Applied Microbiology and Biotechnology

, Volume 44, Issue 1, pp 198–205

Effects of enhanced lysine ε-aminotransferase activity on cephamycin biosynthesis in Streptomyces clavuligerus

  • L. -H. Malmberg
  • W. -S. Hu
  • D. H. Sherman
Applied Microbial and Cell Physiology

DOI: 10.1007/BF00164502

Cite this article as:
Malmberg, L.-., Hu, W.-. & Sherman, D.H. Appl Microbiol Biotechnol (1995) 44: 198. doi:10.1007/BF00164502

Abstract

A recombinant strain of S. clavuligerus (LHM100) that contains an additional copy of the gene (lat) encoding lysine ε-aminotransferase (LAT) was analyzed and compared to the wild-type for intracellular concentrations of primary metabolites involved in cephamycin C biosynthesis. This strain had been shown previously to produce higher levels of the antibiotic because of increased levels of LAT, a rate-limiting enzyme involved in the production of α-amino-adipic acid. The results showed that the overall growth kinetics of the two strains were comparable, including the intracellular concentrations of cysteine, valine and lysine. In contrast, 60% higher antibiotic production was observed in LHM100, which reflected a significant temporal variation in specific metabolite production rate. The time profile of LAT activity was consistently higher in LHM100; however, α-aminoadipic acid levels showed unexpected variation during the growth cycle. These results support the proposal that rate-limiting enzymes in cephamycin C biosynthesis are temporally controlled, and indicate that optimization of metabolite production will require differential overexpression of several biosynthetic genes.

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • L. -H. Malmberg
    • 1
  • W. -S. Hu
    • 1
  • D. H. Sherman
    • 2
  1. 1.Department of Chemical Engineering and Material SciencesUniversity of MinnesotaMinneapolisUSA
  2. 2.Department of Microbiology and Biological Process Technology InstituteUniversity of MinnesotaSt. PaulUSA