Purification of papain using reactive green 5 attached supermacroporous monolithic cryogel

PubMed ID: 22573009Supermacroporous poly(2-hydroxyethyl methacrylate) [poly(HEMA)] monolithic cryogel was prepared by radical cryocopolymerization of HEMA with N, N'-methylene bisacrylamide as crosslinker. Reactive Green 5 dye was immobilized to the cryogel with nucleophilic substitution reaction, and this dye attached cryogel column was used for affinity purification of papain from Carica papaya latex. Reactive Green 5-immobilized poly (HEMA) cryogel was characterized by swelling studies, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray analysis. Maximum papain adsorption capacity was found to be 68.5 mg/g polymer while nonspecific papain adsorption onto plain cryogel was negligible (3.07 mg/g polymer). Papain from C. papaya was purified 42-fold in single step with dye attached cryogel, and purity of papain was shown by silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis. © Springer Science+Business Media, LLC 2012

Immobilization of inulinase on concanavalin A-attached super macroporous cryogel for production of high-fructose syrup

PubMed ID: 23780342In this study, concanavalin A (Con A)-attached poly(ethylene glycol dimethacrylate) [poly(EGDMA)] cryogels were used for immobilization of Aspergillus niger inulinase. For this purposes, the monolithic cryogel column was prepared by radical cryocopolymerization of EGDMA as a monomer and N,N'-methylene bisacrylamide as a crosslinker. Then, Con A was attached by covalent binding onto amino-activated poly(EGDMA) cryogel via glutaraldehyde activation. Characterization of cryogels was performed by FTIR, EDX, and SEM studies. Poly(EGDMA) cryogels were highly porous and pore size was found to be approximately 50-100 µm. Con A-attached poly(EGDMA) cryogels was used in the adsorption of inulinase from aqueous solutions. Adsorption of inulinase on the Con A-attached poly(EGDMA) cryogel was performed in continuous system and the effects of pH, inulinase concentration, and flow rate on adsorption were investigated. The maximum amount of inulinase adsorption was calculated to be 27.85 mg/g cryogel at 1.0 mg/mL inulinase concentration and in acetate buffer at pH 4.0. Immobilized inulinase was effectively used in continuous preparation of high-fructose syrup. Inulin was converted to fructose in a continuous system and released fructose concentration was found to be 0.23 mg/mL at the end of 5 min of hydrolysis. High-fructose content of the syrup was demonstrated by thin layer chromatography. © 2013 Springer Science+Business Media New York

Reversible immobilization of urease by using bacterial cellulose nanofibers

PubMed ID: 24068477In this work, bacterial cellulose nanofibers were produced by using the Gluconacetobacter hansenii HE1 strain. These nanofibers were derivatized with dye affinity ligand Reactive Green 5, and these newly synthesized dye-attached nanofibers were used for affinity adsorption of urease. Reactive Green 5-attached nanofibers were characterized by Fourier transform infrared spectroscopy, SEM, and energy-dispersive x-ray spectroscopy analysis. Some adsorption conditions which significantly affect the adsorption efficiency were investigated. The maximum urease adsorption capacity was found to be 240 mg/g nanofiber in pH 6.0 and at room temperature. Dye-free plain nanofibers also used for studying nonspecific urease adsorption onto plain nanofibers and nonspecific adsorption were found to be negligible (3.5 mg/g nanofiber). Prepared dye-attached nanofibers can be used in five successive adsorption/desorption steps without any decrease in their urease adsorption capacity. The desorption rate of the adsorbed urease was found to be 98.9 %. The activity of the urease was also investigated, and it was found that free and desorbed urease from the dye-attached nanofibers showed similar specific activity. © Springer Science+Business Media New York 2013

Methacryloylamidohistidine in affinity ligands for immobilized metal-ion affinity chromatography of ferritin

A new metal-chelate adsorbent utilizing 2-methacryloylamidohistidine (MAH) was prepared as a metalchelating ligand. MAH was synthesized using methacryloly chloride and histidine. Monosize nanospheres with an average diameter of 450 nm were produced by emulsion polymerization of 2-hydroxyetylmethacrylate (HEMA) and MAH. Then, Fe 3+ ions were chelated directly onto the monosize nanospheres. Mon-poly(HEMA-MAH) nanospheres were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and elemental analysis. Fe 3+ chelated monosize nanospheres were used in ferritin adsorption from an aqueous solution. The maximum ferritin adsorption capacity of Fe 3+-chelated mon-poly(HEMA-MAH) nanospheres was 202 mg/g at pH 4.0 in acetate buffer. The non-specific ferritin adsorption on the monpoly(HEMA-MAH) nanospheres was 20 mg/g. The adsorption behavior of ferritin could be modeled using both Langmuir and Freundlich isotherms. The adsorption capacity decreased with increasing ionic strength of the binding buffer. High desorption ratios (> 95% of the adsorbed ferritin) were achieved with 1.0 M NaCl at pH 7.0. Ferritin could be repeatedly adsorbed and desorbed with the Fe 3+-chelated mon-poly(HEMA-MAH) nanospheres without significant loss of adsorption capacity. © The Korean Society for Biotechnology and Bioengineering and Springer 2011

Novel magnetic nanoparticles for the hydrolysis of starch with Bacillus licheniformis ?-amylase

Novel magnetic nanoparticles with an average size of 350-400 nm with N-methacryloyl-(L)-phenylalanine (MAPA) as a hydrophobic monomer were prepared by the surfactant-free emulsion polymerization of 2-hydroxyethyl methacrylate, MAPA, and magnetite in an aqueous dispersion medium. MAPA was synthesized from methacryloyl chloride and L-phenylalanine methyl ester. The specific surface area of the nonporous magnetic nanoparticles was found to be 580 m 2/g. Magnetic poly[2-hydroxyethyl methacrylate-N-methacryloyl-(L)- phenylalanine] nanoparticles were characterized by Fourier transform infrared spectroscopy, electron spin resonance, atomic force microscopy, and transmission electron microscopy. Elemental analysis of MAPA for nitrogen was estimated as 4.3 × 10-3 mmol/g of nanoparticles. Then, magnetic nano-poly[2-hydroxyethyl methacrylate-N-methacryloyl-(L)-phenylalanine] nanoparticles were used in the adsorption of Bacillus licheniformis ?-amylase in a batch system. With an optimized adsorption protocol, a very high loading of 705 mg of enzyme/g nanoparticles was obtained. The adsorption phenomena appeared to follow a typical Langmuir isotherm. The inverse of enzyme affinity for free amylase (181.82 mg/mL) was higher than that for immobilized enzyme (81.97 mg/mL). Storage stability was found to increase with adsorption. It was observed that the enzyme could be repeatedly adsorbed and desorbed without a significant loss in the adsorption amount or enzyme activity. © 2011 Wiley Periodicals, Inc

Dye incorporated nanopolymers and their application to leather wastewater: A study of removal of Cr(III) ions

In this presented work, Alkali Blue 6B-attached poly(2-hydroxyethyl methacrylate) nanopolymers (nano-PHEMA-AB) were synthesized as an adsorbent for the removal of the heavy metal Cr(III) from leather wastewater. For this purpose, first PHEMA nanopolymers were prepared by surfactant free emulsion polymerization. Alkali Blue 6B was then covalently attached to the PHEMA nanopolymers. Characterization of the nano-PHEMA-ABs was carried out by elemental analysis, SEM, FT-IR and Zeta Size analysis. The specific surface area of nano-PHEMA-AB was calculated to be 1131.2m2/g. The optimum adsorption conditions (i.e. adsorption capacity, medium pH, adsorption rate) were studied and reusability of nano-PHEMA-AB was also determined. The maximum Cr(III) adsorption capacity of nano-PHEMA-AB was found to be 4755.9mg/g at pH3.8. Additionally synthesized nano-PHEMA-AB were used for the removal of Cr(III) ions from chrome tanning wastewater and Cr(III) removal capacity of the nanopolymer was found to be 2724.2mg/g at pH3.9. According to the results, dye incorporated PHEMA nanopolymers can be used as an effective, re-usable remover of Cr(III) from leather wastewater due to their large surface area and high adsorption capacity. © 2016, Society of Leather Technologists and Chemists. All rights reserved.114M425This study was financially supported by the Scientific and Technological Research Council of Turkey (Project Number: 114M425). -