Department of Life Sciences and Chemistry, Jacobs University gGmbH, Campus Ring 1, 28759 Bremen, Germany.
Department of Life Sciences and Chemistry, Jacobs University gGmbH, Campus Ring 1, 28759 Bremen, Germany.
Biotechnol Adv. 2019 Nov 1;37(6):107378. doi: 10.1016/j.biotechadv.2019.03.017. Epub 2019 Mar 28.
Glycerol is an interesting alternative carbon source in industrial bioprocesses due to its higher degree of reduction per carbon atom compared to sugars. During the last few years, significant progress has been made in improving the well-known industrial platform organism Saccharomyces cerevisiae with regard to its glycerol utilization capability, particularly in synthetic medium. This provided a basis for future metabolic engineering focusing on the production of valuable chemicals from glycerol. However, profound knowledge about the central carbon catabolism in synthetic glycerol medium is a prerequisite for such incentives. As a matter of fact, the current assumptions about the actual in vivo fluxes active on glycerol as the sole carbon source have mainly been based on omics data collected in complex media or were even deduced from studies with other non-fermentable carbon sources, such as ethanol or acetate. A number of uncertainties have been identified which particularly regard the role of the glyoxylate cycle, the subcellular localization of the respective enzymes, the contributions of mitochondrial transporters and the active anaplerotic reactions under these conditions. The review scrutinizes the current knowledge, highlights the necessity to collect novel experimental data using cells growing in synthetic glycerol medium and summarizes the current state of the art with regard to the production of valuable fermentation products from a carbon source that has been considered so far as 'non-fermentable' for the yeast S. cerevisiae.
甘油作为一种比糖具有更高还原程度的碳原子源，在工业生物过程中是一种很有趣的替代碳源。在过去的几年中，人们在提高众所周知的工业平台生物酵母属酿酒酵母的甘油利用能力方面取得了重大进展，尤其是在合成培养基中。这为未来从甘油生产有价值的化学品的代谢工程提供了基础。然而，对合成甘油培养基中中心碳分解代谢的深刻了解是这些激励措施的前提。事实上，目前关于甘油作为唯一碳源时体内实际活性通量的假设主要基于在复杂培养基中收集的组学数据，甚至是从其他不可发酵碳源（如乙醇或乙酸）的研究中推断出来的。已经确定了一些不确定性，特别是涉及乙醛酸循环的作用、相关酶的亚细胞定位、线粒体转运体的贡献以及在这些条件下的活跃的补充反应。该综述审查了当前的知识，强调了在使用在合成甘油培养基中生长的细胞收集新的实验数据的必要性，并总结了目前从一种迄今为止被认为对酵母属酿酒酵母“不可发酵”的碳源生产有价值的发酵产品的最新技术状态。
