Statistical Optimization of Culture Media and Conditions for Maximize Production of Mannan by Saccharomyces Cerevisiae Using Response Surface Methodology

Abstract

Aim: In view of the increase in Saccharomyces cerevisiae mannan content, the culture medium and condition for S. cerevisiae were optimized in this study. Study Design: The mathematical model was established by the quadratic rotary combination design via Response Surface Methodology to evaluate the effect of culture condition and media on mannan content in the yeast cell wall. Methodology: The influence of culture medium ingredients such as carbon source (FOS, in the range of 2 – 9 g/100ml) and nitrogen source (mixture of peptone and yeast extract, in the range of 1-5g/100ml), and enzyme activator (glycerol, in the range of 1-4g/100ml) on mannan production were evaluated using Response surface methodology. Also The influence of original pH (in the range of 4-7), inoculums size (in the range of 2-4%) and temperature (in the range of 26-32ºC), on mannan production was evaluated and confirmed by quadratic design. Results: The optimized concentrations of culture medium were determined as follows: 8.99 g/100mL, FOS; 4.25 g/100 ml, mixture of bacto peptone and yeast extract; and 3 g/100mL, glycerol. The order of effect was carbon source› nitrogen source› enzyme activator. Also The order of effect of original pH, inoculums size, and temperature, on mannan production was as follows: temperature > initial pH > inoculation size. The optimized culture condition was pH, 6.62; inoculums size, 4 ml; temperature, 32ºC. The maximum mannan production increased to 94.912 ±9.1 mg/100 ml at the optimum culture condition. Conclusion: It was evident that the mannan production was affected significantly by culture medium and condition optimization (p < 0.01).