Taxonomy of Placospongia Gray, 1867 from Northern and Northeastern Brazil, with description of two new species (Porifera: Demospongiae: Clionaida).

The demosponge genus Placospongia includes 13 valid species, of which six occur in the Brazilian Exclusive Economic Zone. In the present study, we describe two new species of Placospongia from Northern (off the Amazon River mouth) and Northeastern Brazilian continental shelf and oceanic islands (i.e., Fernando de Noronha Archipelago), viz., Placospongia beatrizae sp. nov. and Placospongia amphinolastra sp. nov., and redescribe the holotype of Placospongia cristata Boury-Esnault, 1973, a poorly known species. In addition, we revise the Brazilian records of the allegedly cosmopolitan species P. carinata, P. melobesioides and P. intermedia, and provide new records of P. colombiensis and P. ruetzleri from Brazil. We demonstrate that P. carinata sensu Coelho & Mello-Leito and P. intermedia sensu Muricy & Moraes and Jimenez et al. belong in fact to P. ruetzleri, and that P. melobesioides sensu Mothes et al. and Gonzlez-Faras is a new species, described here as Placospongia beatrizae sp. nov. With the description of the two new species and synonymyzation of previous records, six species of Placospongia are currently known in Brazilian waters, two of which are endemic. A key to Placospongia species is also provided.

Manned submersible dives reveal a singular assemblage of Hexactinellida (Porifera) off the Amazon River mouth, Northern Brazil.

The outer shelf and upper slope region under the influence of the Amazon River mouth harbors an extensive reef system with a rich sponge fauna, but no hexactinellids were recorded in the area so far. In this work, manned submersibles were used to describe for the first time three species of Hexactinellida off the Amazon River mouth: Hyalonema (Cyliconemaoida) alucia sp. nov., Dactylocalyx pumiceus and Claviscopulia facunda. We found two morphotypes of Dactylocalyx pumiceus, suggesting that it may be a complex of cryptic species. The populations of the three species off Par State were sparse, but a large aggregation of D. pumiceus was found off Maranho State from 145 to 230 m depth. These findings indicate that hexactinellid grounds may be more common along the Northern Brazilian continental outer shelf and slope than previously thought.

Taxonomy of Geodia and Rhabdastrella from the Brazilian coast: a new species, new synonyms and redescription of Geodia tylastra (Demospongiae: Astrophorina: Geodiidae and Ancorinidae).

In this contribution we revise the type specimens of Geodia tylastra, Rhabdastrella fibrosa and Geodia corticostylifera, adding new photographs of preserved specimens, skeleton sections, and scanning electron micrographs of the spicules. We demonstrate that the three species are synonyms, with priority to the older name G. tylastra Boury-Esnault, 1973. We also show that Rhabdastrella fibrosa sensu Van Soest (2017) differs from the holotype in spicule composition and is here given a new name, Rhabdastrella vansoesti sp. nov. In addition, we describe a new species of Geodia, G. polytriaena sp. nov., and new records of G. glariosa and G. tylastra from Sergipe State, in the Northeast Brazilian coast. With the description of Geodia polytriaena sp. nov. and the synonymyzation of G. corticostylifera, 20 species of Geodia are now known in the Tropical Western Atlantic Ocean.

Genomic and in silico protein structural analyses provide insights into marine polysaccharide-degrading enzymes in the sponge-derived Pseudoalteromonas sp. PA2MD11.

Active heterotrophic metabolism is a critical metabolic role performed by sponge-associated microorganisms, but little is known about their capacity to metabolize marine polysaccharides (MPs). Here, we investigated the genome of the sponge-derived Pseudoalteromonas sp. strain PA2MD11 focusing on its macroalgal carbohydrate-degrading potential. Carbohydrate-active enzymes (CAZymes) for the depolymerization of agar and alginate were found in PA2MD11's genome, including glycoside hydrolases (GHs) and polysaccharide lyases (PLs) belonging to families GH16, GH50 and GH117, and PL6 and PL17, respectively. A gene potentially encoding a sulfatase was also identified, which may play a role in the strain's ability to consume carrageenans. The complete metabolism of agar and alginate by PA2MD11 could also be predicted and was consistent with the results obtained in physiological assays. The polysaccharide utilization locus (PUL) potentially involved in the metabolism of agarose contained mobile genetic elements from other marine Gammaproteobacteria and its unusual larger size might be due to gene duplication events. Homology modelling and structural protein analyses of the agarases, alginate lyases and sulfatase depicted clear conservation of catalytic machinery and protein folding together with suitable industrially-relevant features. Pseudoalteromonas sp. PA2MD11 is therefore a source of potential MP-degrading biocatalysts for biorefinery applications and in the preparation of pharmacologically-active oligosaccharides.

Taxonomy of some Indian and Pacific oceans Corticium, with the description of three new species from Western Australia (Porifera: Homosclerophorida).

The sponge genus Corticium has important evolutionary significance and great pharmacological potential, but its diversity remains poorly known. In this contribution we redescribe two poorly-known Indian and Pacific oceans species, viz., Corticium simplex and C. bargibanti, and describe three new species of Corticium from Western Australia. We observed for the first time the presence of rare calthrops in C. simplex, which has a wide distribution and may be a species complex. The three new species are mainly characterized by their spiculation: Corticium furcatum sp. nov. has large calthrops and exclusive candelabra with bifurcated rays in the apical actine; C. monolophum sp. nov. has large monolophose calthrops, smooth calthrops and candelabra; and C. verticillatum sp. nov. has acanthocalthrops with verticillated spines, which are exclusive to this species within the genus. The diversity of Corticium is raised to 11 species worldwide, but it still remains highly underestimated. A key to all valid species is here provided.

Metabolomic fingerprinting of Brazilian marine sponges: a case study of Plakinidae species from Fernando de Noronha Archipelago.

Marine sponges from the Plakinidae family are well known for hosting cytotoxic secondary metabolites and the Brazilian Atlantic coast and its oceanic islands have been considered as a hotspot for the discovery of new Plakinidae species. Herein, we report the chemical profile among cytotoxic extracts obtained from four species of Plakinidae, collected in Fernando de Noronha Archipelago (PE, Northeastern Brazil). Crude organic extracts of Plakinastrella microspiculifera, Plakortis angulospiculatus, Plakortis insularis, and Plakortis petrupaulensis showed strong antiproliferative effects against two different cancer cell lines (HCT-116: 86.7-100%; MCF-7: 74.9-89.5%) at 50 µg/mL, by the MTT assay. However, at a lower concentration (5 µg/mL), high variability in inhibition of cell growth was observed (HCT-116: 17.3-68.7%; MCF-7: 0.00-55.5%), even within two samples of Plakortis insularis which were collected in the west and east sides of the Archipelago. To discriminate the chemical profile, the samples were investigated by UHPLC-HRMS under positive ionization mode. The produced data was uploaded to the Global Natural Products Social Molecular Networking and organized based on spectral similarities for purposes of comparison and annotation. Compounds such as dipeptides, nucleosides and derivatives, polyketides, and thiazine alkaloids were annotated and metabolomic differences were perceived among the species. To the best of our knowledge, this is the first assessment for cytotoxic activity and chemical profiling for Plakinastrella microspiculifera, Plakortis insularis and Plakortis petrupaulensis, revealing other biotechnologically relevant members of the Plakinidae family.

High reduction of staphylococcal biofilm by aqueous extract from marine sponge-isolated Enterobacter sp.

Staphylococcus aureus and Staphylococcus epidermidis are among the most important bacterial species responsible for biofilm formation on indwelling medical devices, including orthopaedic implants. The increasing resistance to antimicrobials, partly attributed to the ability to form biofilms, is a challenge for the development of new antimicrobial agents. In this study, the cell-free supernatant obtained from sponge-associated Enterobacter strain 84.3 culture inhibited biofilm formation (>65%) and dissociated mature biofilm (>85%) formed by S. aureus and S. epidermidis strains. The culture supernatant was subjected to solvent partitioning and the aqueous extract presented a concentration-dependent antibiofilm activity for each strain with a minimum biofilm eradication concentration (MBEC) ranging from 16 to 256 µg/mL. The effect of the aqueous extract on mature S. aureus biofilm was analyzed by confocal scanning laser microscopy, showing a significant reduction of the biofilm layer as well as diminished interactions among the cells. This extract is not toxic for mammalian cells (L929 cell line). Studies targeting substances with antibiofilm activity gained significant attention in recent years due to difficult-to-treat biofilm infections. Here, sponge-associated Enterobacter 84.3 proved to be a source of substances capable of eradicating staphylococcal biofilm, with potential medical use in the future.

Not That Close to Mommy: Horizontal Transmission Seeds the Microbiome Associated with the Marine Sponge Plakina cyanorosea.

Marine sponges are excellent examples of invertebrate-microbe symbioses. In this holobiont, the partnership has elegantly evolved by either transmitting key microbial associates through the host germline and/or capturing microorganisms from the surrounding seawater. We report here on the prokaryotic microbiota during different developmental stages of Plakina cyanorosea and their surrounding environmental samples by a 16S rRNA metabarcoding approach. In comparison with their source adults, larvae housed slightly richer and more diverse microbial communities, which are structurally more related to the environmental microbiota. In addition to the thaumarchaeal Nitrosopumilus, parental sponges were broadly dominated by Alpha- and Gamma-proteobacteria, while the offspring were particularly enriched in the Vibrionales, Alteromonodales, Enterobacterales orders and the Clostridia and Bacteroidia classes. An enterobacterial operational taxonomic unit (OTU) was the dominant member of the strict core microbiota. The most abundant and unique OTUs were not significantly enriched amongst the microbiomes from host specimens included in the sponge microbiome project. In a wider context, Oscarella and Plakina are the sponge genera with higher divergence in their associated microbiota compared to their Homoscleromorpha counterparts. Our results indicate that P. cyanorosea is a low microbial abundance sponge (LMA), which appears to heavily depend on the horizontal transmission of its microbial partners that likely help the sponge host in the adaptation to its habitat.

Bacillus Strains Associated to Homoscleromorpha Sponges are Highly Active Against Multidrug Resistant Bacteria.

The search for new, powerful antimicrobials is essential to respond to the current worldwide spread of antibiotic-resistant pathogens. Sponge-associated bacteria have great potential for production of antimicrobials against resistant and multidrug resistant (MDR) pathogenic bacteria, but only few species of the Class Homoscleromorpha have been screened for these activities so far. The aim of this study was to isolate and identify sponge-associated bacteria active against antibiotic-resistant pathogens from sponges of classes Homoscleromorpha and Demospongiae. By employing five different growth conditions, a total of 239 colony-forming units were isolated and remained viable. Among these, 17 (7.1%) isolates presented antimicrobial activity against pathogenic and (multi)drug resistant bacteria including vancomycin-resistant Enterococcus faecalis, Escherichia coli, Citrobacter freundii, Klebsiella penumoniae, Staphylococcus spp. and Streptococcus spp. Bioactive bacteria belonging to genera Bacillus and Vibrio were identified at species level and the DNA fingerprint patterns showed that strains of the same genus were not clonally related. The most active strains belong to genus Bacillus and were isolated from Oscarella sp., Plakina cyanorosea and Chondrilla caribensis. Our results show for the first time that sponge-associated strains of Bacillus pumilus and Bacillus muralis have high anti-MDR activity, and that the Homoscleromorpha may be a better source of such anti-MDR active bacteria than the Demospongiae. These results suggest that marine bacteria associated to homoscleromorph sponges may be an interesting source of new antimicrobial substances with biotechnological potential to treat infections caused by antibiotic-resistant bacteria.

Peeling the Layers Away: The Genomic Characterization of Bacillus pumilus 64-1, an Isolate With Antimicrobial Activity From the Marine Sponge Plakina cyanorosea (Porifera, Homoscleromorpha).

Bacillus pumilus 64-1, a bacterial strain isolated from the marine sponge Plakina cyanorosea, which exhibits antimicrobial activity against both pathogenic and drug-resistant Gram-positive and Gram-negative bacteria. This study aimed to conduct an in-depth genomic analysis of this bioactive sponge-derived strain. The nearly complete genome of strain 64-1 consists of 3.6 Mbp (41.5% GC), which includes 3,705 coding sequences (CDS). An open pangenome was observed when limiting to the type strains of the B. pumilus group and aquatic-derived B. pumilus representatives. The genome appears to encode for at least 12 potential biosynthetic gene clusters (BGCs), including both types I and III polyketide synthases (PKS), non-ribosomal peptide synthetases (NRPS), and one NRPS-T1PKS hybrid, among others. In particular, bacilysin and other bacteriocin-coding genes were found and may be associated with the detected antimicrobial activity. Strain 64-1 also appears to possess a broad repertoire of genes encoding for plant cell wall-degrading carbohydrate-active enzymes (CAZymes). A myriad of genes which may be involved in various process required by the strain in its marine habitat, such as those encoding for osmoprotectory transport systems and the biosynthesis of compatible solutes were also present. Several heavy metal tolerance genes are also present, together with various mobile elements including a region encoding for a type III-B Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) region, four prophage segments and transposase elements. This is the first report on the genomic characterization of a cultivable bacterial member of the Plakina cyanorosea holobiont.

New records of Endectyon (Endectyon) xerampelina (Lamarck, 1814 (Demospongiae: Axinellida: Raspailiidae) from the Tropical Western Atlantic Ocean, with comments on its distribution and type locality.

The demosponge genus Endectyon is characterized by the presence of acanthostyles with recurved or clavulate spines. Two subgenera are recognized, Endectyon and Hemectyon, distinguished mainly by the acanthostyles being located only in the periphery of the axial skeleton in Endectyon, or forming the ectosomal brushes in Hemectyon. Sixteen species are known worldwide, of which only two were reported from the Western Atlantic Ocean. However, the type locality of Endectyon xerampelina is uncertain, and it could be located either in the Western Atlantic or in Australia. In the present study, we describe new records of E. xerampelina from the Brazilian coast and propose that Raspailia (R.) johnhooperi from the Guyana shelf is a junior synonym of E. xerampelina. Our results support the hypothesis that the type locality of E. xerampelina is located somewhere in the Tropical Western Atlantic Ocean and also that the species belongs to the subgenus Endectyon (Endectyon). We amended the diagnosis of the subgenus Endectyon (Endectyon) to account for the variability of acanthostyle shape in E. (E.) xerampelina, assigning greater taxonomic value to the position of the echinating megascleres than to their shape and pattern of spination.

Paraclostridium is the Main Genus of Anaerobic Bacteria Isolated from New Species of the Marine Sponge Plakina in the Brazilian Southeast Coast.

Despite the broad assessment of sponge bacterial diversity through cultivation-independent and dependent strategies, the knowledge focusing on cultivable anaerobes from this holobiont is still incipient. Plakina is a genus with the highest number of described species from the smallest of poriferan classes, Homoscleromorpha. The Brazilian Atlantic coast has been presenting itself as a hotspot for the discovery of new plakinidae species, with initial surveys just now concerning to characterize their microbiome. The current study aimed to isolate and identify strict anaerobes from recently described species of Plakina collected at the coast of Cabo Frio, RJ. Samples of four sympatric morphotypes of Plakina cyanorosea and Plakina cabofriense were collected on the coast of Cabo Frio, RJ. Using five different culture media, a total of 93 bacterial isolates were recovered, among which 60 were strict anaerobes and, ultimately, 34 remaining viable. A total of 76.5% from these strains were mostly identified as Clostridium bifermentans by mass spectrometry and 82.4% identified by 16S rRNA sequencing, almost all of them affiliated to the genus Paraclostridium, and with one isolate identified as Clostridium butyricum by both techniques. None of the anaerobic bacteria exhibited antimicrobial activity by the adopted screening test. The present work highlights not only the need for cultivation and characterization of the anaerobic microbiota from marine sponges but also adds the existing scarce knowledge of culturable bacterial communities from Homoscleromorph sponges from Brazilian coast.

Taxonomy of deep-water tetillid sponges (Porifera, Demospongiae, Spirophorina) from Brazil, with description of three new species and new characters.

Since the 19th century the deep-sea sponges from Brazil have been studied and many of them are still being discovered. This study describes five species of tetillid sponges from deep waters of the Brazilian economic exclusive zone; three are new, one is a new occurrence, and another is a known species which is here analyzed. The new species found are: Cinachyrella clavaeformis sp. nov. from the Columbia Seamount (85 m depth), Cinachyrella strongylophora sp. nov. from the Almirante Saldanha Seamount (270 m depth) and Craniella curviclada sp. nov. from slope of the Espírito Santo Basin (500 m depth). The two new species of Cinachyrella possess microacanthoxeas like those found in Cinachyrella kuekenthali (Uliczka 1929); this last species occurs in Caribbean region (4-100 m depth) and in N, NE and SE Brazil (0.2-100 m depth). The type material of Craniella corticata (Boury-Esnault 1973); from NE Brazil (75 m depth), has been found to be a synonym of Cinachyrella kuekenthali. Craniella crustocorticata van Soest 2017; from the Guyana shelf and slope (618-500 m depth), is here reported from the slope of NE and SW Brazil (400-700 m depth). A disorganized choanosomal skeleton (in Cinachyrella clavaeformis sp. nov.), strongyles (in Cinachyrella strongylophora sp. nov.) and a single-layered cortex of tangential oxeas (in Craniella crustocorticata) are new diagnostic characters that have led us to propose slight amendments in the definitions of Cinachyrella Wilson 1925 and Craniella Schmidt 1870. We discuss these and other morphological characters as well as their usefulness in Tetillidae. The diversity, distribution and bathymetry of tetillid sponges from Brazil are discussed and our knowledge of the composition of deep-sea sponges (deeper than 100 m) off Brazil is updated.

New sciaphilic plakinids (Porifera, Homoscleromorpha) from the Central-Western Pacific.

The sponge class Homoscleromorpha is a key model for the evolutionary biology of the Metazoa but its diversity remains poorly known. Here we describe six new species of the homoscleromorph family Plakinidae found in shaded habitats (submarine caves, tunnels and overhangs) of New Caledonia and Marquesas Islands, Central-Western Pacific. The new species belong to four genera: Corticium (Corticium vaceleti sp. nov.), Plakina (Plakina finispinata sp. nov.), Plakinastrella (Plakinastrella osculifera sp. nov., Plakinastrella nicoleae sp. nov. and Plakinastrella pseudolopha sp. nov.), and Plakortis (Plakortis ruetzleri sp. nov.). Plakinastrella pseudolopha sp. nov. has a novel spicule type called here 'pseudolophose spicules'. The diversity of Homoscleromorpha is raised to 50 species in the Pacific Ocean and 120 spp. worldwide.

A new cave-dwelling species of Plakina (Porifera: Homoscleromorpha) from Crete, Greece (South Aegean Sea).

Recent studies showed a high diversity of the class Homoscleromorpha (Porifera) in the North Aegean Sea. In the South Aegean Sea, however, only one species of the homoscleromorph genus Plakina, P. weinbergi, was reported so far. Here we describe a new species of Plakina from a marine cave in the South Aegean Sea (Crete Island, Greece), viz., Plakina strongylata sp. nov. The new species is white, fragile, with a highly folded surface, and its spicules are diods, triods and calthrops with rounded extremities plus mono- and dilophose diods, mono-, di- and trilophose triods, and mono-, di, tri- and tetralophose calthrops. The number of Plakina species worldwide is raised to 35, of which nine occur in the Aegean Sea.

Validation of Tethya samaaii Ribeiro & Muricy, 2011, replacement name for the sponge Tethya rubra Samaai & Gibbons, 2005 (Demospongiae, Tethyida, Tethyidae).

Tethya samaaii Ribeiro & Muricy, 2011 is a massive, irregularly globular or sub-spherical sponge with basal rooting processes or a disc-like attachment (Figure 1A). It was described from Oudekraal, on the west coast of South Africa as Tethya rubra Samaai & Gibbons, 2005 based on specimens collected during two surveys in 1996 (Samaai & Gibbons 2005). This species was later reported from Algoa Bay, on the southeast coast of South Africa by Waterworth et al. (2017).

Culturable bacterial communities associated to Brazilian Oscarella species (Porifera: Homoscleromorpha) and their antagonistic interactions.

Sponges offer an excellent model to investigate invertebrate-microorganism interactions. Furthermore, bacteria associated with marine sponges represent a rich source of bioactive metabolites. The aim of this study was to characterize the bacteria inhabiting a genus of sponges, Oscarella, and their potentiality for antimicrobial production. Bacterial isolates were recovered from different Oscarella specimens, among which 337 were phylogenetically identified. The culturable community was dominated by Proteobacteria and Firmicutes, and Vibrio was the most frequently isolated genus, followed by Shewanella. When tested for antimicrobial production, bacteria of the 12 genera isolated were capable of producing antimicrobial substances. The majority of strains were involved in antagonistic interactions and inhibitory activities were also observed against bacteria of medical importance. It was more pronounced in some isolated genera (Acinetobacter, Bacillus, Photobacterium, Shewanella and Vibrio). These findings suggest that chemical antagonism could play a significant role in shaping bacterial communities within Oscarella, a genus classified as low-microbial abundance sponge. Moreover, the identified strains may contribute to the search for new sources of antimicrobial substances, an important strategy for developing therapies to treat infections caused by multidrug-resistant bacteria. This study was the first to investigate the diversity and antagonistic activity of bacteria isolated from Oscarella spp. It highlights the biotechnological potential of sponge-associated bacteria.

Thorectinae (Porifera: Demospongiae: Dictyoceratida) from Northeastern Brazil: two new species and transfer of Scalarispongia cincta (Boury-Esnault, 1973) to the genus Thorecta Lendenfeld, 1888.

The genus Scalarispongia was raised to gather species formerly allocated in Cacospongia with rectangular fibrous skeleton of cored primary fibers and uncored secondary fibers. Species of the genus Thorecta have a similar skeletal architecture, but the presence of a dermal armour distinguishes them from Scalarispongia. Here we describe two new species of Scalarispongia from northeastern Brazil and transfer Scalarispongia cincta to Thorecta cincta. Scalarispongia tubulata sp. nov. is thick encrusting to cushion-shaped, has tubular projections with thin walls, and surface irregularly microconulose. Scalarispongia cooki sp. nov. is massive lobate, with digitiform projections and irregular surface. Thorecta cincta n. comb. is pear-shaped with conulose surface, one large apical oscule and a belt of small oscula around the body. Its skeleton is composed by a regular and granular dermal armour and by a ladder-like network of concentrically laminated primary and secondary fibers. Cacospongia amorpha and Cacospongia levis are now the only species of the genus Cacospongia known to occur in the Brazillian coast, but both records need to be reassessed. A key to species of Thorectinae from the Tropical Western Atlantic is provided.

Antibiotic resistance genes detected in the marine sponge Petromica citrina from Brazilian coast

ABSTRACT Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria.

Antibiotic resistance genes detected in the marine sponge Petromica citrina from Brazilian coast.

Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria.