文献类型：期刊文献

英文题名：A systematical investigation on the genetic stability of multi-copy Pichia pastoris strains

作者：Zhu, Taicheng[1];Guo, Meijin[1,2];Sun, Chen[1];Qian, Jiangchao[1];Zhuang, Yingping[1];Chu, Ju[1];Zhang, Siliang[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Jiangxi Agr Univ, Dept Biotechnol, Nanchang 330045, Peoples R China

年份：2009

卷号：31

期号：5

起止页码：679

外文期刊名：BIOTECHNOLOGY LETTERS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000265084500010)】；

基金：This research was partially supported by grants from National Natural Science Foundation of China (No. 30560006) and High-tech Research Plan of China (863) (2007AA100601). We also thank Dr Hong Hoi Ting (Director of GeneMedix plc, UK) for critical reading of the manuscript.

语种：英文

外文关键词：Copy number; Genetic stability; Multi-copy; Pichia pastoris; Porcine insulin precursor

摘要：A battery of Pichia pastoris transformants, G1, G6, A2, A3, C3, carrying 1, 6, 12, 18 and 29 copies of porcine insulin precursor (PIP) gene, were employed to investigate the genetic stability of these multi-copy P. pastoris strains. Both G6 and C3 maintained their original copy numbers in serial culture without methanol induction for 35 generations. With methanol as an inducer and carbon source, G1 and G6 remained stable but the average copy numbers (ACNs) of PIP gene in A2, A3, C3 were decreased to 10, 10 and 15 copies, respectively, after 96 h of induction in shake-flask culture. A PIP copy number distribution analysis of fermentation samples of C3 indicated that the majority of yeast cells have partially or completely lost their PIP genes. In 5-l fermentor culture, the ACNs of PIP gene in A2, A3, C3 were also decreased to 10, 15, 21 copies, respectively, after 72 h of methanol induction.