Effects of aroP gene disruption on L-tryptophan fermentation

Abstract

The production of L-tryptophan through chemical synthesis, direct fermentation, bioconversion and enzymatic conversion has been reported. However, the role of the transport system for the aromatic amino acids in L-tryptophan producing strains has not been fully explored. In this study, the aroP gene of the L-tryptophan producing Escherichia coli TRTH strain was disrupted using Red recombination technology and an aroP mutant E. coli TRTH ΔaroP was constructed. Fed-batch fermentation of E. coli TRTH ΔaroP was carried out in 30-L fermentor to investigate the L-tryptophan production. Compared with E. coli TRTH, the aroP mutant was able to maintain a higher growth rate during the exponential phase of the fermentation and the L-tryptophan production increased by 13.3%.

Keywords

Escherichia coli TRTH / aroP / L-tryptophan fermentation / Red recombination

References

[1] Scheper T, Faurie R, Thommel J. Advances in Biochemical Engineering Biotechnology. New York, Berlin, Heidelberg: Springer, 2003, 1-35

[2] Yanofsky C, Horn V, Gollnick P. Physiological studies of tryptophan transport and tryptophanase operon induction in Escherichia coli. Journal of Biotechnology, 1991, 173(19): 6009-6017

[3] Brown K D. Formation of aromatic amino acid pools in E. coli K-12. Journal of Biotechnology, 1970, 104: 177-188

[4] Sarsero J P, Wookey P J, Gollnick P, Yanofsky C, Pittard A J. A new family of integral membrane proteins involved in transport of aromatic amino acids in Escherichia coli. Journal of Biotechnology, 1991, 173(10): 3231-3234

[5] Honoré N, Cole S T. Nucleotide sequence of the aroP gene encoding the general aromatic amino acid transport protein of Escherichia coli K-12: homology with yeast transport proteins. Nucleic Acids Research, 1990, 18(3): 653

[6] Koyanagi T, Katayama T, Suzuki H, Kumagai H. Identification of the LIV-I/LS system as the third phenylalanine transporter in Escherichia coli K-12. Journal of Biotechnology, 2004, 186(2): 343-350

[7] Jack D L, Paulsen I T, Saier M H. The amino acid/polyamine/organocation (APC) superfamily of transporters specific for amino acids, polyamines and organocations. Microbiology, 2000, 146(Pt 8): 1797-1814

[8] Milner J L, Vink B, Wood J M. Transmembrane amino acid flux in bacterial cells. Critical Reviews in Biotechnology, 1987, 5(1): 1-47

[9] Heatwole V M, Somerville R L. Cloning, nucleotide sequence, and characterization of mtr, the structural gene for a tryptophan-specific permease of Escherichia coli K-12. Journal of Bacteriology, 1991, 173(1): 108-115

[10] Edwards R M, Yudkin M D. Location of the gene for the low-affinity tryptophan-specific permease of Escherichia coli. Biochemical Journal, 1982, 204(2): 617-619

[11] Camakaris H, Cowan P, Pittard J. U S. <patent>Patent, 5756345</patent>, 1998-<month>05</month>-<day>26</day>

[12] Krämer R. Systems and mechanisms of amino acid uptake and excretion in prokaryotes. Archives of Microbiology, 1994, 162(1-2): 1-13

[13] Ausubel F M, Kingston R E, Brent R. Short Protocols in Molecular Biology. New York: Wiley, 1995

[14] Rabinowitz J D, Kimball E. Acidic acetonitrile for cellular metabolome extraction from Escherichia coli. Analytical Chemistry, 2007, 79(16): 6167-6173

[15] Huang J, Shi J, Liu Q, Xu Q, Xie X, Wen T, Chen N. Effects of gene pta disruption on L-tryptophan fermentation. Acta Microbiologica Sinica, 2011, 51(4): 480-487

Acknowledgments

This work was supported by the program for Changjiang Scholars and Innovative Research Team in University of China (IRT1166).

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg