Proteome analysis guided genetic engineering of Corynebacterium glutamicum S9114 for tween 40-triggered improvement in l-ornithine production

Abstract

Background: l-ornithine is a valuable amino acid with a wide range of applications in the pharmaceutical and food industries. However, the production of l-ornithine by fermentation cannot compete with other methods, because of the low titers produced with this technique. Development of fermentation techniques that result in a high yield of l-ornithine and efficient strategies for improving l-ornithine production are essential. Results: This study demonstrates that tween 40, a surfactant promoter of the production of glutamate and arginine, improves l-ornithine production titers in engineered C. glutamicum S9114. The intracellular metabolism under tween 40 triggered fermentation conditions was explored using a quantitative proteomic approach, identifying 48 up-regulated and 132 down-regulated proteins when compared with the control. Numerous proteins were identified as membrane proteins or functional proteins involved in the biosynthesis of the cell wall. Modulation of those genes revealed that the overexpression of CgS9114_09558 and the deletion of CgS9114_13845, CgS9114_02593, and CgS9114_02058 improved the production of l-ornithine in the engineered strain of C. glutamicum Orn8. The final strain with all the exploratory metabolic engineering manipulations produced 25.46 g/L of l-ornithine, and a yield of 0.303 g l-ornithine per g glucose, which was 30.6% higher than that produced by the original strain (19.5 g/L). Conclusion: These results clearly demonstrate the positive effect of tween 40 addition on l-ornithine accumulation. Proteome analysis was performed to examine the impact of tween 40 addition on the physiological changes in C. glutamicum Orn8 and the results showed several promising modulation targets for developing l-ornithine-producing strains.

Genomics Characterization of an Engineered Corynebacterium glutamicum in Bioreactor Cultivation Under Ionic Liquid Stress

“…We also observed the upregulation of an ABC transporter (Cgl0946 and Cgl0947), a multidrug transport system (MTS) operon, in part regulated by its adjacent two-component system (TCS) (Cgl0948-Cgl0949, also upregulated). MTS offers a natural defense against toxic compounds and is reported to be upregulated in response to the non-ionic surfactant Tween 40 ( Jiang et al, 2020 ). Also, Cgl2312/ ectP , a putative BCCT family transporter was overexpressed in the bioreactor with IL at 24 h time point.…”

Genomics Characterization of an engineered Corynebacterium glutamicum in Bioreactor Cultivation under Ionic Liquid Stress

“…We also observed the upregulation of an ABC transporter (Cgl0946 and Cgl0947), a multidrug transport system (MTS) operon, in part regulated by its adjacent two-component system (TCS) (Cgl0948-Cgl0949, also upregulated). MTS offers a natural defense against toxic compounds and is reported to be upregulated in response to the non-ionic surfactant Tween 40 (Jiang et al, 2020). Also, Cgl2312/ectP, a putative BCCT family transporter was overexpressed Systems Analysis of C. glutamicum in the bioreactor with IL at 24 h time point.…”

Recent Progress on Chemical Production From Non-food Renewable Feedstocks Using Corynebacterium glutamicum

“…Meanwhile, excess biotin, which is unavoidable in lignocellulosic hydrolyzate produced by the pretreatment process, results in a rigid cell membrane that hampers secretion of L-glutamate, restricting cellulosic L-glutamate production (Wen et al, 2018). This unfavorable phenomenon can be reversed by extrinsic addition of osmotic agents, such as Tween 40, ethambutol, and penicillin, a step that not only improves the yield of L-glutamate but also promotes accumulation of L-arginine and L-ornithine during fermentation (Chen M. et al, 2015;Jiang et al, 2020). In addition, the uptake system of biotin is reinforced by overexpression of the bioYMN operon, which encodes biotin transporter, reducing biotin content in corn straw hydrolyzate and stimulating faster cell growth and multiplicative cellulosic L-glutamate production (Han et al, 2019).…”