A kind of arginine decarboxylase genetically engineered bacteria and its high-density fermentation culture method

Abstract

The present invention belongs to the technical field of bioengineering, relates to a high-density cell fermentation method, and particularly relates to an arginine decarboxylase genetically engineeredbacterium and a high-density fermentation culture method thereof. The genetically engineered bacterium uses E.coliK12 as a host and pET28A as a vector, and expresses an adiA gene. A nucleotide sequence of the adiA gene is shown in SEQ ID NO.1. The genetically engineered bacterium can secrete a highly active recombinant arginine decarboxylase, can be applied in pilot scale test high-density fermentation culture, and enables industrialized production of the recombinant arginine decarboxylase to be possible. The fermentation culture method optimizes fermentation culture medium screening and fermentation induction culture conditions, controls supplement time, supplement rate and dosage of glycerin and ammonia water, and supply of carbon source and nitrogen source, adjusts stirring rotating speed and ventilation amount to control oxygen supply, and thus realizes high-density growth of the bacterium and large expression of the target protease.

Description

technical field [0001] The invention belongs to the technical field of bioengineering, and relates to a high-density cell fermentation method, in particular to an arginine decarboxylase genetically engineered bacterium and a high-density fermentation culture method thereof. Background technique [0002] Arginine decarboxylase (Arginine decarboxylase, ADC) is a pyridoxal phosphate (PLP)-dependent decarboxylase, which uses L-arginine as a substrate to generate agmatine after decarboxylation (see figure 1 ). As an important biogenic amine, agmatine has great physiological functions and medical value. At present, enterprises mainly use chemical methods to produce agmatine, which is complicated in the production process and seriously pollutes the environment. The biological enzymatic method has the characteristics of environmental protection and high efficiency. How to use arginine decarboxylase to produce agmatine on a large scale has become a research hotspot. [0003] There ...

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Problems solved by technology

[0004] Based on prior art reports and combined with actual production experience, the inventors found that the recombinant arginine decarboxylase enzyme activity and conversion ability of the obtained recombinant arginine decarboxylase were significantly different in constructing genetically engineered bacteria with genes encoding arginine decarboxylase from different sources, and now The concentration of bacteria in the fermentation liquid obtained by the culture method in the prior art is not high, which leads to the low expression of arginine decarboxylase

At present, there are almost no reports on the use of the obtained recombinant bacteria for high-density fermentation to produce arginine decarboxylase

In addition, different fermentation media, different induction culture methods and different fermentation regulation methods will also affect the fermentation production capacity of genetically engineered bacteria

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