Insights into the lifestyle of uncultured bacterial natural product factories associated with marine sponges

The 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.