Data/hora: 05/06/2024 05:21:01

Provedor de dados: 	58	
País: 	Brazil	
Título: 	Purification and characterisation of an extracellular phytase from Aspergillus niger 11T53A9	
Autores: 	Greiner,Ralf; Silva,Lucineia Gomes da; Couri,Sonia.	
Data: 	2009-12-01	
Ano: 	2009	
Palavras-chave: 	Aspergillus niger; Phytate-degrading enzyme; Phytate; Phytase.	
Resumo: 	An extracellular phytase from Aspergillus niger 11T53A9 was purified about 51-fold to apparent homogeneity with a recovery of 20.3% referred to the phytase activity in the crude extract. Purification was achieved by ammonium sulphate precipitation, ion chromataography and gel filtration. The purified enzyme behaved as a monomeric protein with a molecular mass of about 85 kDa and exhibited maximal phytate-degrading activity at pH 5.0. Optimum temperature for the degradation of phytate was 55°C. The kinetic parameters for the hydrolysis of sodium phytate were determined to be K M = 54 µmol l-1 and k cat = 190 sec-1 at pH 5.0 and 37°C. The purified enzyme was rather specific for phytate dephosphorylation. It was shown that the phytase preferably dephosphorylates myo-inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via D-Ins(1,2,4,5,6)P5, D-Ins(1,2,5,6)P4, D-Ins(1,2,6)P3, D-Ins(1,2)P2 to finally Ins(2)P.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000400010	
Editor: 	Sociedade Brasileira de Microbiologia	
Relação: 	10.1590/S1517-83822009000400010	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Microbiology  v.40 n.4 2009	
Fonte: 	info:eu-repo/semantics/openAccess