A kind of recombinant Escherichia coli producing 1,5-pentanediamine-succinate and its construction method and application

Abstract

The invention discloses a recombinant Escherichia coli producing 1,5-pentanediamine-succinate. Compared with the recombinant Escherichia coli producing succinate as the starting bacterium, the synthetic ability of 1,5-pentanediamine improve. The present invention also provides a method for constructing recombinant Escherichia coli producing 1,5-pentamethylenediamine-succinate and its application in preparing 1,5-pentamethylenediamine-succinate. The recombinant Escherichia coli HX028-54 producing 1,5-pentanediamine-succinate constructed by the present invention fermented for 96h to produce 0.94mol, 207g / L of 1,5-pentamethylenediamine-succinate, and glucose There is no residue with lysine, which is convenient for later separation and purification, and has great economic value. The production efficiency of the recombinant Escherichia coli HX028‑54‑D further optimized on this basis was further improved.

Description

A kind of recombinant Escherichia coli producing 1,5-pentanediamine-succinate and construction method thereof with application technical field The present invention relates to a kind of recombinant Escherichia coli of producing 1,5-pentanediamine-succinate and its construction method and application, It belongs to the field of biotechnology. Background technique At present, the global nylon output is about 6 million tons, and wherein nylon 66 is the earliest industrialized production and the most widely used. species. However, due to the high technical barriers and investment thresholds, the key intermediate in the production of nylon 66, adiponitrile, has a high price. The current price is around 23,000 yuan / ton. Therefore, if a nylon product that is cheaper than nylon 66 can be developed, it will be extremely Greatly promote the development of nylon industry. Nylon of industrial significance generally has the following three characteristics: 1, dicarboxylic ac...

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Problems solved by technology

Among them, the method of catalyzing the decarboxylation of lysine is the commonly used method for producing 1,5-pentanediamine. Specifically, the cadA gene is constructed on an inducible plasmid for overexpression, and a large amount of CadA greatly increases the production of 1,5-pentanediamine. production efficiency, but this common method for producing 1,5-pentanediamine has the following defects in the process of fermentatively preparing 1,5-pentanediamine-succinate: First, the overexpression of cadA is harmful to cell growth, because Lysine is an essential substance for cell growth. Overexpression of this enzyme will cause lysine in the cell to be competitively catalyzed into 1,5-pentanediamine, which will lead to insufficient lysine for growth and make cells unable to grow normally

In order to avoid this problem, the cadA gene is usually induced after the cells have grown well. ZL201810195975.2 (CN108531494A) was first fermented for 30 hours aerobically, and fermented for another 6 hours after adding the inducer IPTG. It started after a total of 36 hours of preparation Fermentative production of 1,5-pentanediamine-succinate, a waste of time and carbon source

Secondly, the use of plasmids to overexpress cadA must use antibiotics. ZL201810195975.2 (CN108531494A) uses three antibiotics, kanamycin, chloramphenicol, and streptomycin, which not only increases the cost of fermentation, but also increases the treatment of sewage containing antibiotics cost

Moreover, plasmid loss is an inevitable problem during the overexpression process, resulting in the inability of some cells to express the cadA gene, which is not conducive to the production of 1,5-pentanediamine-succinate

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