Coculture of Marine Invertebrate-Associated Bacteria and Interdisciplinary Technologies Enable Biosynthesis and Discovery of a New Antibiotic, Keyicin

ACS Chem Biol. 2017 Dec 15;12(12):3093-3102. doi: 10.1021/acschembio.7b00688. Epub 2017 Nov 22.


Advances in genomics and metabolomics have made clear in recent years that microbial biosynthetic capacities on Earth far exceed previous expectations. This is attributable, in part, to the realization that most microbial natural product (NP) producers harbor biosynthetic machineries not readily amenable to classical laboratory fermentation conditions. Such "cryptic" or dormant biosynthetic gene clusters (BGCs) encode for a vast assortment of potentially new antibiotics and, as such, have become extremely attractive targets for activation under controlled laboratory conditions. We report here that coculturing of a Rhodococcus sp. and a Micromonospora sp. affords keyicin, a new and otherwise unattainable bis-nitroglycosylated anthracycline whose mechanism of action (MOA) appears to deviate from those of other anthracyclines. The structure of keyicin was elucidated using high resolution MS and NMR technologies, as well as detailed molecular modeling studies. Sequencing of the keyicin BGC (within the Micromonospora genome) enabled both structural and genomic comparisons to other anthracycline-producing systems informing efforts to characterize keyicin. The new NP was found to be selectively active against Gram-positive bacteria including both Rhodococcus sp. and Mycobacterium sp. E. coli-based chemical genomics studies revealed that keyicin's MOA, in contrast to many other anthracyclines, does not invoke nucleic acid damage.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anthracyclines / chemistry
  • Anthracyclines / metabolism*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / metabolism*
  • Aquatic Organisms / microbiology*
  • Coculture Techniques
  • Computational Biology
  • Invertebrates / microbiology*
  • Metabolomics
  • Micromonospora / metabolism*
  • Molecular Structure
  • Oligosaccharides / chemistry
  • Oligosaccharides / metabolism*
  • Rhodococcus / metabolism*


  • Anthracyclines
  • Anti-Bacterial Agents
  • Oligosaccharides
  • keyicin