A novel riboregulator switch system of gene expression for enhanced microbial production of succinic acid
In this paper, a novel riboregulator Switch System of Gene Expression including an OFF-TO-ON switch and an ON-TO-OFF switch was designed to regulate the expression state of target genes between “ON” and “OFF” by switching the identifiability of ribosome recognition site (RBS) based on the thermodynamic stability of different RNA–RNA hybridizations between RBS and small noncoding RNAs. The proposed riboregulator switch system was employed for the fermentative production of succinic acid using an engineered strain of E. coli JW1021, during which the expression of mgtC gene was controlled at “ON” state and that of pepc and ecaA genes were controlled at the “OFF” state in the lag phase and switched to the “OFF” and “ON” state once the strain enters the logarithmic phase. The results showed that using the strain of JW1021, the yield and productivity of succinic acid can reach 0.91 g g−1 and 3.25 g L−1 h−1, respectively, much higher than those using the strains without harboring the riboregulator switch system.
KeywordsSwitch of gene expression Gene regulation RBS Ribosome Succinic acid
We thank the Dr. Rachel Chen (Georgia Tech, Atlanta, USA) for helping data analysis. This work is financially supported by the National Key R&D Program of China (2017YFB0603105), the National Natural Science Foundation of China (21606026, 21776025), the Fundamental Research Funds for the Central Universities (106112017CDJXY220005, 106112017CDJXF220009, 106112017CDJPT220001, 106112017CDJQJ228809, and 106112017CDJXFLX0014), and China Scholarship Council (201506050056).
- 1.Balzer GJ, Thakker C, Bennett GN, San KY (2013) Metabolic engineering of Escherichia coli to minimize byproduct formate and improving succinate productivity through increasing NADH availability by heterologous expression of NAD(+)-dependent formate dehydrogenase. Metab Eng 20:1–8CrossRefPubMedGoogle Scholar
- 4.Clark DP (1989) The fermentation pathways of Escherichia coli. FEMS Microbiol Rev 63:223–234Google Scholar
- 8.Gibson DG, Glass JI, Lartigue C, Noskov VN, Chuang RY, Algire MA, Benders GA, Montague MG, Ma L, Moodie MM, Merryman C, Vashee S, Krishnakumar R, Assas-Garcia N, Andrews-Pfannkoch C, Denisova EA, Young L, Qi ZQ, Segall-Shapiro TH, Calvey CH, Parmar PP, Hutchison CA, Smith HO, Venter JC (2010) Creation of a bacterial cell controlled by a chemically synthesized genome. Science 329(5987):52–56CrossRefPubMedGoogle Scholar
- 27.Sugiyama H, Hiwa H, Makino K, Kakunaga T (1988) Strong transcriptional promoter in the 5′ upstream region of the human beta-actin gene. Gene 6:135–139Google Scholar
- 36.Werpy T, Petersen G (2004) Top value added chemicals from biomass Department of energy, Washington, DC, pp 31–33Google Scholar
- 37.Wibur KM, Anderson NG (1948) Electrometric and colorimetric determination of carbonic anhydrase. J Biol Chem 176:147–154Google Scholar