Purification and characterization of polygalacturonase produced by thermophilic Thermoascus aurantiacus CBMAI-756 in submerged fermentation
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Data
2007-04-01
Autores
Martins, Eduardo Silva
Silva, Denis
Leite, Rodrigo S. R.
Gomes, Eleni
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Editor
Springer
Resumo
An extracellular polygalacturonase was isolated from 5-day culture filtrates of Thermoascus aurantiacus CBMAI-756 and purified by gel filtration and ion-exchange chromatography. The enzyme was maximally active at pH 5.5 and 60-65 degrees C. The apparent K (m) with citrus pectin was 1.46 mg/ml and the V (max) was 2433.3 mu mol/min/mg. The apparent molecular weight of the enzyme was 30 kDa. The enzyme was 100% stable at 50 degrees C for 1 h and showed a half-life of 10 min at 60 degrees C. Polygalacturonase was stable at pH 5.0-5.5 and maintained 33% of initial activity at pH 9.0. Metal ions, such as Zn+2, Mn+2, and Hg+2, inhibited 50, 75 and 100% of enzyme activity. The purified polygalacturonase was shown to be an endo/exo-enzyme, releasing mono, di and tri-galacturonic acids within 10 min of hydrolysis.
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Palavras-chave
polygalacturonase, purification, Thermoascus aurantiacus
Como citar
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology. Dordrecht: Springer, v. 91, n. 3, p. 291-299, 2007.