A novel co-production of cadaverine and succinic acid based on a thermal switch system in recombinant Escherichia coli

Abstract

Background Polyamide (nylon) is an important material, which has aroused plenty of attention from all aspects. PA 5.4 is one kind of nylon with excellent property, which consists of cadaverine and succinic acid. Due to the environmental pollution, bio-production of cadaverine and succinic acid has been more attractive due to the less pollution and environmental friendliness. Microbes, like Escherichia coli, has been employed as cell factory to produce cadaverine and succinic acid. However, the accumulation of cadaverine will cause severe damage on cells resulting in inhibition on cell growth and cadaverine production. Herein, a novel two stage co-production of succinic acid and cadaverine was designed based on an efficient thermos-regulated switch to avoid the inhibitory brought by cadaverine. Results The fermentation process was divided into two phase, one for cell growth and lysine production and the other for cadaverine and succinic acid synthesis. The genes of ldhA and ackA were deleted to construct succinic acid pathway in cadaverine producer strain. Then, a thermal switch system based on pR/pL promoter and CI857 was established and optimized. The fermentation conditions were investigated that the optimal temperature for the first stage was determined as 33 ℃ and the optimal temperature for the second stage was 39 ℃. Additionally, the time to shifting temperature was identified as the fermentation anaphase. For further enhance cadaverine and succinic acid production, a scale-up fermentation in 5 L bioreactor was operated. As a result, the titer, yield and productivity of cadaverine was 55.58 g/L, 0.38 g/g glucose and 1.74 g/(L·h), respectively. 28.39 g/L of succinic acid was also obtained with yield of 0.19 g/g glucose. Conclusion The succinic acid metabolic pathway was constructed into cadaverine producer strain to realize the co-production of succinic acid and cadaverine. This study provided a novel craft for industrial co-production of cadaverine and succinic acid.

Advances in succinic acid production: the enhancement of CO2 fixation for the carbon sequestration benefits

“…Linked-fermentation strategies can help to produce multiple products at once and the substrates can be more fully utilized ( Zhang et al, 2017 ; Gao et al, 2022 ; Yin and Wang, 2022 ). Saccharomyces cerevisiae and Actinobacillus succinogenes were co-cultured in the hydrolysate of sugarcane bagasse.…”

“…There are other similar substrate co-fermentation strategies, such as co-production of SA and cadaverine ( Gao et al, 2022 ). The SA pathway was introduced into cadaverine-producing strains, and a thermal switch system was established and optimized to realize a two-stage co-production.…”