Back to Contents

FREE FULL TEXT PDF

SUBSTRATE-INDUCED REPRESSION OF INVERTASE SYNTHESIS BY SACCHAROMYCES CEREVISIAE IN SUBMERGED CULTURE

IKRAM-UL-HAQ, ^*KIRAN SHAFIQ AND SIKANDER ALI

Abstract: Invertase enzyme is used traditionally in the production of inverted sugars for industry, especially in the manufacture of candies and preserves, production of lactic acid and ethanol production from fermentation of cane sugar molasses. The present study deals with the substrate-induced changes in invertase formation by Saccharomyces cerevisiae KR₁₈. The maximal production of invertase during the course of study i.e. 5.63±0.9 U ml^-1, was achieved using initial sucrose concentration of 15.0 g l^-1 after 48 h of fermentation. The sugar consumption and mycelial dry weight were 9.65±1.3 and 2.62±0.3 mg ml^-1, respectively. Higher concentrations of sucrose in fermentation medium induce catabolite repression of yeast invertase. All the kinetic parameters i.e., product and growth yield coefficients (Yp/s, Yp/x and Yx/s), and specific rate constants, µ (h^-1) were highly significant.

Biotechnology Research Center, Department of Botany, Government College University, Lahore, Pakistan.
Corresponding Author: shafiq_kiran@hotmail.com