Optimization and scale up of itaconic acid production from potato starch waste in stirred tank bioreactor

Present study used Aspergillus terreus strain C1 isolated from mangrove soil for itaconic acid (IA) production from potato starch waste. Fermentation parameters were optimized by classical one factor approach and statistical experimental designs, such as Plackett-Burman and response surface designs. Anionic deionization of potato waste was found to be a very effective, economic, and easy way of improving IA production. The increase in IA production by deionization was found to correlate with removal of phosphate. In our knowledge, this is the first report on application of deionization of potato waste to enhance IA production. Other parameters like inoculum development conditions, pH, presence of peptone and certain salts in the medium also significantly affected IA production. IA production by strain C1 increased 143-fold during optimization when compared with the starting condition. The optimized IA level (35.75 g/L) was very close to the maximum production predicted by RSM (38.88 g/L). Bench scale production of IA was further optimized in 3-L stirred tank reactor by varying parameters like agitation and aeration rate. The maximum IA production of 29.69 g/L was obtained under the agitation speed of 200 rpm and aeration rate of 0.25 vvm. To the best of our knowledge, it is the first report on IA production from potato starch waste at bioreactor level. (c) 2019 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2774, 2019.