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Production, purification and thermal characterisation of invertase from a newly isolated Fusarium sp. under solid‐state fermentation
Author(s) -
Shaheen Iram,
Bhatti Haq Nawaz,
Ashraf Tallat
Publication year - 2008
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2007.01581.x
Subject(s) - invertase , solid state fermentation , sephadex , chemistry , size exclusion chromatography , fermentation , chromatography , ammonium , enzyme assay , specific activity , enzyme , ion chromatography , nitrogen , biochemistry , organic chemistry
Summary Production of invertase employing a newly isolated Fusarium sp. under solid‐state fermentation was optimised. Different process parameters were optimised. The maximum enzyme activity under optimum conditions was 47.23 ± 2.12 U gds −1 with nitrogen additives. The enzyme was purified by ammonium sulphate precipitation, diethylaminoethyl cellulose ion‐exchange chromatography and Sephadex gel filtration. This protocol gave 20.25‐fold purification and 5.53% recovery. The optimum pH and temperature for activity were 5.0 and 50 °C. The K m and V max values for the enzyme were 8.33 m m and 21.48 μmol min −1 , respectively. A detailed kinetic study of thermal inactivation has been carried out. Enthalpy of activation (Δ H *) decreased when entropy (Δ S *) of activation increased at higher temperatures. Moreover, free energy of denaturation (Δ G *) increased at higher temperature making the enzyme thermally stable. A possible explanation for the thermal inactivation of invertase at higher temperatures is also discussed.