Purification and kinetic properties of a novel β-amylase from Penicillum citrinum AS-9 | ||||
Egyptian Journal of Chemistry | ||||
Article 55, Volume 65, Issue 3, March 2022, Page 581-587 PDF (334.82 K) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/ejchem.2021.95187.4510 | ||||
View on SCiNiTO | ||||
Authors | ||||
abdelmohsen Saber 1; Milada Abdel-Malikb2; Ahmed I Eldiwany 3; Ahmed Afifib4 | ||||
1Chemistry of Natural and Microbial Products Dept., Pharmaceutical and Drug Industries Research Div.National Research Centre, Dokki, Giza, Egypt P.O. Box: 12622 | ||||
2Dept. of Biological and Geological Sciences, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt | ||||
3National Resesrch Centre | ||||
4Dept. of Biological and Geological Sciences, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt. | ||||
Abstract | ||||
β-amylase-rich preparation produced by the soil fungal strain Penicillium citrinum AS-9 was completely purified within the succeeding steps; ultrafiltration, acetone fractionation and gel filtration on Sephadex G-150 column. Acetone fractionation recovered the highest β-amylase activity and the 85% acetone fraction exhibited 3.5-fold activity that of the crude enzyme. The column affected 8.6-fold purification for β-amylase, which produced maltose as the major product of starch hydrolysis. The pure enzyme showed a Km value of 17.5 mM and Vmax of 17.5 Umg-1 protein, applying Woolf plot and exhibited its maximum velocity at pH 7.1 and 50°C. In absence of substrate, thermal treatments of the enzyme solution at pH 5.2 and 5.5 had the most adverse effects on the enzyme activity. CaCl2 (1mM) activated the enzyme, while each of Ca2+, Fe3+, cysteine, cystine, I2 and p-chloromercuribenzoate (PCMB) had different inhibitory effects. Maltose as the enzyme product at final concentration of 80 mM strongly inhibited the enzyme. | ||||
Keywords | ||||
Starch; β-amylase-rich preparation; Penicillium citrinum AS-9; Chromatographic purification; kinetic properties | ||||
Statistics Article View: 178 PDF Download: 130 |
||||