Effect of redox potential on the gene expression of Saccharomyces cerevisiae during very-high-gravity ethanol fermentation

超重力乙醇发酵过程中氧化还原电位对酿酒酵母基因表达的影响

• 批准号: 216816-2013
• 负责人: Lin, YenHan
• 金额: $ 1.6万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=637860
• 关键词: Effect; redox; potential; gene; expression; Effect; redox; potential; gene; expression

One of the objectives of the proposal is to study the effect of redox potential on the gene expression of Saccharomyces cerevisiae during very-high-gravity (VHG) ethanol fermentation. To achieve the stated objective, a continuous redox potential-controlled fermentation process will be developed, so that VHG ethanol fermentation can be operated at a specified redox potential level. Once steady state is established, yeast cells are harvested and RNAs are extracted. Microarray technology is then applied to obtain whole gene expression profile under a specified redox potential level. As a result, correlation between gene expression pattern and redox potential is established. The genes modulated by redox potential will be identified and their metabolic functions relating to ethanol production under VHG conditions will be elucidated. It is known that NADH/NAD+ is a key reducing equivalent pair inside a cell. It modulates intracellular redox potential balance. To maintain the balance, specific metabolic pathway is re-routed towards the production of certain metabolite, such as ethanol, glycerol during ethanol fermentation. Until now, a relationship between extracellular redox potential and intracellular reducing equivalent pairs is lacking. The second objective of the proposal is to utilize the above-noted fermentation process in conjunction with microarray technology to establish the missing linkage between the two. The short-term objectives include (1) to develop redox potential-controlled VHG ethanol fermentation process, and (2) to elucidate and to establish correlations between extracellular redox potential and yeast gene expression patterns. Based on findings obtained from short-term objectives, the long-term objectives include (1) to develop novel VHG ethanol fermentation strategies at molecular level, and (2) to design genetic engineering strategies to improve performance of S. cerevisiae during ethanol production. Although the proposed project is targeting at Saccharomyces spp. for ethanol production, the same approach can also be adopted and implemented to investigate butanol production when using Clostridium spp, either native or genetically modified.

该提案的目标之一是研究氧化还原电位对酿酒酵母在非常高的乙醇发酵过程中酿酒酵母基因表达的影响。为了实现既定的目标，将开发连续的氧化还原电势控制的发酵过程，以便可以在指定的氧化还原电位水平上进行VHG乙醇发酵。一旦建立稳态，就收获酵母细胞并提取RNA。然后，将微阵列技术应用于在指定的氧化还原电位水平下获得整个基因表达谱。结果，建立了基因表达模式与氧化还原电位之间的相关性。将确定由氧化还原电位调节的基因，并将阐明其与乙醇产生有关的代谢功能。众所周知，NADH/NAD+是一个键降低单元内的钥匙。它调节细胞内氧化还原电位平衡。为了维持平衡，特定的代谢途径被重新列入某些代谢产物的产生，例如乙醇发酵过程中的乙醇，甘油。到目前为止，缺乏细胞外氧化还原电位与细胞内还原等效对之间的关​​系。该提案的第二个目标是利用与微阵列技术结合使用上述发酵过程来建立两者之间缺失的联系。短期目标包括（1）开发氧化还原电位控制的VHG乙醇发酵过程，以及（2）阐明和建立细胞外氧化还原电位和酵母基因表达模式之间的相关性。基于从短期目标获得的发现，长期目标包括（1）在分子水平开发新型VHG乙醇发酵策略，以及（2）设计基因工程策略以提高乙醇生产过程中酿酒酵母的性能。尽管拟议的项目是针对Saccharomyces spp的。对于乙醇的产生，也可以采用和实施相同的方法来研究丁醇在使用天然或遗传修饰的梭状芽胞杆菌SPP时的生产。