Conquering isoleucine auxotrophy of Escherichia coli BLR(DE3) to recombinantly produce spider silk proteins in minimal media

Biotechnol Lett. 2007 Nov;29(11):1741-4. doi: 10.1007/s10529-007-9461-z. Epub 2007 Jul 5.


Large-scale production of recombinant spider silk proteins is a long-term goal for their industrial use. Therefore, we have recently developed a process for bacterial production. Due to a highly repetitive gene sequence of spider silks, the host strain E. coli BLR(DE3) was employed since it shows no homologue recombination. Although perfectly suited for production in full media, the BLR strain does not grow in cost-effective minimal media, indicating a previously not reported L: -isoleucine auxotrophy. We provide evidence that mutated threonine deaminase is likely responsible for the detected auxotrophy of BLR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Culture Media
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Fibroins / biosynthesis
  • Isoleucine / metabolism
  • Mutation
  • Point Mutation
  • Recombinant Proteins / biosynthesis*
  • Threonine Dehydratase / chemistry*
  • Threonine Dehydratase / genetics*


  • Culture Media
  • Recombinant Proteins
  • spidroin 1
  • Isoleucine
  • spidroin 2
  • Fibroins
  • Threonine Dehydratase