Biosorption of methylene blue dye using a novel chitosan pectinase blend.

Biosorption is a key phenomenon that has been used to remove the aquatic pollutants like dyes and heavy metals present in industrial effluents. The current study aims at the development of a chitosan-pectinase blend (CPB) to separate the methylene blue (MB) dye from its synthetic solution. Pectinase, an enzyme isolated from a consortium of Bacillus species, is imbibed in the blend. The electron micrographs revealed the rough surface of the adsorbent, and its amorphous nature was evident from broader peaks in diffraction patterns. The FTIR analyses indicated the perfect blend formation through the presence and shifts in the characteristic peaks. Maximum adsorption was exhibited at pH 7.0, 30 °C, 30 min of contact time and an adsorbent dosage of 2.5 g/L. On comparison, the pseudo-second-order model was found to be the suitable fit with the highest R2 value closer to 1. Different isotherm models were experimentally fitted and the maximum adsorption capacity was obtained at 16.81 mg/g and the Temkin isotherm suits the best. The polymer blend showed an agreeable extent of desorption of MB dye which was evident from the desorption studies and, thereby, the biosorbent could be reused for removing the dye to the maximum extent.

Modelling of urea hydrolysis kinetics using genetic algorithm coupled artificial neural networks in urease immobilized magnetite nanoparticles.

The presence of urea in runoff from fertilized soil could be contributing to the growth of dangerous blooms. Enzymatic urea hydrolysis is a well-known outstanding process that, when integrated with nanotechnology, would be much more efficient. This research provides a novel perspective on magnetic nanobiocatalysts that reduce diffusion barriers in effective urea hydrolysis. Surprisingly, the model developed with the use of a Genetic Algorithm (GA) and an Artificial Neural Network (ANN) demonstrated that the system's diffusion restrictions were reduced. In order to forecast accurate outputs using artificial intelligence (AI), a neural network with one hidden layer and 20 neurons was built utilizing multilayer feed-forward network and showed highest output (diffusion co-efficient) with least mean square error (MSE). The diffusion coefficients of free urease, urease immobilized onto porous MNs (U-aMNs), and nanobiocatalyst, i.e. urease immobilized onto surface modified MNs (U-MNß), were 1.9 × 10-17, 12.62 × 10-16, and 15.48 × 10-16 cm2/min, respectively. These results revealed that the addition of Chitosan to the surface of MNs had a considerable impact on enzyme dispersion. The decrease in Damkohler number (Da) from 2.37 ± 0.26 for U-aMNs to 2.19 ± 0.11 for U-MNß suggested a beneficial effect in overcoming diffusion constraints. Pseudo-first order and pseudo-second order models were used to analyze urea uptake kinetics, with the former model offering the best fit to the system, with R2 values that were much closer to unity.

Improvisation of diffusion coefficient in surface modified magnetite nanoparticles: A novel perspective.

Surface properties are inevitable in determining the properties of any support involved in tethering biomolecular moieties. Porous carriers impose numerous diffusional limitations and make the need for surface modification significant. To best of our knowledge, this study would be a new perspective on diffusional limitations in nanoparticles for the first time. Chitosan was aimed to alter the porosity of solvo-thermally synthesized magnetite nanoparticles (MNs) through surface coating. Various instrumental techniques were performed on chitosan, MNs, chitosan coated MNs (MNß) and urease tethered MNß (U-MNß) to reveal their behaviour. Maximum absorption with higher bandgap energy (2.76 eV) in visible spectrum, characteristic peaks in diffraction patterns and the presence of required peaks in Fourier transform infra-red (FT-IR) spectra suggested MNs synthesis and surface modification. Electron micrographs and Energy dispersive spectrum (EDS) showed surface variation and pure elemental composition of MNs respectively. Superparamagnetism and narrow size distribution were seen from magnetization curve with lower retentivity and Dynamic Light Scattering (DLS) respectively. Sorption profiles exhibited filling of pores on MNs and lower/higher diffusion co-efficient (De) were evaluated through respective conductivity measurements of free/tethered urease. The values of influencing parameters were optimized based on Box-Behnken design (BBD) matrix and the statistical analysis revealed that the optimum operating conditions for producing MNß. Hence change in surface porosity that enhanced activity of tethered enzyme through improved diffusion was achieved via surface coating.

Magnetic nanoparticles: a versatile carrier for enzymes in bio-processing sectors.

Many industrial processes experience the advantages of enzymes which evolved the demand for enzymatic technologies. The enzyme immobilisation technology using different carriers has trustworthy applications in industrial biotechnology as these techniques encompass varied advantages such as enhanced stability, activity along with reusability. Immobilisation onto nanomaterial is highly favourable as it includes almost all aspects of science. Among the various techniques of immobilisation, the uses of nanoparticles are remarkably well perceived as these possess high-specific surface area leading to high enzyme loadings. The magnetic nanoparticles (MNPs) are burgeoning in the field of immobilisation as it possess some of the unique properties such as high surface area to volume ratio, uniform particle size, biocompatibility and particularly the recovery of enzymes with the application of an external magnetic field. Immobilisation of industrially important enzymes onto nanoparticles offers overall combined benefits. In this review, the authors here focus on the current scenario in synthesis and functionalisation of MNPs which makes it more compatible for the enzyme immobilisation and its application in the biotechnological industries.

Prominent Study on Surface Properties and Diffusion Coefficient of Urease-Conjugated Magnetite Nanoparticles.

Herein, the magnetite nanoparticles (MNs) were prepared by facile solvothermal method and its porous nature was modified using 3-(2-aminoethyl)-3-aminopropyl trimethoxysilane (AEAPS). Magnetite formation, successful amino tagging, and urease conjugation on the surface were confirmed from the presence of certain functional groups in Fourier transform infrared (FT-IR) spectra. Also, nanosize (13.2 nm) and spherical morphology of MNs were evaluated from diffraction patterns and electron micrographs respectively. Lower retentivity and coercivities in magnetization curve revealed the superparamagnetic behavior, and nitrogen adsorption/desorption curves exhibited decrease in its surface porosity. Conductivity measurements showed lower diffusion coefficient (De = 1.9 × 10-17 cm2/min) and higher diffusion with limited hydrolytic reaction in native urease and improved activity of conjugated urease with higher De (12.62 × 10-16 cm2/min). Hence, this study revealed that the surface porous nature of MNs can be altered effectively by amino tagging in order to overcome diffusional limitations thereby enhancing enzyme activity.

Characterization, analysis, and application of fabricated Fe3O4-chitosan-pectinase nanobiocatalyst.

The investigation on fabrication of Fe3O4-chitosan-pectinase nanobiocatalyst was performed by covalently binding the pectinase onto carboxyl group activated chitosan-coated magnetic nanoparticles (CMNPs). The morphological and size distribution analysis of the different magnetic nanoparticles (MNPs) was done using transmission electron microscopy (TEM), and the average diameter was 11.07 ± 3.04, 11.55 ± 3.16, and 11.59 ± 3.16 nm for MNPs, CMNPs, and fabricated nanobiocatalyst, respectively, suggesting that there was no significant change in the size of MNPs after coating and binding. The characteristic peaks occurred at 2θ of 30.39, 35.43, 43.37, 57.22, and 62.9, and their corresponding indices 220, 311, 400, 520, and 441 for different MNPs from the X-ray diffraction (XRD) studies confirmed the presence of Fe3O4 with the spinel structure, and there was no phase change even after coating and binding. The various required characteristic absorption peaks (575, 585, 1,563, 1,614, 1,651, and 1,653 cm(-1)) from Fourier transform infrared (FT-IR) spectroscopy confirmed the surface modifications and binding of pectinase onto the MNPs. At the weight ratio of about 19.8 × 10(-3) mg bound pectinase/mg activated CMNPs, the activity of fabricated nanobiocatalyst was found to be maximum. In order to monitor their improved activity, the pH, temperature, reusability, storage ability, and kinetic studies were established.

Fabrication, characterization and application of pectin degrading Fe3O4-SiO2 nanobiocatalyst.

The covalent binding of pectinase onto amino functionalized silica-coated magnetic nanoparticles (CSMNPs) through glutaraldehyde activation was investigated for nanobiocatalyst fabrication. The average particle size and morphology of the nanoparticles were characterized using transmission electron microscopy (TEM). The statistical analysis for TEM image suggests that the coating and binding process did not cause any significant change in size of MNPs. The morphological and phase change of the magnetic nanoparticles (MNPs) after various coatings and immobilization were characterized by X-ray diffraction (XRD) studies. The various surface modifications and pectinase binding onto nanoparticles were confirmed by Fourier transform infrared (FT-IR) spectroscopy. The maximum activity of immobilized pectinase was obtained at its weight ratio of 19.0×10(-3) mg bound pectinase/mg CSMNPs. The pH, temperature, reusability, storage ability and kinetic studies were established to monitor their improved stability and activity of the fabricated nanobiocatalyst. Furthermore, the application was extended in the clarification of Malus domestica juice.