Optimization studies on biosynthesis of citric acid by one-factor-at-a-time

Abstract

In the presented study, the significant operating variables regarding biosynthesis of citric acid process were assessed and their effects on the process yield were analysed. These variables, namely, initial sucrose concentration, methanol concentration, inoculum density, initial medium pH, spore age, stirrer speed, incubation period, fermentation temperature, particle size distribution, oxygen flow rate, and moisture content have significant influence on bioprocess of citric acid production. Plackett-Burman approach was used to determine the most significant variables, which predominantly influence the citric acid production process. Out of the eleven variables, initial sucrose concentration, initial medium pH, stirrer speed, incubation period, fermentation temperature, and oxygen flow rate were found to be significant. The effect of the significant variables on the yield of citric acid has been validated experimentally by one-factor-at-a-time empirical optimization technique. The optimum conditions have been determined. The effect of each variable on the yield of citric acid was analysed critically.