Characterization of purified fungal endoxylanase and its application for production of value added food ingredient from agroresidues

Xylanase from Aspergillus foetidus MTCC 4898 was purified using ammonium sulphate fractionation followed by ion exchange and gel permeation chromatography with 12.26-fold purity and 29.9% recovery. Purified xylanase was found to be 29.9 kDa. Optimum temperature and pH for xylanase activity of purified xylanase were found to be 50 °C and 5.3 respectively. Presence of additives like polyethylene glycol, sodium azide, Tween 80, KCl and NaCl increased the stability of purified xylanase by 35, 29, 28, 32 and 43% respectively at 50 °C after 180 min. Kinetic parameters like K_m and V_max were found to be 4 mg/ml and 7288 μmol/mg/min respectively. The purified xylanase was found to be an endoxylanase as it produced only xylooligosaccharides (XOS) from birchwood xylan. Production of XOS was carried out from xylan extracted from agro-residues using β-xylosidase free xylanase. Maximum yield of XOS was 7.28 ± 0.14 mg/ml and 4.52 ± 0.21 mg/ml from wheat straw xylan and rice straw xylan respectively. XOS mixture was suitable for food industry looking at its high thermal stability at low pH. Prebiotic effect of XOS was evaluated by in vitro fermentation of XOS using known probiotic strains of Bifidobacterium spp.     

Kinetics,Thermodynamics, and Isothermic Evaluation in Sorption Study of Hazardous Dye Using Sodium Dodecylsulfate Physically Impregnated in Polyester‐Type Polyurethane Foam

Use of polyester‐type polyurethane foam (PUF) is an effective adsorbent for the removal of hazardous dye: crystal violet (CV) from an aqueous solution. In this adsorption study, the formation of hydrophobic ion pair (opposite charge attraction) between the charged species, i.e., cationic (basic) dye CV and anionic surfactant sodium dodecylsulfate (SDS) sorbed onto PUF. Chemical calculations were performed using quantum simulation to understand ion‐pair formation for CV–SDS at the semiempirical PM6 level. Adsorption studies were performed using 200 mg cylindrical PUF with an overhead stirrer in solutions containing varying compositions of the dye–surfactant mixture. The equilibrium thermodynamics and kinetics of the adsorption process were studies by measuring CV dye removal as a function of time and temperature. Results show that the formation of the dye–surfactant ion pair is necessary for effective adsorption onto PUF. Various adsorption isotherms, viz., Langmuir, Freundlich, Temkin, Dubinin–Radushkevich (DRK), Harkin‐Jura, and several kinetic models, viz., pseudo‐first order, pseudo‐second order, Elovich, and Intraparticle diffusion were used to fit the spectrophotometric result. The equilibrium adsorption data fit to the Langmuir isotherm gives the maximum adsorption of PUF as 33.39 mg g^?1 from 200 mL 5.0 × 10^?5 mol L^?1 CV solution at 298.15 K. The kinetics study showed that the overall adsorption process follows pseudo‐second‐order kinetics. The Morris–Weber model suggests that an intraparticle diffusion process is active in controlling the adsorption rate. The Freundlich, Temkin, DRK adsorption isotherms showed that solute dye transfers from solution to the PUF adsorbent surface through physical adsorption. The Langmuir and Harkin‐Jura adsorption isotherms suggest that the adsorbent surface is homogeneous in nature. The thermodynamic data showed that the adsorption process is spontaneous and endothermic with a positive enthalpy change and a negative change in Gibb's energy.     

An Indian test facility to characterise diagnostic neutral beam for ITER

The diagnostic neutral beam (DNB) line shall be used to diagnose the He ash content in the D–T phase of the ITER machine using the charge exchange recombination spectroscopy (CXRS). Implementation of a successful DNB at ITER requires several challenges related to the production, neutralization and transport of the neutral beam over path lengths of 20.665 m, to be overcome. The delivery is aided if the above effects are tested prior to onsite commissioning. As DNB is a procurement package for INDIA, an ITER approved Indian test facility, INTF, is under construction at Institute for Plasma Research (IPR), India and is envisaged to be operational in 2015. The timeline for this facility is synchronized with the RADI, ELISE (IPP, Garching), SPIDER (RFX, Padova) in a manner that best utilization of configurational inputs available from them are incorporated in the design. This paper describes the facility in detail and discusses the experiments planned to optimise the beam transmission and testing of the beam line components using various diagnostics.     

A renewable approach toward the development of mahua oil‐based wood protective polyurethane coatings: Synthesis and performance evaluation

In the current scenario, the demand for renewable resources is increasing day by day due to numerous factors. In view of this, current work represents the preparation of wood protective polyurethane (PU) coatings from mahua oil. Mahua oil was used as a starting material for the synthesis of fatty amide by base catalyzed aminolysis reaction. The synthesized fatty amide was converted into the polyetheramide polyols by a condensation reaction with bisphenol C. The structure of the synthesized products was confirmed by the attenuated total reflection‐Fourier transform infrared and ¹H‐NMR spectroscopy. The synthesized polyetheramide polyols were used as precursors for the preparation of PUs and the prepared PUs were applied on the wood surface as a protective coating. The coating performance of the PUs was evaluated by the measurement of mechanical, thermal, and microbial properties as well as water, solvent, and chemical resistance. The coating performance revealed that mahua oil can be used as a renewable resource for the preparation of wood protective PUs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46722.     

Biosynthesis of silver nanoparticles by Pseudomonas spp. isolated from effluent of an electroplating industry

The aim of this study was to isolate and screen bacteria from soil and effluent of electroplating industries for the synthesis of silver nanoparticles and characterize the potential isolate. Soil and effluent of electroplating industries from Mumbai were screened for bacteria capable of synthesizing silver nanoparticles. From two soils and eight effluent samples 20 bacterial isolates were obtained, of these, one was found to synthesize silver nanoparticles. Synthesis of silver nanoparticle by bacteria was confirmed by undertaking characterization studies of nanoparticles that involved spectroscopy and electron microscopic techniques. The potential bacteria was found to be Gram‐negative short rods with its biochemical test indicating Pseudomonas spp. Molecular characterization of the isolate by 16S r DNA sequencing was carried out which confirmed its relation to Pseudomonas hibiscicola ATCC 19867. Stable nanoparticles synthesized were 50 nm in size and variable shapes as seen in SEM micrographs. The XRD and FTIR confirmed the crystalline structure of nanoparticles and presence of biomolecules mainly proteins as agents for reduction and capping of nanoparticles. The study demonstrates synthesis of nanoparticles by bacteria from effluent of electroplating industry. This can be used for large scale synthesis of nanoparticles by cost effective and environmentally benign mode of synthesis.Inspec keywords: biotechnology, effluents, soil, biochemistry, scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, nanoparticles, electroplatingOther keywords: environmentally benign mode, large‐scale nanoparticles synthesis, proteins, biomolecules, Fourier transform infrared spectroscopy, X‐ray diffraction, SEM micrographs, pseudomonas hibiscicola ATCC 19867, 16S rDNA sequencing, molecular characterisation, biochemical test, gram‐negative short rods, potential bacteria, spectroscopy, electron microscopic techniques, soil, electroplating industries, effluent, pseudomonas spp, silver nanoparticles biosynthesis     

Influence of pressurized carbon dioxide on ketoprofen-incorporated hot-melt extruded low molecular weight hydroxypropylcellulose

Objectives: The aim of the current research project was to investigate the effect of pressurized carbon dioxide (P-CO₂) on the physico-mechanical properties of ketoprofen (KTP)-incorporated hydroxypropylcellulose (HPC) (Klucel? ELF, EF, and LF) produced using hot-melt extrusion (HME) techniques and to assess the plasticization effect of P-CO₂ on the various polymers tested.

Methods: The physico-mechanical properties of extrudates with and without injection of P-CO₂ were examined and compared with extrudates with the addition of 5% liquid plasticizer of propylene glycol (PG). The extrudates were milled and compressed into tablets. Tablet characteristics of the extrudates with and without injection of P-CO₂ were evaluated.

Results and conclusion: P-CO₂ acted as a plasticizer for tested polymers, which allowed for the reduction in extrusion processing temperature. The microscopic morphology of the extrudates was changed to a foam-like structure due to the expansion of the CO₂ at the extrusion die. The foamy extrudates demonstrated enhanced KTP release compared with the extrudates processed without P-CO₂ due to the increase of porosity and surface area of those extrudates. Furthermore, the hardness of the tablets prepared by foamy extrudates was increased and the percent friability was decreased. Thus, the good binding properties and compressibility of the extrudates were positively influenced by utilizing P-CO₂ processing.     

Design optimization of the 100 kV HV bushing for ITER-DNB

The 100 kV bushing of the Diagnostic Neutral Beam (DNB) injector is a cylindrical feedthrough which forms the interface between the gas insulated transmission line and the torus primary vacuum and provides all necessary services to the beam source. All conventions for safety, voltage holding requirement, vacuum compatibility and the choice of materials have been addressed in the design. Finite Element Analyses (FEAs) for the electrostatic and the structural configuration is carried out to validate the design of the High Voltage Bushing (HVB). Several iterations and optimizations of the stress shields are carried out to meet electrostatic criteria, especially at the triple point (the ceramic, metal and vacuum joint), which is critical for good voltage holding. Structural analyses is carried out to assess the stress distribution in the fiber reinforced plastic insulator, the alumina insulator and the integrated HVB for different load cases like operational orientation (horizontal), normal operation and accidental case. Design is further validated for seismic conditions for Seismic Loading-2 (SL-2).     

In Situ Ophthalmic Gel of Ciprofloxacin Hydrochloride for Once a Day Sustained Delivery

This article focuses on preparation and evaluation of a once a day ophthalmic delivery system for ciprofloxacin hydrochloride based on the concept of pH-triggered in situ gelation. The in situ gelling system involves the use of polyacrylic acid (Carbopol® 980NF) as a phase transition polymer, hydroxypropyl methylcellulose (Methocel® K100LV) as a release retardant, and ion exchange resin as a complexing agent. Ciprofloxacin hydrochloride was complexed with ion exchange resin to avoid incompatibility between drug and polyacrylic acid. The developed formulation was stable, and nonirritant to rabbit eyes and in vitro drug release was found to be around 98% over a period of 24 hours.     

Study of microhardness and electrical properties of proton irradiated polyethersulfone (PES)

Polyethersulfone (PES) films were irradiated with 3 MeV proton beams in the fluence range 10¹³–10¹⁵ ions/cm². The radiation induced changes in microhardness was investigated by a Vickers’ microhardness tester in the load range 100–1000 mN and electrical properties in the frequency range 100 Hz-1 MHz by an LCR meter. It is observed that microhardness of the film increases significantly as fluence increases up to 10¹⁴ ions/cm². The bulk hardness of the films is obtained at a load of 400 mN. The increase in hardness may be attributed to the cross linking effect. There is an exponential increase in conductivity with log frequency and the effect of irradiation is significant at higher fluences. The dielectric constant/loss is observed to change significantly due to irradiation. It has been found that dielectric response in both pristine and irradiated samples obey the Universal law and is given by ɛ ∝ f ⁿ⁻¹. These results were corroborated with structural changes observed in FTIR spectra of irradiated samples.