文献类型：期刊文献

英文题名：Improvement of cell viability and hirudin production by ascorbic acid in Pichia pastoris fermentation

作者：Xiao, Anfeng; Zhou, Xiangshan; Zhou, Li; Zhang, Yuanxing

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2006

卷号：72

期号：4

起止页码：837

外文期刊名：APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000240809600030)】；

语种：英文

摘要：In recombinant Pichia pastoris fermentation for hirudin production, copious cells were not viable and most of the secreted hirudin molecules were C-terminally truncated at the end of fermentation. In this work, the influences of reactive oxygen species (ROS) on cell viability and hirudin production were subsequently studied. In contrast to the untreated control condition, the addition of ascorbic acid at the methanol fed-batch phase could obviously relieve the damage of intracellular ROS to cell membranes. As a result, the cell viability could be increased to 91% from 74% in control at the end of fermentation and the extracellular proteolysis of hirudin reduced. Intact and total hirudin production, by supplying ascorbic acid, could reach 2.90 and 5.03 g/l, respectively, in contrast to 1.75 and 4.70 g/l at the control condition. Ascorbic acid, 4 mmol/l or more, in the fermentation broth increased markedly the production of the intact hirudin, despite a little effect on total hirudin production.