Cheng K.-C.Demirci A.Catchmark J.M.KUAN-CHEN CHENG2019-07-112019-07-11201102608774https://scholars.lib.ntu.edu.tw/handle/123456789/413461Pullulan fermentations by Aureobasidium pullulans with various initial ammonium ion concentrations were evaluated in a 2-L bioreactor. The results demonstrated that A. pullulans produced highest pullulan (23.1 g/L) when the initial ammonium sulfate was 7 at 5 g/L. The purity of produced pullulan was 94.6%. Seven gram per liter of ammonium sulfate produced more biomass due to the higher level of nitrogen source, but the pullulan-degrading enzyme activity was detected after the depletion of sucrose, which reduced pullulan concentration. From the results of fed-batch fermentation, addition of 10 g/L of sucrose suppressed A. pullulans from producing pullulan-degrading enzyme. Additionally, the modified-Gompertz equation demonstrated its generality to fit all pullulan production, biomass production, and sucrose consumption curves at three ammonium sulfate levels. After incorporating the degrading factor, a re-modified-Gompertz equation was obtained that can adequately describe the decrease of pullulan at the late fermentation stage. ? 2010 Elsevier Ltd. All rights reserved.Aureobasidium pullulansFermentationGompertz equationModelingPullulanPullulanase[SDGs]SDG6journal article10.1016/j.jfoodeng.2010.10.0042-s2.0-78649474518https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649474518&doi=10.1016%2fj.jfoodeng.2010.10.004&partnerID=40&md5=e15919e4769d71156d850b6eb8b42e33