Polyacrylonitrile enzyme ultrafiltration membranes prepared by adsorption, cross-linking, and covalent binding

Ulbricht, Mathias; Papra, Alexander

doi:10.1016/s0141-0229(96)00085-3

Cited by 57 publications

(23 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The result indicates that the maximum reaction rate of urease immobilized membrane under dynamic conditions is enhanced which might be due to acceleration of mass transfer with continuous permeation of substrate through the membrane. Similar results have also been reported in the literature [43,44].…”

Section: Filtration Resultssupporting

confidence: 92%

Catalytic performances of chemically immobilized urease under static and dynamic conditions: A comparative study

Yürekli

Altınkaya

2011

Journal of Molecular Catalysis B: Enzymatic

View full text Add to dashboard Cite

a b s t r a c tImmobilized urease has been used for direct removal of urea from aqueous solution and as biological sensing material in the preparation of urea biosensors. The former application is carried out under dynamic condition using ultrafiltration membrane either in tubular form or in flat sheet, while the latter is used in static condition. In this study, the performance of chemically immobilized urease on poly(acrylonitrileco-sodium methallyl sulfonate) ultrafiltration membrane was determined under both static and dynamic conditions. Results reveal that the immobilization enhanced the thermal and storage stabilities of urease. The hydraulic permeability of urea solution was not influenced by the addition of enzyme layer. The maximum reaction rate measured under pressure in the ultrafiltration unit was found higher compared to the rate observed just under mixing without any pressure applied. The highest urea conversion was found at the lowest transmembrane pressure and the urea concentration in the feed solution. The catalytic activity of the membrane was completely preserved at the end of 450 min of filtration.

show abstract

Section: Filtration Resultssupporting

confidence: 92%

Catalytic performances of chemically immobilized urease under static and dynamic conditions: A comparative study

Yürekli

Altınkaya

2011

Journal of Molecular Catalysis B: Enzymatic

View full text Add to dashboard Cite

show abstract

“…4 by the method of Lineweaver-Burk, show that the hydrogel-supported invertase preparations obey Michaelis-Menten kinetics. The Michaelis-Menten constant K m with the small substrate maltose was 3.5 mmol -1 L for free and 3.2 mmol -1 L for covalently bound enzyme, whereas V max values with maltose and starch dropped to 32% and 22%, respectively, for the immobilized versus free enzyme 31) . In this study, the values for the Michaelis-Menten parameters of free and adsorbed invertase, as calculated from the results shown in Fig.…”

Section: Kinetic Parametersmentioning

confidence: 92%

The effect of external stimuli on the invertase adsorption capacity of poly(N-vinyl-2-pyrrolidone-co-itaconic acid) hydrogels

Tümtürk

aykara²,

Kantoğlu

et al. 1999

Angew. Makromol. Chem.

View full text Add to dashboard Cite

Polyelectrolyte Poly(N‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) hydrogels (P(VP/IA)) with varying compositions were prepared from ternary VP/IA/water mixtures. The effect of external stimuli such as pH of the solution, temperature, substrate concentration of solution, and storage stability on the invertase adsorption capacity of P(VP/IA) hydrogels was investigated. The adsorption capacity of the hydrogels was found to increase from 4.4 to 18.4 mg invertase/g dry gel with increasing amount of IA in the gel system, while P(VP) gel adsorbed only 3.1 mg invertase/g dry gel. Kinetic parameters were calculated as Michaelis‐Menten constant Km = 20.6 mmol L–1 and maximum velocity Vmax = 6.44×10–5 mol dm–3 min–1 for free enzyme and in the range of Km = 26.4–41.1 mmol L–1 and Vmax = 6.35·10–5–6.66·10–5 mol dm–3 min–1, depending on the amount of IA in the hydrogel. Enzyme activities were found to increase from 59.0% to 72.0% with increasing amount of IA in the gel system and retained their activities for one month storage. The enzyme activities, after storage for one month at 4°C, were found to be 21.0% and 59.0–74.0% of the initial activity values for free and adsorbed enzyme, respectively. The optimal pH values for free and adsorbed enzymes were determined as 4.56 and 5.00, respectively. The optimum temperature for free and adsorbed enzymes was 55°C. Adsorption studies have shown that not only the gel composition but also the stimuli, temperature and pH of the solution play an important role on the invertase adsorption capacity of poly(VP/IA) hydrogels.

show abstract

“…By adsorption [32,59] By covering [32] Aqueous Dissolved [26] Immobilised By surfactant coating [29] adsorption ef®ciency tests, the hydrodynamic conditions have to be taken into consideration besides the enzyme concentration [57]. Presumably, the new methods making more stable the adsorptive bond between the membrane and hydrophilic enzymes, developed recently by Kubota et al for other proteins [58] will be useful in the future for enzyme immobilisation.…”

Section: Biocatalyst Confinement In Enzyme Membrane Reactorsmentioning

confidence: 99%

Technical aspects of separation and simultaneous enzymatic reaction in multiphase enzyme membrane reactors

Sisak

Nagy

Burfeind

et al. 2000

Bioprocess Engineering

View full text Add to dashboard Cite

The technical aspects of the membrane extraction of a compound either from aqueous phase into apolar organic solvent phase or from the apolar phase to the aqueous one and the enzymatic conversion of the solute in a multiphase enzyme membrane reactor are considered. The application possibilities, the selection aspects of membrane material as well as the solvent phase, the water content and its control, the method of the enzyme immobilisation and the operation of the extraction/reaction system are discussed.

show abstract

Polyacrylonitrile enzyme ultrafiltration membranes prepared by adsorption, cross-linking, and covalent binding

Cited by 57 publications

References 17 publications

Catalytic performances of chemically immobilized urease under static and dynamic conditions: A comparative study

Catalytic performances of chemically immobilized urease under static and dynamic conditions: A comparative study

The effect of external stimuli on the invertase adsorption capacity of poly(N-vinyl-2-pyrrolidone-co-itaconic acid) hydrogels

Technical aspects of separation and simultaneous enzymatic reaction in multiphase enzyme membrane reactors

Contact Info

Product

Resources

About