A Family of Nonribosomal Peptides Modulate Collective Behavior in Pseudovibrio Bacteria Isolated from Marine Sponges**

Abstract

Although swarming motility and biofilms are opposed collective behaviors, both contribute to bacterial survival and host colonization. Pseudovibrio bacteria have attracted attention because they are part of the microbiome of healthy marine sponges. Two‐thirds of Pseudovibrio genomes contain a member of a nonribosomal peptide synthetase‐polyketide synthase gene cluster family, which is also found sporadically in Pseudomonas pathogens of insects and plants. After developing reverse genetics for Pseudovibrio, we isolated heptapeptides with an ureido linkage and related nonadepsipeptides we termed pseudovibriamides A and B, respectively. A combination of genetics and imaging mass spectrometry experiments showed heptapetides were excreted, promoting motility and reducing biofilm formation. In contrast to lipopeptides widely known to affect motility/biofilms, pseudovibriamides are not surfactants. Our results expand current knowledge on metabolites mediating bacterial collective behavior.

Discovery and Biosynthesis of Ureidopeptide Natural Products Macrocyclized via Indole N‐acylation in Marine Microbulbifer spp. Bacteria

“…In the conceivable biosynthetic scheme for 1 , the BulbA NRPS would furnish the ureido linked Phe‐Leu dipeptide, as is consistent with prior reports of ureido bond construction in NRPS‐derived natural products, [9b,14] followed by canonical elongation of the peptide chain with Trp, Ile, Arg, and Leu residues. The organization of the BulbD and BulbE NRPSs is curious.…”

Limited Metabolomic Overlap between Commensal Bacteria and Marine Sponge Holobionts Revealed by Large Scale Culturing and Mass Spectrometry-Based Metabolomics: An Undergraduate Laboratory Pedagogical Effort at Georgia Tech

“…The majority of bacteria isolated in this study could be assigned to the Gram-negative proteobacterial Pseudovibrio , Ruegeria , and Microbulbifer genera ( Figure 2 ). All three genera have extensive literature precedents for association with marine invertebrates and are well validated sources of bioactive natural products [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. Recently, a Pseudovibrio isolate from a Verongid sponge was reported to produce bromotyrosine alkaloid natural products [ 52 ].…”

Marine natural products

“…A combination of MS imaging and biology experiments showed that this new class of non-surfactant heptapeptides was excreted, promoting motility, and reducing biolm formation. 28 Genome mining of a Saccharothrix strain led to the identi-cation of a type II PKS BGC (sxn), that encoded several distinct subclasses of oxidoreductases, leading the researchers to hypothesise that this strain had the potential to produce novel polycyclic aromatic polyketides with unusual redox modications. Application of the One Strain Many Compounds (OSMAC) strategy using this marine bacterium and comparative metabolite analysis facilitated the discovery of 20 angucycline derivatives including six new highly oxygenated aromatic polyketides and four new glycosylated derivatives named saccharothrixins D-I 83-88 and saccharothrixins J-M 89-92, respectively.…”

“…A combination of MS imaging and biology experiments showed that this new class of non-surfactant heptapeptides was excreted, promoting motility, and reducing biofilm formation. 28…”