关键词: 酵母, S-腺苷甲硫氨酸, ATP代谢, Adk1过表达, 柠檬酸钠补料

Abstract: S-adenosylmethionine (SAM) is a physiological active substance involved in a range of biochemical reactions of all living organisms, the intracellular level of ATP is one of the factors that restrict the synthesis of SAM in yeast. This study cloned and overexpressed the Adk1 gene in Saccharomyces cerevisiae CGMCC 2842. The results showed that the overexpression of Adk1 gene increased  intracellular  ATP  level  by 47.1% and SAM accumulation by 47%. When 6 g·L-1 sodium citrate feeding was investigated at 16 h after inoculation, the level of isocitrate dehydrogenase gene mRNA and IDH activity efficiently increased, which improved the intracellular level of ATP by 39.4% at 24 h. Compared with CK, the SAM accumulation and biomass yield were improved by 79% and 78.8%, respectively. Above results indicated the increase of intracellular ATP levels promoted the transformation of Met into SAM, which provided a strong theoretical basis for the regulation of ATP metabolism and the improvement of SAM synthesis.

Key words: yeast, S-adenosylmethionine, ATP metabolism, Adk1 overexpression, sodium citrate supplement