Highly efficient whole-cell biosynthesis of putrescine by recombinant Escherichia coli

Abstract

Putrescine is an amine with high industrial value. At present, the chemical production method used in industry has shortcomings of using unsustainable petroleum raw material and expensive reaction catalyst, unsafe reaction process with inflammables and explosives. Therefore, researchers turn their attention to the biosynthesis of putrescine. Escherichia coli, with the natural pathway for the synthesis of putrescine, is a good choice for producing putrescine as the host strain. In this study, an effective putrescine bio-production platform was built via overexpressing two key pathway enzymes in engineered Escherichia coli PUT2, combining with a well-controlled fermentation strategy. Escherichia coli PUT2 converted arginine to putrescine within 48 h on a 3 L scale, reaching a titer of 26.21 g L−1, and the specific production of putrescine was 1.99 g per unit biomass, with a productivity of 0.54 g L-1 h-1, which obtained the high production efficiency of cell. Compared with the original strain Escherichia coli BL21(DE3), the putrescine titer increased to 79 times. This research offered a promising strategy for putrescine bio-synthesis, laying a foundation for large-scale putrescine bio-production.