title: Insights into the lifestyle of uncultured bacterial natural product factories associated with marine sponges.
abstract: The as-yet uncultured filamentous bacteria "Candidatus Entotheonella factor" and "Candidatus Entotheonella gemina" live associated with the marine sponge Theonella swinhoei Y, the source of numerous unusual bioactive natural products. Belonging to the proposed candidate phylum "Tectomicrobia," Candidatus Entotheonella members are only distantly related to any cultivated organism. The Ca E. factor has been identified as the source of almost all polyketide and modified peptides families reported from the sponge host, and both Ca Entotheonella phylotypes contain numerous additional genes for as-yet unknown metabolites. Here, we provide insights into the biology of these remarkable bacteria using genomic, (meta)proteomic, and chemical methods. The data suggest a metabolic model of Ca Entotheonella as facultative anaerobic, organotrophic organisms with the ability to use methanol as an energy source. The symbionts appear to be auxotrophic for some vitamins, but have the potential to produce most amino acids as well as rare cofactors like coenzyme F420The latter likely accounts for the strong autofluorescence of Ca Entotheonella filaments. A large expansion of protein families involved in regulation and conversion of organic molecules indicates roles in host-bacterial interaction. In addition, a massive overrepresentation of members of the luciferase-like monooxygenase superfamily points toward an important role of these proteins in Ca Entotheonella. Furthermore, we performed mass spectrometric imaging combined with fluorescence in situ hybridization to localize Ca Entotheonella and some of the bioactive natural products in the sponge tissue. These metabolic insights into a new candidate phylum offer hints on the targeted cultivation of the chemically most prolific microorganisms known from microbial dark matter.
authors.affiliation: Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zurich, 8093 Zurich, Switzerland.|Junior Research Group Synthetic Microbiology, Friedrich Schiller University at the Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, 07745 Jena, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Lackner
authors.affiliation: Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zurich, 8093 Zurich, Switzerland.
authors.forename: Eike Edzard
authors.initials: EE
authors.lastname: Peters
authors.affiliation: Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zurich, 8093 Zurich, Switzerland.
authors.forename: Eric J N
authors.initials: EJ
authors.lastname: Helfrich
authors.affiliation: Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zurich, 8093 Zurich, Switzerland; jpiel@ethz.ch.
authors.forename: Jörn
authors.initials: J
authors.lastname: Piel
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D059001:Aquatic Organisms / Q000378:metabolism* / Q000382:microbiology*; D001419:Bacteria / Q000378:metabolism*; D001688:Biological Products / Q000378:metabolism*; D054884:Host-Pathogen Interactions / Q000502:physiology; D010802:Phylogeny; D048630:Polyketide Synthases / Q000378:metabolism; D011161:Porifera / Q000378:metabolism* / Q000382:microbiology*; D040901:Proteomics / Q000379:methods; D012256:Riboflavin / Q000031:analogs & derivatives / Q000378:metabolism; D013559:Symbiosis / Q000502:physiology
chemical_list: D000596:Amino Acids; D001688:Biological Products; C015084:coenzyme F420; D048630:Polyketide Synthases; D012256:Riboflavin
keywords: genomics; natural products; proteomics; symbiosis; uncultivated bacteria