Opportunistic Sampling of Roadkill as an Entry Point to Accessing Natural Products Assembled by Bacteria Associated with Non-anthropoidal Mammalian Microbiomes

J Nat Prod. 2017 Mar 24;80(3):598-608. doi: 10.1021/acs.jnatprod.6b00772. Epub 2016 Nov 21.

Abstract

Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mammals. This initiative was made possible through the establishment of a newly created discovery pipeline, which couples laser ablation electrospray ionization mass spectrometry (LAESIMS) with bioassay testing, to target biologically active metabolites from microbiome-associated bacteria. To illustrate this process, this report focuses on samples obtained from the ear of a roadkill opossum (Dideiphis virginiana) as the source of two bacterial isolates (Pseudomonas sp. and Serratia sp.) that produced several new and known cyclic lipodepsipeptides (viscosin and serrawettins, respectively). These natural products inhibited biofilm formation by the human pathogenic yeast Candida albicans at concentrations well below those required to inhibit yeast viability. Phylogenetic analysis of 16S rRNA gene sequence libraries revealed the presence of diverse microbial communities associated with different sites throughout the opossum carcass. A putative biosynthetic pathway responsible for the production of the new serrawettin analogues was identified by sequencing the genome of the Serratia sp. isolate. This study provides a functional roadmap to carrying out the systematic investigation of the genomic, microbiological, and chemical parameters related to the production of natural products made by bacteria associated with non-anthropoidal mammalian microbiomes. Discoveries emerging from these studies are anticipated to provide a working framework for efforts aimed at augmenting microbiomes to deliver beneficial natural products to a host.

Publication types

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

MeSH terms

  • Animals
  • Animals, Wild
  • Biological Products / chemistry*
  • Genetic Variation
  • Humans
  • Lipoproteins / chemistry*
  • Mammals
  • Microbiota*
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Peptides, Cyclic / chemistry*
  • Phylogeny
  • Pseudomonas / chemistry*
  • RNA, Ribosomal, 16S / genetics*
  • Serratia / chemistry*
  • Spectrometry, Mass, Electrospray Ionization
  • Vertebrates

Substances

  • Biological Products
  • Lipoproteins
  • Peptides, Cyclic
  • RNA, Ribosomal, 16S
  • serrawettin W2