| Registro completo |
| Provedor de dados: |
BJM
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| País: |
Brazil
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| Título: |
Isolation of a thermostable acid phytase from Aspergillus niger UFV-1 with strong proteolysis resistance
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| Autores: |
Monteiro,Paulo S.
Guimarães,Valéria M.
Melo,Ricardo R. de
Rezende,Sebastião T. de
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| Data: |
2015-03-01
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| Ano: |
2015
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| Palavras-chave: |
Phosphatase
Phytic acid
Dephosphorylation
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| Resumo: |
An Aspergillus niger UFV-1 phytase was characterized and made available for industrial application. The enzyme was purified via ultrafiltration followed by acid precipitation, ion exchange and gel filtration chromatography. This protein exhibited a molecular mass of 161 kDa in gel filtration and 81 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), indicating that it may be a dimer. It presented an optimum temperature of 60 °C and optimum pH of 2.0. The KM for sodium phytate hydrolysis was 30.9 mM, while the kcat and kcat/KM were 1.46 ×105 s−1 and 4.7 × 106s−1.M−1, respectively. The purified phytase exhibited broad specificity on a range of phosphorylated compounds, presenting activity on sodium phytate, p-NPP, 2- naphthylphosphate, 1- naphthylphosphate, ATP, phenyl-phosphate, glucose-6-phosphate, calcium phytate and other substrates. Enzymatic activity was slightly inhibited by Mg2+, Cd2+, K+ and Ca2+, and it was drastically inhibited by F−. The enzyme displayed high thermostability, retaining more than 90% activity at 60 °C during 120 h and displayed a t1/2 of 94.5 h and 6.2 h at 70 °C and 80 °C, respectively. The enzyme demonstrated strong resistance toward pepsin and trypsin, and it retained more than 90% residual activity for both enzymes after 1 h treatment. Additionally, the enzyme efficiently hydrolyzed phytate in livestock feed, liberating 15.3 μmol phosphate/mL after 2.5 h of treatment.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000100251
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| Editor: |
Sociedade Brasileira de Microbiologia
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| Relação: |
10.1590/S1517-838220120037
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Microbiology v.46 n.1 2015
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| Direitos: |
info:eu-repo/semantics/openAccess
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