Data/hora: 24/09/2024 18:15:30

Biblioteca(s): 	Embrapa Agroindústria de Alimentos.	
Data corrente: 	25/02/2010	
Data da última atualização: 	26/02/2010	
Autoria: 	GREINER, R.; SILVA, L. G. da; COURI, S.	
Afiliação: 	RALF GREINER, Federal Research Institute of Nutrition and Food-Germany; LUCINEIA GOMES DA SILVA, CEFET; SONIA COURI, CTAA.	
Título: 	Purification and characterisation of an extracellular phytase from Aspergillus niger 11T53A9.	
Ano de publicação: 	2009	
Fonte/Imprenta: 	Brazilian Journal of Microbiology, São Paulo, v. 40, n. 4, p. 795-807, oct./dec. 2009.	
DOI: 	10.1590/S1517-83822009000400010	
Idioma: 	Inglês	
Conteúdo: 	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 KM = 54 µmol l-1 and kcat = 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.	
Palavras-Chave: 	Fitase.	
Thesagro: 	Aspergillus Niger.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
URL: 	http://www.scielo.br/pdf/bjm/v40n4/v40n4a10.pdf	
Registro original: 	Embrapa Agroindústria de Alimentos (CTAA)	
Exemplares: 	CTAA - (10149-1) - UPC - SP - PP - 2009/118 -  - 2010.00029 - DIS