Data/hora: 06/06/2024 09:46:31

Provedor de dados: 	69	
País: 	Chile	
Título: 	Preparation and characterization of &amp;#954;-carrageenase immobilized onto magnetic iron oxide nanoparticles	
Autores: 	Xiao,Anfeng; Xu,Caiyun; Lin,Yan; Ni,Hui; Zhu,Yanbing; Cai,Huinong.	
Data: 	2016-01-01	
Ano: 	2016	
Palavras-chave: 	Carrageenase; Characterization; Immobilization; Nanoparticles.	
Resumo: 	Background Carboxyl-functionalized magnetic nanoparticles were synthesized via chemical co-precipitation method and modified with oleic acid which was oxidized by potassium permanganate, and &amp;#954;-carrageenase from Pseudoalteromonas sp. ASY5 was subsequently immobilized onto them. The immobilization conditions were further optimized, and the characterizations of the immobilized &amp;#954;-carrageenase were investigated. Results The &amp;#954;-carrageenase was immobilized onto magnetic iron oxide nanoparticles, and the bonding was verified by Fourier transform infrared spectroscopy. The optimal conditions for &amp;#954;-carrageenase immobilization were 2.5% (w/v) glutaraldehyde, 13.9 U &amp;#954;-carrageenase for 20 mg of magnetic nanoparticles, a 2-h cross-linking time, and a 2-h immobilization time at 25°C. Under these conditions, the activity of the immobilized enzyme and the enzyme recovery rate were 326.0 U · g- 1 carriers and 46.9%, respectively. The properties of the immobilized &amp;#954;-carrageenase were compared with those of the free enzyme. The optimum temperatures of the free and immobilized &amp;#954;-carrageenase were 60 and 55°C, respectively, and the optimum pH of &amp;#954;-carrageenase did not change before and after immobilization (pH 7.5). After immobilization, &amp;#954;-carrageenase exhibited lower thermal stability and improved pH stability, as well as better storage stability. The immobilized &amp;#954;-carrageenase maintained 43.5% of the original activity after being used 4 times. The kinetic constant value (Km) of &amp;#954;-carrageenase indicates that the immobilized enzyme had a lower binding affinity for the substrate. Conclusions Under optimal conditions, the activity of the immobilized enzyme and enzyme recovery rate were 326.0 U · g- 1·&amp;#954;-carrageenase-CMNPs and 46.9%, respectively. The thermal, pH, and storage stabilities of &amp;#954;-carrageenase-CMNPs were relatively higher than those of free &amp;#954;-carrageenase.	
Tipo: 	Journal article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000100001	
Editor: 	Pontificia Universidad Católica de Valparaíso	
Formato: 	text/html	
Fonte: 	Electronic Journal of Biotechnology  v.19 n.1 2016