Exploring uncharted metabolic space

Environmental studies suggest that a large fraction of the total bacterial diversity has so far resisted cultivation. Many of the uncultivated bacteria belong to large taxonomic groups without cultivated representatives and known functional properties. Considering the importance of bacteria for drug discovery, it has been proposed that these elusive organisms represent a massive untapped resource of novel compounds and biotechnologically useful enzymes. To investigate the biosynthetic potential of microbial dark matter, our laboratory uses metagenomic and single-cell methods focusing on host-associated microbiomes. We provide evidence for the existence of a new environmental candidate phylum, termed "Tectomicrobia", members of which live associated with marine sponges and are metabolically highly talented. These bacteria exhibit a rich and versatile specialized metabolism with bioactive compounds not yet encountered in cultivated bacteria. Functional studies revealed unprecedented types of biosynthetic transformations that are of significant biotechnological interest.