Tartrolon E, a secondary metabolite of a marine symbiotic bacterium, is a potent inhibitor of asexual and sexual Plasmodium falciparum.

Due to the spread of resistance to front-line artemisinin derivatives worldwide, there is a need for new antimalarials. Tartrolon E (TrtE), a secondary metabolite of a symbiotic bacterium of marine bivalve mollusks, is a promising antimalarial because it inhibits the growth of sexual and asexual blood stages of Plasmodium falciparum at sub-nanomolar levels. The potency of TrtE warrants further investigation into its mechanism of action, cytotoxicity, and ease with which parasites may evolve resistance to it.

A Conserved Biosynthetic Gene Cluster Is Regulated by Quorum Sensing in a Shipworm Symbiont.

Bacterial symbionts often provide critical functions for their hosts. For example, wood-boring bivalves called shipworms rely on cellulolytic endosymbionts for wood digestion. However, how the relationship between shipworms and their bacterial symbionts is formed and maintained remains unknown. Quorum sensing (QS) often plays an important role in regulating symbiotic relationships. We identified and characterized a QS system found in Teredinibacter sp. strain 2052S, a gill isolate of the wood-boring shipworm Bactronophorus cf. thoracites. We determined that 2052S produces the signal N-decanoyl-l-homoserine lactone (C10-HSL) and that this signal controls the activation of a biosynthetic gene cluster colocated in the symbiont genome that is conserved among all symbiotic Teredinibacter isolates. We subsequently identified extracellular metabolites associated with the QS regulon, including ones linked to the conserved biosynthetic gene cluster, using mass spectrometry-based molecular networking. Our results demonstrate that QS plays an important role in regulating secondary metabolism in this shipworm symbiont. This information provides a step toward deciphering the molecular details of the relationship between these symbionts and their hosts. Furthermore, because shipworm symbionts harbor vast yet underexplored biosynthetic potential, understanding how their secondary metabolism is regulated may aid future drug discovery efforts using these organisms. IMPORTANCE Bacteria play important roles as symbionts in animals ranging from invertebrates to humans. Despite this recognized importance, much is still unknown about the molecular details of how these relationships are formed and maintained. One of the proposed roles of shipworm symbionts is the production of bioactive secondary metabolites due to the immense biosynthetic potential found in shipworm symbiont genomes. Here, we report that a shipworm symbiont uses quorum sensing to coordinate activation of its extracellular secondary metabolism, including the transcriptional activation of a biosynthetic gene cluster that is conserved among many shipworm symbionts. This work is a first step toward linking quorum sensing, secondary metabolism, and symbiosis in wood-boring shipworms.

Characterisation of the enzyme transport path between shipworms and their bacterial symbionts.

BACKGROUND: Shipworms are marine xylophagus bivalve molluscs, which can live on a diet solely of wood due to their ability to produce plant cell wall-degrading enzymes. Bacterial carbohydrate-active enzymes (CAZymes), synthesised by endosymbionts living in specialised shipworm cells called bacteriocytes and located in the animal's gills, play an important role in wood digestion in shipworms. However, the main site of lignocellulose digestion within these wood-boring molluscs, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes, is the caecum, and the mechanism by which bacterial enzymes reach the distant caecum lumen has remained so far mysterious. Here, we provide a characterisation of the path through which bacterial CAZymes produced in the gills of the shipworm Lyrodus pedicellatus reach the distant caecum to contribute to the digestion of wood. RESULTS: Through a combination of transcriptomics, proteomics, X-ray microtomography, electron microscopy studies and in vitro biochemical characterisation, we show that wood-digesting enzymes produced by symbiotic bacteria are localised not only in the gills, but also in the lumen of the food groove, a stream of mucus secreted by gill cells that carries food particles trapped by filter feeding to the mouth. Bacterial CAZymes are also present in the crystalline style and in the caecum of their shipworm host, suggesting a unique pathway by which enzymes involved in a symbiotic interaction are transported to their site of action. Finally, we characterise in vitro four new bacterial glycosyl hydrolases and a lytic polysaccharide monooxygenase identified in our transcriptomic and proteomic analyses as some of the major bacterial enzymes involved in this unusual biological system. CONCLUSION: Based on our data, we propose that bacteria and their enzymes are transported from the gills along the food groove to the shipworm's mouth and digestive tract, where they aid in wood digestion.

Autochthonous production contributes to the diet of wood-boring invertebrates in temperate shallow water.

Marine wood-boring invertebrates rapidly fragment coarse woody debris in the sea. These wood borers have the ability to digest wood cellulose, but other potential food sources have been less investigated. To assess the contribution of each potential food source to the diet of wood borers, we traced seasonal and environmental changes in δ13C of shipworms cultured under the same experimental conditions and related these changes to variations in δ13C of potential food sources, i.e., wood log and particulate organic matter (POM) by using multiple linear regression models rather than the Bayesian mixing model. Based on the standardized partial regression coefficients in the model, it became clear that wood-derived organic carbon was the main carbon source for the teredinids, and POM also accounted for 37.9% of the teredinids' carbon source. Furthermore, we clarified variations in supplemental nitrogen sources for the teredinids: one species depended on both POM and wood log, whereas the other three species depended on either POM or wood log for their nitrogen source. δ13C values of another wood-boring bivalve of Martesia (Pholadidae) increase as it grows, which suggests that the bivalve switches its feeding strategy from xylophagous to filter feeding as it grows. Wood borers are known to accelerate the transfer of organic materials derived from wood logs to marine ecosystems. However, this study suggests that autochthonous production strongly contribute to the diet of marine wood borers, helping them to decompose wood logs in temperate shallow water.

Teredinibacter waterburyi sp. nov., a marine, cellulolytic endosymbiotic bacterium isolated from the gills of the wood-boring mollusc Bankia setacea (Bivalvia: Teredinidae) and emended description of the genus Teredinibacter.

A cellulolytic, aerobic, gammaproteobacterium, designated strain Bs02T, was isolated from the gills of a marine wood-boring mollusc, Bankia setacea (Bivalvia: Teredinidae). The cells are Gram-stain-negative, slightly curved motile rods (2-5×0.4-0.6 µm) that bear a single polar flagellum and are capable of heterotrophic growth in a simple mineral medium supplemented with cellulose as a sole source of carbon and energy. Cellulose, carboxymethylcellulose, xylan, cellobiose and a variety of sugars also support growth. Strain Bs02T requires combined nitrogen for growth. Temperature, pH and salinity optima (range) for growth were 20 °C (range, 10-30 °C), 8.0 (pH 6.5-8.5) and 0.5 M NaCl (range, 0.0-0.8 M), respectively when grown on 0.5 % (w/v) galactose. Strain Bs02T does not require magnesium and calcium ion concentrations reflecting the proportions found in seawater. The genome size is approximately 4.03 Mbp and the DNA G+C content of the genome is 47.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences, and on conserved protein-coding sequences, show that strain Bs02T forms a well-supported clade with Teredinibacter turnerae. Average nucleotide identity and percentage of conserved proteins differentiate strain Bs02T from Teredinibacter turnerae at threshold values exceeding those proposed to distinguish bacterial species but not genera. These results indicate that strain Bs02T represents a novel species in the previously monotypic genus Teredinibacter for which the name Teredinibacter waterburyi sp. nov. is proposed. The strain has been deposited under accession numbers ATCC TSD-120T and KCTC 62963T.

Inhibition of Biofilm Formation by Modified Oxylipins from the Shipworm Symbiont Teredinibacter turnerae.

The bioactivity-guided purification of the culture broth of the shipworm endosymbiont Teredinibacter turnerae strain 991H.S.0a.06 yielded a new fatty acid, turneroic acid (1), and two previously described oxylipins (2-3). Turneroic acid (1) is an 18-carbon fatty acid decorated by a hydroxy group and an epoxide ring. Compounds 1-3 inhibited bacterial biofilm formation in Staphylococcus epidermidis, while only 3 showed antimicrobial activity against planktonic S. epidermidis. Comparison of the bioactivity of 1-3 with structurally related compounds indicated the importance of the epoxide moiety for selective and potent biofilm inhibition.

Discovery of chemoautotrophic symbiosis in the giant shipworm Kuphus polythalamia (Bivalvia: Teredinidae) extends wooden-steps theory.

The "wooden-steps" hypothesis [Distel DL, et al. (2000) Nature 403:725-726] proposed that large chemosynthetic mussels found at deep-sea hydrothermal vents descend from much smaller species associated with sunken wood and other organic deposits, and that the endosymbionts of these progenitors made use of hydrogen sulfide from biogenic sources (e.g., decaying wood) rather than from vent fluids. Here, we show that wood has served not only as a stepping stone between habitats but also as a bridge between heterotrophic and chemoautotrophic symbiosis for the giant mud-boring bivalve Kuphus polythalamia This rare and enigmatic species, which achieves the greatest length of any extant bivalve, is the only described member of the wood-boring bivalve family Teredinidae (shipworms) that burrows in marine sediments rather than wood. We show that K. polythalamia harbors sulfur-oxidizing chemoautotrophic (thioautotrophic) bacteria instead of the cellulolytic symbionts that allow other shipworm species to consume wood as food. The characteristics of its symbionts, its phylogenetic position within Teredinidae, the reduction of its digestive system by comparison with other family members, and the loss of morphological features associated with wood digestion indicate that K. polythalamia is a chemoautotrophic bivalve descended from wood-feeding (xylotrophic) ancestors. This is an example in which a chemoautotrophic endosymbiosis arose by displacement of an ancestral heterotrophic symbiosis and a report of pure culture of a thioautotrophic endosymbiont.

Thiosocius teredinicola gen. nov., sp. nov., a sulfur-oxidizing chemolithoautotrophic endosymbiont cultivated from the gills of the giant shipworm, Kuphus polythalamius.

A chemolithoautotrophic sulfur-oxidizing, diazotrophic, facultatively heterotrophic, endosymbiotic bacterium, designated as strain 2141T, was isolated from the gills of the giant shipworm Kuphus polythalamius (Teredinidae: Bivalvia). Based on its 16S rRNA sequence, the endosymbiont falls within a clade that includes the as-yet-uncultivated thioautotrophic symbionts of a marine ciliate and hydrothermal vent gastropods, uncultivated marine sediment bacteria, and a free-living sulfur-oxidizing bacterium ODIII6, all of which belong to the Gammaproteobacteria. The endosymbiont is Gram-negative, rod-shaped and has a single polar flagellum when grown in culture. This bacterium can be grown chemolithoautotrophically on a chemically defined medium supplemented with either hydrogen sulfide, thiosulfate, tetrathionate or elemental sulfur. The closed-circular genome has a DNA G+C content of 60.1 mol% and is 4.79 Mbp in size with a large nitrogenase cluster spanning nearly 40 kbp. The diazotrophic capability was confirmed by growing the strain on chemolithoautotrophic thiosulfate-based medium without a combined source of fixed nitrogen. The bacterium is also capable of heterotrophic growth on organic acids such as acetate and propionate. The pH, temperature and salinity optima for chemolithoautotrophic growth on thiosulfate were found to be 8.5, 34 °C and 0.2 M NaCl, respectively. To our knowledge, this is the first report of pure culture of a thioautotrophic animal symbiont. The type strain of Thiosocius teredinicola is PMS-2141T.STBD.0c.01aT (=DSM 108030T).

An historical "wreck": A transcriptome assembly of the naval shipworm, Teredo navalis Linnaeus, 1978.

Historically famous for their negative impact on human-built marine wood structures, mollusc shipworms play a central ecological role in marine ecosystems. Their association with bacterial symbionts, providing cellulolytic and nitrogen-fixing activities, underscores their exceptional wood-eating and wood-boring behaviours, improving energy transfer and the recycling of essential nutrients locked in the wood cellulose. Importantly, from a molecular standpoint, a minute of omic resources are available from this lineage of Bivalvia. Here, we produced and assembled a transcriptome from the globally distributed naval shipworm, Teredo navalis (family Teredinidae). The transcriptome was obtained by sequencing the total RNA from five equidistant segments of the whole body of a T. navalis specimen. The quality of the produced assembly was accessed with several statistics, revealing a highly contiguous (1194 N50) and complete (over 90% BUSCO scores for Eukaryote and Metazoan databases) transcriptome, with nearly 38,000 predicted ORF, more than half being functionally annotated. Our findings pave the way to investigate the unique evolutionary biology of these highly modified bivalves and lay the foundation for an adequate gene annotation of a full genome sequence of the species.

Biochemical and structural characterisation of a family GH5 cellulase from endosymbiont of shipworm P. megotara.

BACKGROUND: Cellulases play a key role in the enzymatic conversion of plant cell-wall polysaccharides into simple and economically relevant sugars. Thus, the discovery of novel cellulases from exotic biological niches is of great interest as they may present properties that are valuable in the biorefining of lignocellulosic biomass. RESULTS: We have characterized a glycoside hydrolase 5 (GH5) domain of a bi-catalytic GH5-GH6 multi-domain enzyme from the unusual gill endosymbiont Teredinibacter waterburyi of the wood-digesting shipworm Psiloteredo megotara. The catalytic GH5 domain, was cloned and recombinantly produced with or without a C-terminal family 10 carbohydrate-binding module (CBM). Both variants showed hydrolytic endo-activity on soluble substrates such as ß-glucan, carboxymethylcellulose and konjac glucomannan, respectively. However, low activity was observed towards the crystalline form of cellulose. Interestingly, when co-incubated with a cellulose-active LPMO, a clear synergy was observed that boosted the overall hydrolysis of crystalline cellulose. The crystal structure of the GH5 catalytic domain was solved to 1.0 Å resolution and revealed a substrate binding cleft extension containing a putative + 3 subsite, which is uncommon in this enzyme family. The enzyme was active in a wide range of pH, temperatures and showed high tolerance for NaCl. CONCLUSIONS: This study provides significant knowledge in the discovery of new enzymes from shipworm gill endosymbionts and sheds new light on biochemical and structural characterization of cellulolytic cellulase. Study demonstrated a boost in the hydrolytic activity of cellulase on crystalline cellulose when co-incubated with cellulose-active LPMO. These findings will be relevant for the development of future enzyme cocktails that may be useful for the biotechnological conversion of lignocellulose.

Mining Small Molecules from Teredinibacter turnerae Strains Isolated from Philippine Teredinidae.

Endosymbiotic relationship has played a significant role in the evolution of marine species, allowing for the development of biochemical machinery for the synthesis of diverse metabolites. In this work, we explore the chemical space of exogenous compounds from shipworm endosymbionts using LC-MS-based metabolomics. Priority T. turnerae strains (1022X.S.1B.7A, 991H.S.0A.06B, 1675L.S.0A.01) that displayed antimicrobial activity, isolated from shipworms collected from several sites in the Philippines were cultured, and fractionated extracts were subjected for profiling using ultrahigh-performance liquid chromatography with high-resolution mass spectrometry quadrupole time-of-flight mass analyzer (UHPLC-HRMS QTOF). T. turnerae T7901 was used as a reference microorganism for dereplication analysis. Tandem MS data were analyzed through the Global Natural Products Social (GNPS) molecular networking, which resulted to 93 clusters with more than two nodes, leading to four putatively annotated clusters: lipids, lysophosphatidylethanolamines, cyclic dipeptides, and rhamnolipids. Additional clusters were also annotated through molecular networking with cross-reference to previous publications. Tartrolon D cluster with analogues, turnercyclamycins A and B; teredinibactin A, dechloroteredinibactin, and two other possible teredinibactin analogues; and oxylipin (E)-11-oxooctadec-12-enoic acid were putatively identified as described. Molecular networking also revealed two additional metabolite clusters, annotated as lyso-ornithine lipids and polyethers. Manual fragmentation analysis corroborated the putative identification generated from GNPS. However, some of the clusters remained unclassified due to the limited structural information on marine natural products in the public database. The result of this study, nonetheless, showed the diversity in the chemical space occupied by shipworm endosymbionts. This study also affirms the use of bioinformatics, molecular networking, and fragmentation mechanisms analysis as tools for the dereplication of high-throughput data to aid the prioritization of strains for further analysis.

Contrasting modes of mitochondrial genome evolution in sister taxa of wood-eating marine bivalves (Teredinidae and Xylophagaidae).

The bivalve families Teredinidae and Xylophagaidae include voracious consumers of wood in shallow and deep-water marine environments, respectively. The taxa are sister clades whose members consume wood as food with the aid of intracellular cellulolytic endosymbionts housed in their gills. This combination of adaptations is found in no other group of animals and was likely present in the common ancestor of both families. Despite these commonalities, the two families have followed dramatically different evolutionary paths with respect to anatomy, life history and distribution. Here we present 42 new mitochondrial genome sequences from Teredinidae and Xylophagaidae and show that distinct trajectories have also occurred in the evolution and organization of their mitochondrial genomes. Teredinidae display significantly greater rates of amino acid substitution but absolute conservation of protein-coding gene order, whereas Xylophagaidae display significantly less amino acid change but have undergone numerous and diverse changes in genome organization since their divergence from a common ancestor. As with many bivalves, these mitochondrial genomes encode two ribosomal RNAs, 12 protein coding genes, and 22 tRNAs; atp8 was not detected. We further show that their phylogeny, as inferred from amino acid sequences of 12 concatenated mitochondrial protein-coding genes, is largely congruent with those inferred from their nuclear genomes based on 18S and 28S ribosomal RNA sequences. Our results provide a robust phylogenetic framework to explore the tempo and mode of mitochondrial genome evolution and offer directions for future phylogenetic and taxonomic studies of wood-boring bivalves.

Discovery, activity and characterisation of an AA10 lytic polysaccharide oxygenase from the shipworm symbiont Teredinibacter turnerae.

BACKGROUND: The quest for novel enzymes for cellulosic biomass-degradation has recently been focussed on lytic polysaccharide monooxygenases (LPMOs/PMOs), Cu-containing proteins that catalyse the oxidative degradation of otherwise recalcitrant polysaccharides using O2 or H2O2 as a co-substrate. RESULTS: Although classical saprotrophic fungi and bacteria have been a rich source of lytic polysaccharide monooxygenases (LPMOs), we were interested to see if LPMOs from less evident bio-environments could be discovered and assessed for their cellulolytic activity in a biofuel context. In this regard, the marine shipworm Lyrodus pedicellatus represents an interesting source of new enzymes, since it must digest wood particles ingested during its natural tunnel boring behaviour and plays host to a symbiotic bacterium, Teredinibacter turnerae, the genome of which has revealed a multitude of enzymes dedicated to biomass deconstruction. Here, we show that T. turnerae encodes a cellulose-active AA10 LPMO. The 3D structure, at 1.4 Å resolution, along with its EPR spectrum is distinct from other AA10 polysaccharide monooxygenases insofar as it displays a "histidine-brace" catalytic apparatus with changes to the surrounding coordination sphere of the copper. Furthermore, TtAA10A possesses a second, surface accessible, Cu site 14 Å from the classical catalytic centre. Activity measurements show that the LPMO oxidises cellulose and thereby significantly augments the rate of degradation of cellulosic biomass by classical glycoside hydrolases. CONCLUSION: Shipworms are wood-boring marine molluscs that can live on a diet of lignocellulose. Bacterial symbionts of shipworms provide many of the enzymes needed for wood digestion. The shipworm symbiont T. turnerae produces one of the few LPMOs yet described from the marine environment, notably adding to the capability of shipworms to digest recalcitrant polysaccharides.

The multivariate statistical selection of fungal strains isolated from Neoteredo reynei, with the high hydrolytic potential to deconstruct cellulose.

The aim of this study was to select isolated filamentous fungi, naturally occurring in the digestive tract of Neoteredo reynei, with high potential to hydrolyze cellulolytic biomass. The selection of the fungi strains, which produce cellulases, was performed by adding carboxymethylcellulose (CMC), microcrystalline cellulose (MCC) or glucose in the media containing peptone and yeast-extract. In this case, the glucose was used as a reference standard for the growth of the mycelia. The abilities of the fungal strains, to hydrolyze cellulose, on the solid media (MCC or CMC), were evaluated. Two methods were used: the congo-red and the speed of mycelial growth. The measurements of the diameters were performed at 24 h intervals, and the speed of the mycelial growth was calculated after 72 h of cultivation. The molecular and morphological identification of the fungi were applied to the isolated strains. Statistical analysis, including ANOVA and Tukey test, and multivariate analysis were applied as tools to select the strains. Twelve strains were isolated and the results of the identification were 2 strains of Hypocrea lutea, 2 strains of Trichoderma reesei, 2 strains of Aspergillus niger; 2 genera of Aspergillus sp., 2 genera of Trichoderma sp., 1 genus of Fusarium sp. and 1 genus of Gliocadium sp. The discrimination analysis methods such as HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analysis) indicated three strains with the highest potential to hydrolyze cellulose. In this study, the selection strategy was successful, resulting in the classification of strains from the genera Trichoderma and Hypocrea. This is the first time that this kind of studying was applied to select the potential of the cellulolytic fungal strains, isolated from N. reynei, using the methods of the growth of the mycelial diameter and the statistical discrimination.

Tamilokus mabinia, a new, anatomically divergent genus and species of wood-boring bivalve from the Philippines.

Here we describe an anatomically divergent wood-boring bivalve belonging to the family Teredinidae. Specimens were collected off the coast of Mabini, Batangas, Philippines, in February 2018, from sunken driftwood at a depth of less than 2 m. A combination of characteristics differentiates these specimens from members of previously named teredinid genera and species. Most notable among these include: an enlarged cephalic hood which extends across the posterior slope of the shell valves and integrates into the posterior adductor muscle; a unique structure, which we term the 'cephalic collar', formed by protruding folds of the mantle immediately ventral to the foot and extending past the posterior margin of the valves; a large globular stomach located entirely posterior to the posterior adductor muscle and extending substantially beyond the posterior gape of the valves; an elongate crystalline style and style sac extending from the base of the foot, past the posterior adductor muscle, to the posteriorly located stomach; calcareous pallets distinct from those of described genera; a prominently flared mantle collar which extends midway along the stalk of the pallets; and, separated siphons that bear a pigmented pinstripe pattern with highly elaborate compound papillae on the incurrent siphon aperture. We used Micro-Computed Tomography (Micro-CT) to build a virtual 3D anatomical model of this organism, confirming the spatial arrangement of the structures described above. Phylogenetic analysis of the small (18S) and large (28S) nuclear rRNA gene sequences, place this bivalve within the Teredindae on a branch well differentiated from previously named genera and species. We propose the new genus and species Tamilokus mabinia to accommodate these organisms, raising the total number of genera in this economically and environmentally important family to 17. This study demonstrates the efficacy of Micro-CT for anatomical description of a systematically challenging group of bivalves whose highly derived body plans are differentiated predominantly by soft tissue adaptations rather than features of calcareous hard-parts.

Physiological traits of the symbiotic bacterium Teredinibacter turnerae isolated from the mangrove shipworm Neoteredo reynei.

Nutrition in the Teredinidae family of wood-boring mollusks is sustained by cellulolytic/nitrogen fixing symbiotic bacteria of the Teredinibacter clade. The mangrove Teredinidae Neoteredo reynei is popularly used in the treatment of infectious diseases in the north of Brazil. In the present work, the symbionts of N. reynei, which are strictly confined to the host's gills, were conclusively identified as Teredinibacter turnerae. Symbiont variants obtained in vitro were able to grow using casein as the sole carbon/nitrogen source and under reduced concentrations of NaCl. Furthermore, cellulose consumption in T. turnerae was clearly reduced under low salt concentrations. As a point of interest, we hereby report first hand that T. turnerae in fact exerts antibiotic activity. Furthermore, this activity was also affected by NaCl concentration. Finally, T. turnerae was able to inhibit the growth of Gram-negative and Gram-positive bacteria, this including strains of Sphingomonas sp., Stenotrophomonas maltophilia, Bacillus cereus and Staphylococcus sciuri. Our findings introduce new points of view on the ecology of T. turnerae, and suggest new biotechnological applications for this marine bacterium.

Physiological traits of the symbiotic bacterium Teredinibacter turnerae isolated from the mangrove shipworm Neoteredo reynei

Nutrition in the Teredinidae family of wood-boring mollusks is sustained by cellulolytic/nitrogen fixing symbiotic bacteria of the Teredinibacter clade. The mangrove Teredinidae Neoteredo reynei is popularly used in the treatment of infectious diseases in the north of Brazil. In the present work, the symbionts of N. reynei, which are strictly confined to the host's gills, were conclusively identified as Teredinibacter turnerae. Symbiont variants obtained in vitro were able to grow using casein as the sole carbon/nitrogen source and under reduced concentrations of NaCl. Furthermore, cellulose consumption in T. turnerae was clearly reduced under low salt concentrations. As a point of interest, we hereby report first hand that T. turnerae in fact exerts antibiotic activity. Furthermore, this activity was also affected by NaCl concentration. Finally, T. turnerae was able to inhibit the growth of Gram-negative and Gram-positive bacteria, this including strains of Sphingomonas sp., Stenotrophomonas maltophilia, Bacillus cereus and Staphylococcus sciuri. Our findings introduce new points of view on the ecology of T. turnerae, and suggest new biotechnological applications for this marine bacterium.