Optimization of culture conditions for baker's yeast cell mass production - a plreliminary study

Abstract

The aim of this study was to find out suitable culture conditions to improve the cell mass production of Saccharomyces cerevisiae. S. cerevisiae was grown in a medium (30°C, pH 5.0) with sucrose (Table sugar) from 10 to 50gL~', along with (gL'1) yeast extract (2.5), bacteriological peptone (1.15), (NH4)HPO4 (0.25) and MgSOf 7H2O (0.025). Highest cell mass of 4.43gL'' was obtained in the medium with 5OgL'1 of sucrose. When the oxygen supply and diffusion were improved by either, mixing in a shaker (lOOrpm), by an impeller (lOOrpm) or aeration (lOObubbles/min), highest cell mass (4.52gL'') was obtained with aeration. Increase in aeration rate to 200bubbles/min increased the yeast cell mass to 5.41gL~'. For volumetric scaling up, medium to flask volume ratio was maintained as 1:2, in 1, 2, 3, and 5L flasks, and the highest cell mass (5.53gL~!) was produced in 2L flask. By optimizing the culture conditions the yeast cell mass production was increased by 1.25 times.