-FAME), and BIOLOG method. Ithydrolyzed PHB on minimal salt medium (MSM) containing PHB as the only source of carbon. The isolate produced PHB depolymerase at 45°C during 48 h of incubation. The enzyme was purified most efficiently using octyl-sepharose CL-4B column, with the highest purification yield of 6.675 Umg-1mL-1. The activity of the enzyme was enhanced in the presence of Ca2+ and Mg2+ ions but inhibited by Fe2+ (1 mM) ions and mercaptoethanol (1000 rpm). the nzyme kinetic analysis revealed that the enzyme was a metalloenzyme; requiring Mg2+ ions, that showed optimum enzyme activity at 30°C (mesophilic) and under neutrophilic (pH 7) conditions. Scale-up from the shake-flask level to a laboratory-scale bioreactor further enhanced the enzyme yield by 0.809 UmL-1. The molecular weight of the enzyme (40 kDa), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, closely resembled the PHB depolymerase of Aureobacterium saperdae. Our findings highlighted the applicability of M. paraoxydans as a producer of extracellular PHB depolymerase having potential of degrading PHB under diverse conditions.
MPT64 is a specific protein that is secreted by Mycobacterium tuberculosis complex (MTBC). The objective of this study was to obtain optimum culture conditions for MPT64 synthetic gene expression in Escherichia coli BL21 (DE3) by response surface methodology (RSM). The RSM was undertaken to optimize the culture conditions under different cultivation conditions (medium concentration, induction time and inducer concentration), designed by the factorial Box-Bhenken using Minitab 17 statistical software. From the randomized combination, 15 treatments and three center point repetitions were obtained. Furthermore, expression methods were carried out in the flask scale fermentation in accordance with the predetermined design. Then, the MPT64 protein in the cytoplasm of E. coli cell was isolated and characterized using sodium dodecyl sulfate polyacrilamide electrophoresis (SDS-PAGE) then quantified using the ImageJ program. The optimum conditions were two-fold medium concentration (tryptone 20 mg/mL, yeast extract 10 mg/mL, and sodium chloride 20 mg/mL), 5 h of induction time and 4 mM rhamnose. The average concentration of recombinant MPT64 at optimum conditions was 0.0392 mg/mL, higher than the predicted concentration of 0.0311 mg/mL. In conclusion, the relationship between the selected optimization parameters strongly influenced the level of MPT64 gene expression in E. coli BL21 (DE3).
The influence of an anionic surfactant, a cationic surfactant, and salinity on adsorbed methane (CH4) in shale was assessed and modeled in a series of systematically designed experiments. Two cases were investigated. In case 1, the crushed Marcellus shale samples were allowed to react with anionic sodium dodecyl sulfate (SDS) and brine. In case 2, another set of crushed Marcellus shale samples were treated with cetyltrimethylammonium bromide (CTAB) and brine. The surfactant concentration and salinity of brine were varied following the Box-Behnken experimental design. CH4 adsorption was then assessed volumetrically in the treated shale at varying pressures (1-50 bar) and a constant temperature of 30 °C using a pressure equilibrium cell. Mathematical analysis of the experimental data yielded two separate models, which expressed the amount of adsorbed CH4 as a function of SDS/CTAB concentration, salinity, and pressure. In case 1, the highest amount of adsorbed CH4 was about 1 mmol/g. Such an amount was achieved at 50 bar, provided that the SDS concentration is kept close to its critical micelle concentration (CMC), which is 0.2 wt %, and salinity is in the range of 0.1-20 ppt. However, in case 2, the maximum amount of adsorbed CH4 was just 0.3 mmol/g. This value was obtained at 50 bar and high salinity (∼75 ppt) when the CTAB concentration was above the CMC (>0.029 wt %). The findings provide researchers with insights that can help in optimizing the ratio of salinity and surfactant concentration used in shale gas fracturing fluid.