The production of invertase from the by-product of baker's yeast (Saccharomyces cerevisiae) factory

In the present study, the production possibility of invertase enzyme from sieve residue yeast, by-product of baker's yeast (Saccharomyces cerevisiae) factory, was investigated. Crude enzyme extracts obtained from sieve residue yeast (i) spray dried, (ii) lyophilized and (iii) collected in aqueous form were compared with (iv) industrial invertase enzyme sample in terms of enzymatic activity. Every sample was analyzed for enzymatic activity at constant temperature (40°C) and at different pH values between 4 and 7 in order to find out the optimum pH value for highest enzymatic activity. Then, the pH value was kept constant at optimum value and the enzymatic activity was determined at different temperature levels between 30-70°C.Optimum pH value was determined as 4,5 for all samples and the enzymatic activity was found as 3,30, 2,90, 2,91 and 1,73 u/ml for industrial invertase enzyme, spray dried, lyophilized and aqueous extract, respectively. The analysis at optimum pH of 4,5 and at different temperatures showed that the highest enzymatic activity was screened at 40°C for all samples. Additionally, there was a significant loss of enzymatic activity at 60-65°C for all samples.Finally, the study showed that sieve residue yeast has a usage potential in invertase production. While this by-product is sold at low price for animal feeding purposes, advanced purification techniques can be used to create added value in this sector. Keywords: Sieve residue yeast, invertase, activity.