Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, 48149, Münster, Germany,
Appl Microbiol Biotechnol. 2014 Feb;98(4):1913-24. doi: 10.1007/s00253-013-5460-2. Epub 2014 Jan 5.
This study investigated the production of triacylglycerols in cells of the wild type of Escherichia coli and of a strain with a deleted diacylglycerol kinase gene (dgkA). By overexpression of atfA from Acinetobacter baylyi ADP1 and fadD from E. coli in the dgkA deletion mutant, cellular contents of up to 4.9% (w/w) triacylglycerols could be achieved in batch cultivation. Furthermore, heterologous expression of atfA relieves the negative effects of dgkA deletion on growth. Process optimization and fed-batch fermentation resulted in the production of 530 mg l (-1) triacylglycerols and a maximal content of 8.5% (w/w) triacylglycerols of the cell dry mass. This clearly exceeded all previous results concerning triacylglycerol production in E. coli. Furthermore, the production of extracellular free fatty acids and fatty acid ethyl esters was investigated. Like triacylglycerols, both products are potential biofuels, and we show their continuous production in a repeated batch process, with recovery of the production cells.
本研究调查了野生型大肠杆菌细胞和缺失二酰基甘油激酶基因（dgkA）的菌株中三酰基甘油的生产。通过在 dgkA 缺失突变体中过表达来自不动杆菌 ADP1 的 atfA 和来自大肠杆菌的 fadD，在分批培养中可以达到高达 4.9%（w/w）的细胞内三酰基甘油含量。此外，atfA 的异源表达缓解了 dgkA 缺失对生长的负面影响。通过过程优化和补料分批发酵，生产了 530mg/L 的三酰基甘油，细胞干重中三酰基甘油的最大含量为 8.5%（w/w）。这明显超过了以前关于大肠杆菌中三酰基甘油生产的所有结果。此外，还研究了细胞外游离脂肪酸和脂肪酸乙酯的生产。与三酰基甘油一样，这两种产物都是潜在的生物燃料，我们展示了它们在重复分批过程中的连续生产，并回收了生产细胞。
