Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands; Netherlands Institute for Systems Biology, University of Amsterdam, Amsterdam, The Netherlands; Towards BioSolar Cells Consortium, The Netherlands.
Metab Eng. 2013 Nov;20:121-30. doi: 10.1016/j.ymben.2013.09.008. Epub 2013 Oct 5.
The direct and efficient conversion of CO2 into liquid energy carriers and/or bulk chemicals is crucial for a sustainable future of modern society. Here we describe the production of 2,3-butanediol in Synechocystis sp. PCC6803 expressing a heterologous catabolic pathway derived from enteric- and lactic acid bacteria. This pathway is composed of an acetolactate synthase, an acetolactate decarboxylase and an acetoin reductase. Levels of up to 0.72 g/l (corresponding to 8 mmol/L) of C(4) products, including a level of 0.43 g/l (corresponding to 4.7 mmol/L) 2,3-butanediol production are observed with the genes encoding these three enzymes integrated into the cyanobacterial genome, as well as when they are plasmid encoded. Further optimization studies revealed that Synechocystis expresses significant levels of acetolactate synthase endogenously, particularly under conditions of restricted CO2 supply to the cells. Co-expression of a soluble transhydrogenase or of an NADPH-dependent acetoin reductase allows one to drive the last step of the engineered pathway to near completion, resulting in pure meso-2,3-butanediol being produced.
将二氧化碳直接、高效地转化为液体能源载体和/或大宗化学品，对于现代社会的可持续未来至关重要。在这里，我们描述了在表达源自肠杆菌和乳杆菌的异源分解代谢途径的集胞藻 PCC6803 中生产 2,3-丁二醇。该途径由乙酰乳酸合酶、乙酰乳酸脱羧酶和乙酰丁醇还原酶组成。当这三个酶的基因整合到蓝藻基因组中，以及当它们被质粒编码时，观察到高达 0.72 g/l（相当于 8 mmol/L）的 C(4)产物，包括 0.43 g/l（相当于 4.7 mmol/L）的 2,3-丁二醇产量。进一步的优化研究表明，集胞藻内源表达大量的乙酰乳酸合酶，特别是在细胞受到 CO2 限制供应的条件下。可溶性转氢酶或 NADPH 依赖性乙酰丁醇还原酶的共表达可以使工程途径的最后一步接近完成，从而产生纯的 meso-2,3-丁二醇。
