[Effect of mufti-gene knockout of L-tryptophan transport system on L-tryptophan production in Escherichia coli]

Sheng Wu Gong Cheng Xue Bao. 2011 Dec;27(12):1765-72.
[Article in Chinese]

Abstract

In Escherichia coli, uptake of L-tryptophan is done by three distinct permeases, encoded by mtr, tnaB, and aroP. Based on the mtr single-gene knockout, we constructed the mtr.tnaB and mtr.aroP double-gene knockout mutants and the mtr.tnaB.aroP triple-gene knockout mutant. The fermentation results showed that the mtr.tnaB and mtr.aroP knockout mutants produced 1.38 g/L and 1.27 g/L L-tryptophan, respectively, which was 17% and 9% higher than that of the mtr knockout mutant. However, the mtr.tnaB.aroP knockout mutant was significantly affected on cell growth and only produced 0.63 g/L L-tryptophan. During the fed-batch fermentation in a 3-L fermentor, the mtr.tnaB knockout mutant produced 12.2 g/L L-tryptophan, which was 27% higher than that of the mtr knockout mutant. This study demonstrates the effect of multi-gene knockouts of L-tryptophan transport system of Escherichia coli on the biosynthesis of L-tryptophan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / genetics*
  • Biological Transport
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics*
  • Fermentation
  • Gene Knockout Techniques
  • Membrane Transport Proteins / genetics*
  • Membrane Transport Proteins / metabolism
  • Mutant Proteins / metabolism
  • Tryptophan / biosynthesis*
  • Tryptophan / genetics
  • Tryptophan / metabolism

Substances

  • Amino Acid Transport Systems
  • Escherichia coli Proteins
  • Membrane Transport Proteins
  • Mutant Proteins
  • mtr protein, E coli
  • Tryptophan