Abstract
Invertase is immobilized using an inorganic solid support, Molecular sieve 4A, via the metal link method. Bound enzyme showed maximum activity at pH 4.8 which was similar to that of soluble enzyme. Protein to solid support ratio was very critical for the retention of active invertase as loading beyond 18-20mg protein/g MS significantly decreased bound invertase activity. Km for the soluble and immobilized enzyme were found to be 20mM and 50mM respectively. Bound enzyme retained 90% original activity after 45 days at room temperature. Half-life for the continuous conversion of sucrose using MS-bound invertase was calculated to be 26 days. Used MS could be regenerated using perchloric acid. Regenerated MS did not require titanium activation and could retain 90% of the enzyme activity as compared to the control. Ammonium sulphate treatment was not effective in the regeneration of MS, indicating the enzyme is bound to MS by covalent linkage.
