The compatible solutes ectoine and hydroxyectoine are synthesized by many microorganisms as potent osmostress and desiccation protectants. Besides their successful implementation into various skincare products, they are of increasing biotechnological interest due to new applications in the healthcare sector. To meet this growing demand, efficient heterologous overproduction solutions for ectoines need to be found. This study is the first report on the utilization of the non-halophilic biosynthesis enzymes from Acidiphilium cryptum DSM 2389^T for efficient heterologous production of ectoines in Escherichia coli. When grown at low salt conditions (≤ 0.5% NaCl) and utilizing the cheap carbon source glycerol, the production was characterized by the highest specific production of ectoine [2.9 g/g dry cell weight (dcw)] and hydroxyectoine (2.2 g/g dcw) reported so far and occurred at rapid specific production rates of up to 345 mg/(g dcw × h). This efficiency in production was related to an unprecedented carbon source conversion rate of approx. 60% of the theoretical maximum. These findings confirm the unique potential of the here implemented non-halophilic enzymes for ectoine production processes in E. coli and demonstrate the first efficient heterologous solution for hydroxyectoine production, as well as an extraordinary efficient low-salt ectoine production.

中文翻译：

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通过利用来自 Acidiphilium cryptum 的非嗜盐基因簇提高大肠杆菌异源胞嘧啶的生产率。

相容的溶质四氢嘧啶和羟基四氢嘧啶由许多微生物合成，作为有效的渗透压和干燥保护剂。除了它们在各种护肤产品中的成功应用外，由于在医疗保健领域的新应用，它们在生物技术方面的兴趣也越来越大。为了满足这种不断增长的需求，需要为四氢嘧啶找到有效的异源过量生产解决方案。本研究是关于利用来自Acidiphilium cryptum DSM 2389 ^T的非嗜盐生物合成酶在大肠杆菌中高效异源生产四氢嘧啶的首次报告. 当在低盐条件（≤ 0.5% NaCl）下生长并利用廉价的碳源甘油时，生产的特点是四氢嘧啶 [2.9 g/g 干细胞重量 (dcw)] 和羟基四氢嘧啶 (2.2 g/g) 的比产量最高dcw) 迄今已报道并以高达 345 mg/(g dcw × h) 的快速比生产率发生。这种生产效率与前所未有的碳源转化率有关。理论最大值的 60%。这些发现证实了此处实施的非嗜盐酶在大肠杆菌中用于四氢嘧啶生产过程的独特潜力，并证明了用于羟基四氢嘧啶生产的第一个有效异源解决方案，以及非常有效的低盐四氢嘧啶生产。