Fraunhofer Institut für Molekularbiologie und Angewandte Okologie, Forckenbeckstrasse 6, 52074 Aachen, Germany.
Appl Environ Microbiol. 2009 Dec;75(24):7610-6. doi: 10.1128/AEM.01774-09. Epub 2009 Oct 23.
Several microorganisms are known for their efficient anaerobic conversion of glycerol to 1,3-propanediol, with Clostridium diolis DSM 15410 as one of the better performers in terms of molar yield and volumetric productivity. However, this performance is still insufficient to compete with established chemical processes. Previous studies have shown that high concentrations of 1,3-propanediol, glycerol, and fermentation side products can limit the productivity of C. diolis DSM 15410. Here, we describe the use of genome shuffling for improved 1,3-propanediol fermentation by the strict anaerobe C. diolis DSM 15410. By using chemical mutagenesis, strains with superior substrate and product tolerance levels were isolated and higher product yields were obtained. These superior strains were then used for genome shuffling and selection for 1,3-propanediol and organic acid tolerance. After four rounds of genome shuffling and selection, significant improvements were observed, with one strain attaining a 1,3-propanediol volumetric yield of 85 g/liter. This result represents an 80% improvement compared to the yield from the parental wild-type strain.
已知有几种微生物能够高效地将甘油厌氧转化为 1,3-丙二醇，其中 Clostridium diolis DSM 15410 在摩尔产率和容积产率方面表现较好。然而，其性能仍不足以与成熟的化学工艺竞争。先前的研究表明，高浓度的 1,3-丙二醇、甘油和发酵副产物会限制 C. diolis DSM 15410 的生产力。在这里，我们描述了使用基因组改组来提高严格厌氧菌 C. diolis DSM 15410 的 1,3-丙二醇发酵性能。通过使用化学诱变剂，分离出具有较高底物和产物耐受性的菌株，并获得了更高的产物产率。然后，将这些优良菌株用于基因组改组和选择，以提高 1,3-丙二醇和有机酸的耐受性。经过四轮基因组改组和选择，观察到显著的改进，其中一个菌株的 1,3-丙二醇容积产率达到 85 g/L。与亲本野生型菌株的产率相比，这一结果提高了 80%。
