Enhanced production of periplasmic interferon alpha-2b by Escherichia coli using ion-exchange resin for in situ removal of acetate in the culture

• Main Authors: Tan, J.S., Ramanan, R.N., Ling, T.C., Shuhaimi, M., Ariff, A.B.
• Format: Article
• Published: Elsevier 2011
• Subjects: Q Science (General)
• Online Access: http://eprints.um.edu.my/14545/
• Institution: Universiti Malaya

The possibility of using in situ addition of anion-exchange resin for the removal of acetate in the culture aimed at improving growth of E. coli and expression of periplasmic human interferon-alpha ab (PrIFN-alpha 2b) was studied in shake flask culture and stirred tank bioreactor. Different types of anion-exchange resin were evaluated and the concentration of anion-exchange resin was optimized using response surface methodology. The addition of anion-exchange resins reduced acetate accumulation in the culture, which in turn, improved growth of E. coli and enhanced PrIFN-alpha 2b expression. The presence of anion-exchange resins did not influence the physiology of the cells. The weak base anion-exchange resins, which have higher affinity towards acetate, yielded higher PrIFN-alpha 2b expression as compared to strong anion-exchange resins. High concentrations of anion-exchange resin showed inhibitory effect towards growth of E. coli as well as the expression of PrIFN-alpha 2b. The maximum yield of PrIFN-alpha 2b in shake flask culture (501.8 mu g/L) and stirred tank bioreactor (578.8 mu g/L) was obtained at ion exchange resin (WA 30) concentration of 12.2 g/L. The production of PrIFN-alpha 2b in stirred tank bioreactor with the addition of ion exchange resin was about 1.8-fold higher than that obtained in fermentation without ion exchange resin (318.4 mu g/L). (C) 2011 Elsevier By. All rights reserved.