Authors: Huaxin Chen Ju Chu Siliang Zhang Yingping Zhuang Jiangchao Qian Yonghong Wang Xiaoqing Hu
Publish Date: 2007/02/28
Volume: 74, Issue: 6, Pages: 1205-1212
Abstract
To develop an efficient way to produce Sadenosylmethionine SAM methionine adenosyltransferase gene mat from Streptomyces spectabilis and Vitreoscilla hemoglobin gene vgb were coexpressed intracellularly in Pichia pastoris both under control of methanolinducible promoter Expression of mat in P pastoris resulted in about 27 times higher specific activity of methionine adenosyltransferase SMAT and about 19 times higher SAM production relative to their respective control suggesting that overexpression of mat could be used as an efficient method for constructing SAMaccumulating strain Under induction concentration of 08 and 24 methanol coexpression of vgb improved though to different extent cell growth SAM production and respiratory rate However the effects of VHb on SAM content specific yield of SAM production and SMAT seemed to be methanol concentrationdependent When cells were induced with 08 methanol no significant effects of VHb expression on SAM content and specific SMAT could be detected When the cells were induced with 24 methanol vgb expression increased SAM content significantly and depressed SMAT remarkably We suggested that under our experimental scheme the presence of VHb might improve ATP synthesis rate and thus improve cell growth and SAM production in the recombinant P pastorisWe are grateful to National High Technology Research and Development Program of China 863 Program No 2002AA217021 2002AA2Z3451 for their financial supports to this research We are also grateful to Prof Y Gong Shanghai Research Center of Biotechnology for supplying plasmid of pIOKvgb
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