Topic
Immobilized enzyme
About: Immobilized enzyme is a research topic. Over the lifetime, 15282 publications have been published within this topic receiving 401860 citations.
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TL;DR: An enzymatic method for removal of phenols from industrial wastewater was investigated and immobilized tyrosinase, immobilized by using amino groups in the enzyme on cation exchange resins, can be used repeatedly.
Abstract: An enzymatic method for removal of phenols from industrial wastewater was investigated. Phenols in an aqueous solution were removed after treatment with mushroom tyrosinase. The reduction order of substituted phenols is catechol > p-cresol > p-chlorophenol > phenol > p-methoxyphenol. In the treatment of tyrosinase alone, no precipitate was formed but a color change from colorless to dark-brown was observed. The colored products were removed by chitin and chitosan which are available abundantly as shellfish waste. In addition, the reduction rate of phenols was observed to be accelerated in the presence of chitosan. Tyrosinase, immobilized by using amino groups in the enzyme on cation exchange resins, can be used repeatedly. By treatment with immobilized tyrosinase, 100% of phenol was removed after 2 h, and the activity was reduced very little even after 10 repeat treatments.
117 citations
TL;DR: The newly developed immobilization method is simple, yet effective and can be used for the immobilization of other enzymes.
117 citations
TL;DR: In this paper, an enzyme with broad substrate specificity for the phenolic substrates was employed as a biorecognition element in order to develop a biosensor for total content evaluation of phenolic secondary metabolites from two “in vitro” cultivated plants: Salvia officinalis and Mentha piperita.
Abstract: Laccase from Trametes versicolor, an enzyme with broad substrate specificity for the phenolic substrates was employed as a biorecognition element in order to develop a biosensor for total content evaluation of phenolic secondary metabolites from two “in vitro” cultivated plants: Salvia officinalis and Mentha piperita. The enzyme immobilization was carried out by entrapment into the nanocomposite film during electrodeposition process from multiwall carbon nanotubes (MWCNT)–chitosan (CS) solution containing 25 U/mL laccase. Optimum conditions for MWCNT–CS film deposition (2 mg MWCNT/mL chitosan 1% solution prepared in 1% acetic acid) on gold support using a −1.5 V vs. Ag/AgCl controlled potential V for 5 min were established taking into consideration the layer capacity value. FTIR studies were performed to obtain information about the secondary structure of enzyme entrapped into the MWCNT–CS nanocomposite film. Calibration of the laccase biosensor was performed on four phenolic acids (caffeic acid, chlorogenic acid, gallic acids and rosmarinic acid) as substrates at −0.2 V vs. Ag/AgCl reference electrode. The developed biosensor was sensitive to micromolar concentration of the tested polyphenols. The performance characteristics of the biosensor for rosmarinic acid were: limit of detection 2.33 × 10−7 mol L−1, response linear range 9.1 × 10−7–1.21 × 10−5 mol L−1 and sensitivity 846 μA/mmol. The obtained values of the Kmapp for all tested substrates proved that nanocomposite film provides a proper environment for enzyme immobilization, preserving enzyme catalytic specificity. The functionality of the developed biosensor was tested to evaluate the total polyphenolic content from real samples (S. officinalis and M. piperita extracts), results being expressed in equivalent rosmarinic acid.
117 citations
TL;DR: In this article, the use of β-glucosidase for synthesizing octyl-β-glocoside was studied and the best results were obtained using a high initial water activity which was decreased during the course of the reaction.
117 citations
TL;DR: A novel technique to directly immobilize the in-house crude enzyme extracts from P. ostreatus onto the functionalized TiO 2 nanoparticle surface and the resultant biocatalytic nanoparticles had comparable performance to the immobilized purified commercial enzymes.
117 citations