Metabolic engineering of for agmatine production.

Agmatine is a kind of important biogenic amine. The chemical synthesis route is not a desirable choice for industrial production of agmatine. To date, there are no reports on the fermentative production of agmatine by microorganism. In this study, the base strain AUX4 (JM109 ∆ ∆ ∆ ∆) capable of excreting agmatine into the culture medium was first constructed by sequential deletions of the and genes encoding the ornithine decarboxylase isoenzymes, the gene encoding agmatine ureohydrolase and the regulation gene responsible for the negative control of the regulon. The gene encoding arginine decarboxylase harboured by the pKK223-3 plasmid was overexpressed in AUX4, resulting in the engineered strain AUX5. The batch and fed-batch fermentations of the AUX5 strain were conducted in a 3-L bioreactor, and the results showed that the AUX5 strain was able to produce 1.13 g agmatine L with the yield of 0.11 g agmatine g glucose in the batch fermentation and the fed-batch fermentation of AUX5 allowed the production of 15.32 g agmatine L with the productivity of 0.48 g agmatine L h, demonstrating the potential of as an industrial producer of agmatine.