초록
The production of succinic acid was studied with entrapped and adsorbed Actinobacillus succinogenes. The adsorption of fermentation products (organic acids in the concentration range of 1-20g/L) on different supports was evaluated. It was found that succinic acid was adsorbed in small quantities on diatomite and zeolite (12.6mg/g support). The highest production of succinic acid was achieved with A. succinogenes entrapped in agar beads. Batch fermentations with immobilized cells were carried out with glucose concentrations ranging from 20 to 80g/L. Succinic acid (43.4g/L) was obtained from 78.3g/L glucose, and a high productivity (2.83g/Lh) was obtained with a glucose concentration of 37.6g/L. For repeated batch fermentations (5 cycles in 72h) with immobilized cells in agar, the total glucose consumed was 147.55g/L, while the production of succinic acid was 107g/L. Immobilized cells reduced significantly the fermentation time, yield, productivity and final concentration of succinic acid.