Matsumoto Takuya, Mori Yuki, Tanaka Tsutomu, Kondo Akihiko
Department of Chemical Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan.
J Biosci Bioeng. 2020 Jan;129(1):99-103. doi: 10.1016/j.jbiosc.2019.06.015. Epub 2019 Jul 15.
Bioamination methods using microorganisms have attracted much attention because of the increasing demand for environmentally friendly bioprocesses. n-Butylamine production from glucose in Escherichia coli was demonstrated in this study, which has never been reported because of the absence of n-butylamine-producing pathway in nature. We focused on a transaminase-mediated cascade for bioamination from an alcohol or aldehyde. The cascade can convert an alcohol or an aldehyde to the corresponding amine with l-alanine as an amine donor. Here, n-butyraldehyde, which is a metabolic intermediate in the n-butanol producing pathway, is a potential intermediate for producing n-butylamine using this cascade. Hence, the n-butanol-producing pathway and the transaminase-mediated cascade were combined into a synthetic metabolic pathway for producing n-butylamine from glucose. Firstly, we demonstrated the conversion of n-butanol to n-butylamine using a three enzyme-mediated cascade. n-Butanol was successfully converted to n-butylamine in 92% yield in the presence of l-alanine and ammonium chloride. Then, the n-butanol-producing pathway and transaminase-mediated cascade were introduced into E. coli. Using this system, n-butylamine was successfully produced from glucose as a carbon source at a concentration of 53.2 mg L after 96 h cultivation using a ppc (phosphoenolpyruvate carboxylase)-deficient strain. To the best of our knowledge, this is the first report of the direct production of n-butylamine from glucose, and may provide a starting point for the development of microbial methods to produce other bioamines.
由于对环境友好型生物工艺的需求不断增加，利用微生物的生物胺化方法备受关注。本研究证明了在大肠杆菌中可由葡萄糖生产正丁胺，由于自然界中不存在产生正丁胺的途径，此前从未有过相关报道。我们聚焦于一种转氨酶介导的从醇或醛进行生物胺化的级联反应。该级联反应可以以L-丙氨酸作为胺供体，将醇或醛转化为相应的胺。在此，正丁醛作为正丁醇生产途径中的代谢中间体，是利用该级联反应生产正丁胺的潜在中间体。因此，将正丁醇生产途径和转氨酶介导的级联反应整合为一条从葡萄糖生产正丁胺的合成代谢途径。首先，我们利用三酶介导的级联反应证明了正丁醇向正丁胺的转化。在L-丙氨酸和氯化铵存在的情况下，正丁醇成功转化为正丁胺，产率为92%。然后，将正丁醇生产途径和转氨酶介导的级联反应引入大肠杆菌。使用该系统，以ppc（磷酸烯醇式丙酮酸羧化酶）缺陷型菌株在96小时培养后，以葡萄糖作为碳源成功生产出浓度为53.2mg/L的正丁胺。据我们所知，这是首次报道从葡萄糖直接生产正丁胺，可能为开发生产其他生物胺的微生物方法提供一个起点。
