Studies on Kinetics and Thermostability of a Novel Acid Invertase from Fusarium solani

• Published in: Journal of agricultural and food chemistry Vol. 54; no. 13; pp. 4617 - 4623
• Main Authors: Bhatti, Haq Nawaz, Asgher, Muhammad, Abbas, A, Nawaz, Rakhshanda, Sheikh, Munir A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 28.06.2006
• Subjects: Ammonium Sulfate; beta-fructofuranosidase; beta-Fructofuranosidase - isolation & purification; beta-Fructofuranosidase - metabolism; Biological and medical sciences; Chemical Precipitation; enthalpy; entropy; enzyme activity; enzyme kinetics; Enzyme Stability; Food industries; Fundamental and applied biological sciences. Psychology; Fusarium - enzymology; Fusarium solani; heat stability; Hot Temperature; Hydrogen-Ion Concentration; Kinetics; Molecular Weight; temperature; Thermodynamics; Purification; Enzyme; β-Fructofuranosidase; thermodynamics; β-D-Fructofuranosidase; Thermal stability; Fungi; Acids; Glycosidases; Hydrolases; Fusarium solani; Fungi Imperfecti; Kinetics; O-Glycosidases; Thallophyta
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf053194g

The present investigation deals with purification and thermal characterization of an acid invertase produced by Fusarium solani in submerged culture. The maximum enzyme activity (9.90 U mL-1) was achieved after 96 h of cultivation at pH 5.0 and 30 °C in a basal medium containing molasses (2%) as the carbon and energy source supplemented with 1% peptone. Invertase was purified by ammonium sulfate fractionation and column chromatography on DEAE-cellulose and Sephadex G-200. The purified enzyme was proven to be homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The molecular mass of the enzyme was 65 kDa. The optimum pH and temperature for activity were 2.6 and 50 °C, respectively. The K m value for sucrose was 3.57 mM with an activation energy of 4.056 kJ mol-1. Enthalpies of activation (ΔH*) were decreased while entropies (ΔS*) of activation increased at higher temperatures. The effects of α-chymotrypsin and 4 M urea were tetraphasic with periodic gain and loss of enzyme activity. A possible explanation for the thermal inactivation of invertase at higher temperatures is also discussed. Keywords: β-d-Fructofuranosidase; Fusarium solani; purification; thermodynamics; thermal stability