Biobutanol has great potential as biofuel of the future. However, only a few organisms have the natural ability to produce butanol. Amongst them, Clostridium spp. are the most efficient producers. The high toxicity of biobutanol constitutes one of the bottlenecks within the biobutanol production process which often suffers from low final butanol concentrations and yields. Butanol tolerance is a key driver for process optimisation and, therefore, in the search for alternative butanol production hosts. Many Lactobacillus species show a remarkable tolerance to solvents and some Lactobacillus spp. are known to naturally produce 2-butanol from meso-2,3-butanediol (meso-2,3-BTD) during anaerobic sugar fermentations. Lactobacillus diolivorans showed already to be highly efficient in the production of other bulk chemicals using a simple two-step metabolic pathway. Exactly, the same pathway enables this cell factory for 2-butanol production. Due to the inability of L. diolivorans to produce meso-2,3-BTD, a two-step cultivation processes with Serratia marcescens has been developed. S. marcescens is a very efficient producer of meso-2,3-BTD from glucose. The process yielded a butanol concentration of 10 g/L relying on wild-type bacterial strains. A further improvement of the maximum butanol titer was achieved using an engineered L. diolivorans strain overexpressing the endogenous alcohol dehydrogenase pduQ. The two-step cultivation process based on the engineered strain led to a maximum 2-butanol titer of 13.4 g/L, which is an increase of 34%. In this study, L. diolivorans is for the first time described as a good natural producer for 2-butanol from meso-2,3-butanediol. Through the application of a two-step cultivation process with S. marcescens, 2-butanol can be produced from glucose in a one-vessel, two-step microbial process.

中文翻译：

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用二食乳杆菌微生物生产 2-丁醇

生物丁醇作为未来的生物燃料具有巨大的潜力。然而，只有少数生物具有生产丁醇的天然能力。其中，梭菌属。是最有效率的生产者。生物丁醇的高毒性构成了生物丁醇生产过程中的瓶颈之一，该过程通常受到最终丁醇浓度和产量低的影响。丁醇耐受性是工艺优化的关键驱动因素，因此，在寻找替代丁醇生产宿主时。许多乳杆菌属物种对溶剂和一些乳杆菌属物种表现出显着的耐受性。已知在厌氧糖发酵过程中从 meso-2,3-butanediol (meso-2,3-BTD) 自然产生 2-丁醇。Lactobacillus diolivorans 已经显示出在使用简单的两步代谢途径生产其他大量化学品方面非常有效。确切地说，相同的途径使该细胞工厂能够生产 2-丁醇。由于 L. diolivorans 无法产生 meso-2,3-BTD，因此开发了粘质沙雷氏菌的两步培养工艺。S. marcescens 是一种从葡萄糖中非常有效的 meso-2,3-BTD 生产者。依赖于野生型细菌菌株，该过程产生了 10 g/L 的丁醇浓度。使用过表达内源性醇脱氢酶 pduQ 的工程化 L. diolivorans 菌株实现了最大丁醇滴度的进一步提高。基于工程菌株的两步培养过程导致最大 2-丁醇滴度为 13.4 g/L，增加了 34%。在这项研究中，L. diolivorans 首次被描述为从 meso-2,3-butanediol 中生成 2-丁醇的良好天然生产者。通过使用粘质沙门氏菌的两步培养过程，可以在一个容器、两步微生物过程中从葡萄糖生产 2-丁醇。