Optimization of parameters growth conditions of yeast biomass during single cell protein production by using simplex method

The aim of this study is to find optima of operating conditions, such as temperature and pH, during yeast's cultivation by using simplex method. The idea behind applying simplex method was the interaction between these two variables. Yeast (Saccaromyces cerevisiae) was cultivated at different pH and temperatures ranges in complex medium of limiting glucose. Other parameters such as air flow rate and stirring speed were held constant as they have their own effect. Air flow rate was held constant at 1.5 L/min. while stirring speed was 600 rpm within bioreactor of 750 mL working volume. Saccaromyces cerevisiae was cultivated in a batch mode. Optima of temperature of (27.7 C-0) and pH of (4.0) was obtained within only 28 runs by using simplex method. The range of pH was (3.0-7.0) and the range of temperature was (26.4-32 C-0) with an interval increment of 0.2 for both variables. By applying fully factorial design one needs to run as much 540 experiments within a bioreactor in order to cover the range of pH and temperature mentioned above. These results showed the effective of simplex method in optimization of parameters. Also the study shows a big economic aspect by reducing number of required experiments to obtain optima of pH and temperature. This means reducing the cost of energy, medium and time as well.