Wiebe Marilyn G, Rintala Eija, Tamminen Anu, Simolin Helena, Salusjärvi Laura, Toivari Mervi, Kokkonen Juha T, Kiuru Jari, Ketola Raimo A, Jouhten Paula, Huuskonen Anne, Maaheimo Hannu, Ruohonen Laura, Penttilä Merja
VTT Technical Research Centre of Finland, Finland.
FEMS Yeast Res. 2008 Feb;8(1):140-54. doi: 10.1111/j.1567-1364.2007.00234.x. Epub 2007 Apr 10.
Saccharomyces cerevisiae CEN.PK113-1A was grown in glucose-limited chemostat culture with 0%, 0.5%, 1.0%, 2.8% or 20.9% O2 in the inlet gas (D=0.10 h(-1), pH 5, 30 degrees C) to determine the effects of oxygen on 17 metabolites and 69 genes related to central carbon metabolism. The concentrations of tricarboxylic acid cycle (TCA) metabolites and all glycolytic metabolites except 2-phosphoglycerate+3-phosphoglycerate and phosphoenolpyruvate were higher in anaerobic than in fully aerobic conditions. Provision of only 0.5-1% O2 reduced the concentrations of most metabolites, as compared with anaerobic conditions. Transcription of most genes analyzed was reduced in 0%, 0.5% or 1.0% O2 relative to cells grown in 2.8% or 20.9% O2. Ethanol production was observed with 2.8% or less O2. After steady-state analysis in defined oxygen concentrations, the conditions were switched from aerobic to anaerobic. Metabolite and transcript levels were monitored for up to 96 h after the transition, and this showed that more than 30 h was required for the cells to fully adapt to anaerobiosis. Levels of metabolites of upper glycolysis and the TCA cycle increased following the transition to anaerobic conditions, whereas those of metabolites of lower glycolysis generally decreased. Gene regulation was more complex, with some genes showing transient upregulation or downregulation during the adaptation to anaerobic conditions.
酿酒酵母CEN.PK113 - 1A在葡萄糖受限的恒化器培养中生长，进气流中的氧气含量分别为0%、0.5%、1.0%、2.8%或20.9%（稀释率D = 0.10 h⁻¹，pH 5，30℃），以确定氧气对17种代谢物和69个与中心碳代谢相关基因的影响。除2 - 磷酸甘油酸 + 3 - 磷酸甘油酸和磷酸烯醇丙酮酸外，三羧酸循环（TCA）代谢物和所有糖酵解代谢物的浓度在厌氧条件下高于完全需氧条件。与厌氧条件相比，仅提供0.5 - 1%的氧气会降低大多数代谢物的浓度。相对于在2.8%或20.9%氧气中生长的细胞，在0%、0.5%或1.0%氧气条件下，所分析的大多数基因的转录减少。在氧气含量为2.8%或更低时观察到乙醇产生。在确定的氧气浓度下进行稳态分析后，将条件从需氧切换为厌氧。在转换后长达96小时内监测代谢物和转录水平，结果表明细胞需要超过30小时才能完全适应厌氧状态。向厌氧条件转变后，糖酵解上游和TCA循环的代谢物水平升高，而糖酵解下游代谢物水平通常下降。基因调控更为复杂，一些基因在适应厌氧条件期间表现出短暂的上调或下调。
