Optimization of simultaneous saccharification and fermentation process conditions for the production of succinic acid from oil palm empty fruit bunches

Abstract

Succinic acid has been characterized as a commodity chemical and attractive compound as it has wide applications as a key building block for various high value-added chemicals. In this study, simultaneous saccharification and fermentation (SSF) process conditions for the production of succinic acid from oil palm empty fruit bunches by Actinobacillus succinogenes (A. succinogenes) were statistically optimized for the first time. Factors that influence succinic acid production, such as temperature, pH, and cellulase loading, were screened using full factorial design. The experimental conditions of SSF for succinic acid production were optimized by varying the temperature (36 °C, 38 °C, and 40 °C), pH (5, 6.5, and 8), and cellulase loading (10, 25, and 40 FPU/g). The results revealed that these three factors had significant effects on succinic acid production. Response surface methodology (RSM) was used to optimize the operating conditions of SSF to obtain a high yield of succinic acid. The optimum conditions for SSF occurred at 36 °C, pH 5, and cellulase loading of 39.7 FPU/g, with succinic acid production of 42.9 g/L and a conversion yield of 0.61 g/g. The validation results showed that the experimental values of succinic acid were in agreement to RSM prediction with a small percentage error.