title: Enhancing pIFN-α production and process stability in fed-batch culture of Pichia pastoris by controlling the methanol concentration and monitoring the responses of OUR/DO levels.
abstract: Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor using an in situ methanol electrode-based feeding process with the control level of methanol concentration linearly increased to 10 g l⁻¹ for the first 20 h and maintained at 10 g l⁻¹ for the rest of expression phase. With this two-stage control process, the highest pIFN-α concentration reached a level of 1.81 g l⁻¹, which was 1.5-fold of that in the previous constant 10 g l⁻¹ induction experiments. There is an improvement of the pIFN-α productivity from more distribution of carbon flux to protein expression. The pIFN-α expression stability could be further enhanced by a simple on-line fault diagnosis method for methanol overfeeding based on oxygen uptake rate changing patterns. By implementing corrective action of feeding glycerol after fault detection, the production yield increased to twice the amount it would have been without the diagnosis.
authors.affiliation: Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Min-Jie
authors.initials: MJ
authors.lastname: Gao
authors.forename: Xiao-Bei
authors.initials: XB
authors.lastname: Zhan
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Zheng
authors.forename: Jian-Rong
authors.initials: JR
authors.lastname: Wu
authors.forename: Shi-Juan
authors.initials: SJ
authors.lastname: Dong
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Zhong-Ping
authors.initials: ZP
authors.lastname: Shi
authors.forename: Chi-Chung
authors.initials: CC
authors.lastname: Lin
mesh_terms: D000818:Animals; D061249:Batch Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D019149:Bioreactors / Q000382:microbiology; D003470:Culture Media / Q000032:analysis / Q000378:metabolism; D005285:Fermentation; D016898:Interferon-alpha / Q000096:biosynthesis* / Q000235:genetics; D000432:Methanol / Q000032:analysis / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D013552:Swine
chemical_list: D003470:Culture Media; D016898:Interferon-alpha; D011994:Recombinant Proteins; D010100:Oxygen; D000432:Methanol