title: Effects of UPR and ERAD pathway on the prolyl endopeptidase production in Pichia pastoris by controlling of nitrogen source.
abstract: Prolyl endopeptidase (PEP) is very useful in various industries, while the high cost of enzyme production remains a major obstacle for its industrial applications. Pichia pastoris has been used for the PEP production; however, the fermentation process has not be investigated and little is known about the impact of excessive PEP production on the host cell physiology. Here, we optimized the nitrogen source to improve the PEP expression level and further evaluated the cellular response including UPR and ERAD. During methanol induction phase the PEP activity (1583 U/L) was increased by 1.48-fold under the optimized nitrogen concentration of NH4+(300 mmol/L) and casamino acids [1.0% (w/v)] in a 3-L bioreactor. Evaluated by RT-PCR the UPR and ERAD pathways were confirmed to be activated. Furthermore, a strong decrease of ERAD-related gene transcription was observed with the addition of nitrogen source, which contributed to a higher PEP expression level.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.|State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, People's Republic of China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.|State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Jiang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China. bioyuxw@aliyun.com.|State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, People's Republic of China. bioyuxw@aliyun.com.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Yu
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China. yxu@jiangnan.edu.cn.|State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, People's Republic of China. yxu@jiangnan.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism; D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D003470:Culture Media / Q000737:chemistry; D060746:Endoplasmic Reticulum-Associated Degradation / Q000235:genetics*; D005285:Fermentation; D000432:Methanol / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010843:Pichia / Q000201:enzymology* / Q000235:genetics; D000085822:Prolyl Oligopeptidases; D012331:RNA, Fungal / Q000235:genetics; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D064751:Ammonium Compounds; D003470:Culture Media; D012331:RNA, Fungal; D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases; D009584:Nitrogen; D000432:Methanol
keywords: ERAD; Nitrogen source; Pichia pastoris; Prolyl endopeptidase; UPR