Abstract

IMMOBILIZATION ON CHITIN AND POLYETHYLENE OF INVERTASE OBTAINED FROM YEAST GROWN IN MOLASSES BY FED-BATCH PROCESS

Michele Vitolo*

ABSTRACT

Saccharomyces cerevisiae is largely used in industry and in biochemical studies. The main product extracted from this yeast is invertase, which has many applications, for instance in syrup production in either soluble or immobilized form. This study dealt with invertase production from S. cerevisiae grown in blackstrap molasses by fed-batch fermentation. Fermentation parameters as specific rate of cell growth (), substrate consumption, generation time, and invertase activity of intact yeast cells were determined. The invertase present in cells obtained by exponential fed-batch culture was extracted and purified. The purified invertase was immobilized on chitin (adsorption plus cross-binding with glutaraldehyde) and polyethylene (covalent binding). The kinetic (KM and Vmax) and thermodynamic (Ea, G, H, and S) constants of all forms of invertase were calculated.

Keywords: Invertase, chitin, polyethylene, yeast, molasses, fed-batch.