Data/hora: 02/06/2024 16:48:19

Biblioteca(s): | Embrapa Agroindústria de Alimentos.
Tipo da produção científica: | Artigo em Periódico Indexado
Circulação/Nível: | B - 1
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