OPIMIZATION OF ITACONIC ACID FERMENTATION IN A SHAKEN FLASK AND PRODUCTION SCALING UP

Abstract

The different fermentation condition of itaconic acid production by Aspergillus terreus was studied. The fermentation was divided into two phases: cell growth phase and itaconic acid production phase. In cell growth phase, the organic medium is preferred for cell growth. The highest cell biomass was reached after 3 days with glucose - yeast extract medium. Whereas itaconic production phase, the inorganic medium was lead to the maximum itaconic acid concentration. In flasks shaken, it was found that there is 21.98 g/L of itaconic acid were released at 30°C, pH 2 and 200 rpm for 7 days. Moreover, the morphology of A.terreus that suit itaconic acid production is a small pellet was found in this condition. When the production was scaled up, there is not successfully for itaconic acid production. In 5 L of stirred tank reactor, there is a little bit of itaconic acid were reached. Despite agitation speed were increased, itaconic acid production is not increase. However, glucose was consumed for cell growth and generating ATP for survival not itaconic acid formation. In addition, a small pellet which suit for itaconic acid production was not found in 5L bioreactor. Immobilization technique including adsorption and entrapment were also tested for itaconic acid production but with a poor result. It cannot compete with the production from a small scale like flasks shaken. However, the performance of cell immobilized might be depending on a nature of cell, medium composition and other factors.