Biomedicinals from the phytosymbionts of marine invertebrates: A molecular approach

摘要: Marine invertebrate animals such as sponges, gorgonians, tunicates and bryozoans are sources of biomedicinally relevant natural products, a small but growing number which advancing through clinical trials. Most metazoan anthozoan species harbour commensal microorganisms that include prokaryotic bacteria, cyanobacteria (blue-green algae), eukaryotic microalgae, fungi within host tissues where they reside extra- intra-cellular symbionts. In some sponges these associated microbes may constitute much 40% the holobiont volume. There is now abundant evidence to suggest significant portion bioactive metabolites thought originally be products source animal often synthesized by their symbiotic microbiota. Several anti-cancer from marine have progressed pre-clinical or clinical-trial phases, discodermolide, halichondrin B bryostatin 1, derived microbiotic consortia. Freshwater well recognised for producing numerous structurally diverse cytotoxic secondary suited drug discovery. Sea contain dominant taxa-specific populations cyanobacteria, it phytosymbionts (= photosymbionts) considered true biogenic pharmacologically active polyketides nonribosomally peptides produced sponge. Accordingly, new collections can pre-screened in field presence phytobionts and, together with metagenomic screening using degenerate PCR primers identify key polyketide synthase (PKS) nonribosomal peptide synthetase (NRPS) genes, afford biodiscovery rationale based on therapeutic prospects phytochemical selection. Additionally, cloning biosynthetic expression strategies provide sustainable method supply pharmaceuticals uncultured organisms.