Novel integration strategy coupling codon and fermentation optimization for efficiently enhancing sarcosine oxidase (SOX) production in recombinant Escherichia coli

Abstract

Sarcosine oxidase (SOX) was an important diagnostic enzyme in the renal function examination. An integrated strategy coupling codon and fermentation optimization was firstly proposed for improving SOX production from recombinant E. coli in 3-L fermentor. The expression suppression (gene phase) and poor balance between SOX expression and cell growth (fermentation phase) in the traditional SOX production were respectively improved by the multiple strategies. Based on the codon bias, the expression suppression was weakened via codon optimization and SOX activity reached 1,521 U/L. The induction toxicity was reduced with the optimal induction condition and SOX production increased to 4,015 U/L. Based on the kinetic analysis of μ x and μ p , a better balance between cell growth and expression was achieved by the two-stage pH-stat control strategy. The SOX activity was further improved to 8,490 U/L and fermentation cycle was also significantly shortened from 44 to 32 h. The substrate inhibition was weakened with a constant feeding fed-batch. With the assistance of integrated strategy, the activity and productivity reached 12,466 U/L and 389.6 U/(L h), respectively, or 3.1-fold and 4.3-fold of the uncontrolled fermentation. The strategy would be also useful in the industrial application of other similar enzymes.

Expression and production of recombinant scorpine as a potassium channel blocker protein in Escherichia coli

“…Most proteins and industrial enzymes can be produced with fermentation process and genetic engineering . However, low expression of recombinant heterologous proteins and weak equilibrium between cell growth and expression level are still a major problem . Based on previous studies, induction condition, cell growth, and substrate inhibition have a significant impact on the efficiency of fermentation .…”

Molecular modification, expression and purification of new subtype antioxidant peptide from Pinctada fucata by recombinant Escherichia coli to improve antioxidant-activity

“…Meanwhile, the antioxidant peptides NPFMAP sequence was deposited in the GenBank and could be accessed through accession number MG680495. Next, the DNA sequence encoding the 61 amino acids of NPFMAP was synthesized and codon-optimized for E. coli expression, using Primer Premier 5.0 (Tong et al 2015).Meanwhile, the NPFMAP sequence was optimized using high-usage E. coli codons to ensure a higher yield. DNA constructs were generated by overlap extension polymerase chain reaction (OE-PCR) (Xiao and Pei 2011).…”