Deep-water Sponge Research Articles

Dragmacidin G, a Bioactive Bis-Indole Alkaloid from a Deep-Water Sponge of the Genus Spongosorites.

A deep-water sponge of the genus Spongosorites has yielded a bis-indole alkaloid which we have named dragmacidin G. Dragmacidin G was first reported by us in the patent literature and has recently been reported by Hitora et al. from a sponge of the genus Lipastrotheya. Dragmacidin G is the first in this series of compounds to have a pyrazine ring linking the two indole rings. It also has a rare N-(2-mercaptoethyl)-guanidine side chain. Dragmacidin G shows a broad spectrum of biological activity including inhibition of methicillin-resistant Staphylococcus aureus, Mycobacterium tuberculosis, Plasmodium falciparum, and a panel of pancreatic cancer cell lines.

Chemical and biological screening of deep-water sponges from Antarctic regions

The majority of marine natural products (MNPs) originate from tropical and temperate shallow water invertebrates, such as sponges [1]. Recent studies indicate the presence of great genetic diversity in deep-waters that may be linked to unprecedented chemistry due to evolution/adaptation to extremely harsh environmental conditions. However, only less than 2% of MNPs derive from the deep-sea organisms [2]. Antarctic ecosystems are rich in biodiversity [3] and exposed to unique environmental characteristics resulting in communities structured both by biotic interactions (e.g. predation, competition) and abiotic factors (e.g. seasonality, ice-scouring) [4], suggesting a high chemical diversity. In this work, we investigated 39 deep-water sponges collected from the Antarctic Weddell Sea and adjacent areas (depths -100 – 600 m). The freeze-dried sponge samples were extracted with water, followed by MeOH and CH2Cl2 separately. The combined organic extracts were tested for activity against cancer cells [HepG2 (liver) and HT29 (bowel) cancer cell lines], bacteria [ESKAPE panel: Enterococcus faecalis, Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli) and fungi (yeasts Candida albicans, Cryptococcus neoformans). Several Latrunculia sponge extracts displayed high anticancer activity against both cell lines (IC50 values 0.50 – 3.16 µg/ml). The organic extract of the glass sponge Rossella cf. antarctica showed moderate antibiotic activity towards MRSA and E. faecalis with IC50 values of 96 and 213 µg/ml, respectively. All extracts have undergone chemical profiling/dereplication studies by HPLC-DAD-MS and 1H NMR spectroscopy. The results of chemical and biological screening will assist in selection and activity-guided isolation of Antarctic deep-water sponge metabolites.

Leiodermatolide, a novel marine natural product, has potent cytotoxic and antimitotic activity against cancer cells, appears to affect microtubule dynamics, and exhibits antitumor activity.

Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Leiodermatolide, a polyketide macrolide with antimitotic activity isolated from a deep water sponge of the genus Leiodermatium, exhibits potent and selective cytotoxicity toward the pancreatic cancer cell lines AsPC-1, PANC-1, BxPC-3, and MIA PaCa-2, and potent cytotoxicity against skin, breast and colon cancer cell lines. Induction of apoptosis by leiodermatolide was confirmed in the AsPC-1, BxPC-3 and MIA PaCa-2 cells. Leiodermatolide induces cell cycle arrest but has no effects on in vitro polymerization or depolymerization of tubulin alone, while it enhances polymerization of tubulin containing microtubule associated proteins (MAPs). Observations through confocal microscopy show that leiodermatolide, at low concentrations, causes minimal effects on polymerization or depolymerization of the microtubule network in interphase cells, but disruption of spindle formation in mitotic cells. At higher concentrations, depolymerization of the microtubule network is observed. Visualization of the growing microtubule in HeLa cells expressing GFP-tagged plus end binding protein EB-1 showed that leiodermatolide stopped the polymerization of tubulin. These results suggest that leiodermatolide may affect tubulin dynamics without directly interacting with tubulin and hint at a unique mechanism of action. In a mouse model of metastatic pancreatic cancer, leiodermatolide exhibited significant tumor reduction when compared to gemcitabine and controls. The antitumor activities of leiodermatolide, as well as the proven utility of antimitotic compounds against cancer, make leiodermatolide an interesting compound with potential chemotherapeutic effects that may merit further research.

Sub-lethal effects of water-based drilling muds on the deep-water sponge Geodia barretti

Offshore oil and gas activities can result in the discharge of large amounts of drilling muds. While these materials have generally been regarded as non-toxic to marine organisms, recent studies have demonstrated negative impacts to suspension feeding organisms. We exposed the arctic-boreal sponge Geodia barretti to the primary particulate components of two water-based drilling muds; barite and bentonite. Sponges were exposed to barite, bentonite and a natural reference sediment at a range of total suspended solid concentrations (TSS = 0, 10, 50 or 100 mg/L) for 12 h after which we measured a suite of biomarker responses (lysosomal membrane stability, lipid peroxidation and glutathione). In addition, we compared biomarker responses, organic energy content and metal accumulation in sponges, which had been continuously or intermittently exposed to suspended barite and natural sediment for 14 d at relevant concentrations (10 and 30 mg TSS/L). Lysosomal membrane stability was reduced in the sponges exposed to barite at 50 and 100 mg TSS/L after just 12 h and at 30 mg TSS/L for both continuous and intermittent exposures over 14 d. Evidence of compromised cellular viability was accompanied by barite analysis revealing concentrations of Cu and Pb well above reference sediments and Norwegian sediment quality guidelines. Metal bioaccumulation in sponge tissues was low and the total organic energy content (determined by the elemental composition of organic tissue) was not affected. Intermittent exposures to barite resulted in less toxicity than continuous exposure to barite. Short term exposures to bentonite did not alter any biomarker responses. This is the first time that these biomarkers have been used to indicate contaminant exposure in an arctic-boreal sponge. Our results illustrate the potential toxicity of barite and the importance of assessments that reflect the ways in which these contaminants are delivered under environmentally realistic conditions.

Stable isotope signatures and distribution of deepwater sponges in Lake Baikal

To better understand the species composition and nutrition of deepwater sponges in Lake Baikal, we determined the depth, habitat, and stable isotopic signatures for deepwater sponges. All sponge specimens except one were collected at depths below the photic zone and in a variety of benthic habitats including methane seeps and hydrothermal vents. The freshwater sponge species of Lake Baikal generally occurred in aggregations (fields, carpets, and belts), and mainly on hard substrates (different types of bedrock and argillite, and bitumen). New maximum depth records were established for three species. The deepwater sponges clustered into two groups, based on their isotopic values, with members of one group assimilating organic carbon from photosynthetic sources and exhibiting δ13C values (−32 to −26.9‰) similar to those reported previously for littoral sponges. Members of the second group, distinguished by highly depleted δ13C values (−65 to −37.3‰), participate in a chemosynthetic food web. δ15N values of the deepwater sponges ranged widely (2.1–16.7‰) suggesting that they assimilate nitrogen from environmental sources and possibly from their microbial symbionts. Conservation of deepwater sponge diversity is therefore, likely dependent on the diversity of resources found in different habitats.

Fossil and modern sponge fauna of southern Australia and adjacent regions compared: interpretation, evolutionary and biogeographic significance of the late Eocene ‘soft’ sponges

The late Eocene ‘soft’ sponge fauna of southern Australia is reconstructed based on disassociated spicules and is used to interpret the paleoecology and environmental context of shallow marine communities in this region. The reconstructed sponge association was compared with coeval sponge assemblages from the Oamaru Diatomite, New Zealand, and with the modern ‘soft’ sponge fauna of southern coastal of Australia. Based on the predominance of shallow- and moderately shallow-water species, the late Eocene assemblage is interpreted to have inhabited waters depths of about 100 m. This contrast with the spicule assemblage from New Zealand, which characterized deeper waters based on the presence of numerous strictly deepwater sponge taxa, and the absence of spicules of shallow-water demosponges represented in the Australian material. The southern Australian Eocene sponge assemblages have clear Tethyan affinities evidenced by the occurrence of sponges known today from diverse regions. This distribution suggests much wider geographical ranges of some sponge taxa during the Eocene. Their present distributions may be relictual. The modern sponge fauna inhabiting southern Australian waters shows only moderate differences from these of the late Eocene. Differences are more pronounced at lower taxonomic levels (family and genus).

The use of underwater hyperspectral imaging deployed on remotely operated vehicles - methods and applications

Abstract: Currently a new underwater hyperspectral imager (UHI) have been deployed on Remotely Operated Vehicles (ROV) for a more automated identification, mapping and monitoring of bio-geo-chemical objects of interest (OOI). Sea floor maps based on UHI can be used to classify 001 based on specific optical fingerprints providing spectral upwelling radiance or reflectance with up to 1 nm spectral resolution in the visible range for each image pixel. Different habitats comprising soft bottom, deep and cold water coral reefs, sponge habitats, pipeline monitoring and kelp forest maps are examples for UHI-based mapping. Characterising material surface on man-made objects such as corrosion on pipelines and subsea structures and archaeological objects are other examples. The overall image quality and identification success of OOI can be optimized if movements of the ROV is controlled by a dynamic position (DP) system and corresponding speed, altitude, pitch, roll and yaw control. Likewise, illumination control is important to provide proper light intensity, spectral composition and illumination evenness of OOI to enhance data quality. The benefits of using UHI for seafloor habitat mapping can be evaluated by four categories of resolution. These are A) spatial resolution (image pixel size), B) spectral resolution (1-10 nm, 400-800 nm), C) radiometric resolution (dynamic range, bits per pixel), and D) temporal resolution for time-series and monitoring. These categories of resolution are discussed with respect to OOI identification and mapping using different case examples.

Unusual Deep Water sponge assemblage in South China-Witness of the end-Ordovician mass extinction.

There are few sponges known from the end-Ordovician to early-Silurian strata all over the world, and no records of sponge fossils have been found yet in China during this interval. Here we report a unique sponge assemblage spanning the interval of the end-Ordovician mass extinction from the Kaochiapien Formation (Upper Ordovician-Lower Silurian) in South China. This assemblage contains a variety of well-preserved siliceous sponges, including both Burgess Shale-type and modern type taxa. It is clear that this assemblage developed in deep water, low energy ecosystem with less competitors and more vacant niches. Its explosion may be related to the euxinic and anoxic condition as well as the noticeable transgression during the end-Ordovician mass extinction. The excellent preservation of this assemblage is probably due to the rapid burial by mud turbidites. This unusual sponge assemblage provides a link between the Burgess Shale-type deep water sponges and the modern forms. It gives an excellent insight into the deep sea palaeoecology and the macroevolution of Phanerozoic sponges, and opens a new window to investigate the marine ecosystem before and after the end-Ordovician mass extinction. It also offers potential to search for exceptional fossil biota across the Ordovician-Silurian boundary interval in China.

Synthesis of the C13–C29 fragment of leiodolide A: allylic asymmetric induction on the stereochemical course of iodolactonization

A stereocontrolled synthesis of the C13–C29 segment of leiodolide A is described. This natural product was isolated from the deep-water marine sponge Leiodermatium. A highly selective Stille cross-coupling was employed to assemble the (Z,E)-diene bearing the C15 allylic alcohol, which was followed by iodolactonization to introduce C16–C17 vicinal stereocenters. The stereochemical course of iodolactonization that is based on the solid mechanistic underpinnings arising from allylic asymmetric induction is also discussed.

Metabolic responses of the deep-water sponge Geodia barretti to suspended bottom sediment, simulated mine tailings and drill cuttings

Northeast Atlantic sponge beds are recognized as local hotspots for biodiversity and nutrient cycling. Despite their important functional role little is known about their sensitivity to effluents from the expanding hydrocarbon-, mining- and bottom trawling industry. Here, data on physiological and biological responses of the common demosponge Geodia barretti to short (4h) and long-term (50day) cyclic exposure of suspended particles are presented. The laboratory study showed that 4hour pulse exposures with crushed rock particles at 500mgl−1 caused a 50% drop in oxygen consumption but with a quick recovery to pre-exposure oxygen consumption once suspended sediment loads returned to background levels. Long-term cyclic exposure (12h each 24h) for 29days caused a permanent drop in oxygen consumption with 60% in sponges exposed to 50mgl−1 of crushed rock but with no apparent effect on the energy content of the sponge. Oxygen consumption and energy content of sponges exposed to natural bottom sediments at the same concentration remained unchanged. In conclusion, G. barretti appears to have well developed mechanisms to resist sediment stress, however, the study demonstrated that operations releasing large amounts of suspended crushed rock such as exploration drilling and submarine tailings disposal near sponge beds should be carefully planned to avoid long-term losses of benthic ecosystem functions, such as organic matter re-mineralization.

Endemic Lake Baikal sponges from deep water. 1: Potential cryptic speciation and discovery of living species known only from fossils

We revealed new deep-water species and cryptic speciation within freshwater sponges of the endemic family Lubomirskiidae (Porifera; Demospongiae; Spongillina) based on molecular and spicule morphology analyses of ITS and CO1 mtDNA. Lubomirskiidae contains a group of closely related species which are a dominant component of the benthos in Lake Baikal, the world's deepest and most ancient lake. Spicule morphology was similar between two Recent samples and species only known previously from fossils in Late Pliocene (3.2-2.8 mya) sediments. Despite the morphological similarity with the cosmopolitan family Spongillidae, molecular analysis of ITS sequences has reliably assigned these species to Lubomirskiidae. This not only indicates that species identification of freshwater fossil sponge spicules should be made with caution, but also suggests that the structure of megascleres may not be a reliable character for interpretations of paleoclimatic reconstructions for the Baikal region. Our results do not support the current classification of Lubomirskiidae into its morphologically defined genera and species, suggesting a strong discrepancy between molecular and morphological variation in Baikalian sponges. This present contribution is the first part of a study on the phylogenetic relationships of the Lake Baikal deep water sponge fauna.

First enantiospecific syntheses of marine merosesquiterpenes neopetrosiquinones a and B: evaluation of biological activity.

The first enantiospecific syntheses of neopetrosiquinones A (6) and B (7), two merosesquiterpenes isolated from the deep-water sponge Neopetrosia cf. proxima, from the labdane diterpene trans-communic acid (10) have been achieved. A key step of the synthetic sequence is the simultaneous aromatization of the C ring and the benzylic oxidation on C-7 of an advanced intermediate, mediated by the oxygen-DDQ system. The in vitro antiproliferative activities of neopetrosiquinone B (7) and of the synthetic intermediates 8 and 9 against human breast (MCF-7), lung (A-549), and colon (T-84) tumor cell lines have been assayed. The most potent was compound 9 (IC50 = 4.1 μM), which was twice as active as natural compound 7 (IC50 = 8.3 μM) against A-549 cells. In addition, the treatment with these compounds resulted in an induction of apoptosis. These findings indicate that the terpene benzoquinones reported here might be potentially useful as anticancer agents.

Puupehenol, a Potent Antioxidant Antimicrobial Meroterpenoid from a Hawaiian Deep-Water Dactylospongia sp. Sponge

From the organic extract of a deep-water Hawaiian sponge Dactylospongia sp., a new potent antioxidant and antimicrobial meroterpenoid, puupehenol (1), was isolated. The structure of 1 was determined using spectroscopic techniques ((1)H and (13)C NMR, MS, IR, UV, [α]D). The known compound puupehenone (2) was also isolated and suggested as a probable artifact of the isolation procedures. Complete unambiguous (1)H and (13)C NMR data are provided for compounds 1 and 2. Bioassays performed with 1 and 2 showed them both to be very effective antioxidants and to have antimicrobial properties.

Drivers of epibenthic megafaunal composition in the sponge grounds of the Sackville Spur, northwest Atlantic

Deep-water sponges are considered ecosystem engineers, and the presence of large aggregations of these organisms, commonly referred to as sponge grounds, is associated with enhanced biodiversity and abundance of epibenthic fauna compared to non-sponge habitat. However, the degree and magnitude to which the presence of these sponge grounds elicits large changes in composition of the associated megafaunal community remains unknown. Here we identify the external drivers of epibenthic megafaunal community composition and explore the patterns and magnitude of compositional change in the megafaunal community within the sponge grounds of the Sackville Spur, northwest Atlantic. Epibenthic megafauna were quantified from five image transects collected on the Sackville Spur in 2009 between 1080 and 1723m depth. Using Gradient Forest Modelling we found that the abundance of structure-forming sponges was the most important variable for predicting compositional patterns in the Sackville Spur megafaunal community, followed by depth, range in bottom current speed, in situ salinity, and longitude. Along the gradient in structure-forming sponge abundance, the largest turnover in megafaunal community composition occurred when the sponges reached 15 individuals m−2. Examination of the regional hydrographic conditions suggests that the dense sponge grounds of the Sackville Spur are associated with a warm, salty water mass that occurs between ~1300 and 1800m.

Benthic grazing and carbon sequestration by deep-water glass sponge reefs

Glass sponges are conspicuous members of the deep-sea fauna, but in the northeastern Pacific they form unusual reefs covering kilometers of seafloor. Individual sponges in fjords can process up to 10 m3 water d−1 osculum−1; sponge reefs must therefore process considerable volumes and could significantly affect local water properties. We measured, in situ, the flux of carbon and nitrogen through Aphrocallistes vastus, the dominant reef-building species on Fraser Ridge reef, and calculated the energetics of feeding for all reefs in the Strait of Georgia, British Columbia. Sponges removed up to 90% of bacteria from the water and released ammonium. Because of the high density of sponges, high volumetric flow rates (up to 210 ± 35 m3 m−2 d−1, mean ± standard error, 95% confidence interval (CI) 132–288 m3 m−2 d−1), and the efficient extraction of bacteria, we calculate a grazing rate of 165 ± 29 m3 m−2 d−1 (95% CI 102–228 m3 m−2 d−1) for sponge reefs, the highest benthic grazing rate of any suspension-feeding community measured to date. Reefs of A. vastus extract seven times more carbon (3.4 ± 1.4 g C m−2 d−1) than can be supported by vertical flux of total carbon alone and therefore require productive waters and steady currents to sustain their strong grazing. We calculate that modern sponge reefs in the northeastern Pacific remove 2.27 × 105 ± 0.91 × 105 kg of bacterial carbon daily, nearly an order of magnitude less than the 1.38 × 106 ± 0.55 × 106 kg removed by past sponge reefs estimated to have covered the continental shelf.

The use of DOSY in the structure elucidation of a Hawaiian deep water sponge metabolite

The use of DOSY in the structure elucidation of a Hawaiian deep water sponge metabolite

Phylogenetic diversity of microorganisms associated with the deep-water sponge Baikalospongia intermedia

The diversity of bacteria associated with deep-water sponge Baikalospongia intermedia was evaluated by sequence analysis of 16S rRNA genes from two sponge samples collected in Lake Baikal from depths of 550 and 1204 m. A total of 64 operational taxonomic units, belonging to nine bacterial phyla, Proteobacteria (classes Alphaproteobacteria,. Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria), Actinobacteria, Planctomycetes, Cloroflexi, Verrucomicrobia, Acidobacteria, Chlorobi, and Nitrospirae, including candidate phylum WS5, were identified. Phylogenetic analysis showed that the examined communities contained phylotypes exhibiting homology to uncultured bacteria from different lake ecosystems, freshwater sediments, soil and geological formations. Moreover, a number of phylotypes were relative to psychrophilic, methane-oxidizing, sulfate-reducing bacteria, and to microorganisms resistant to the influence of heavy metals. It seems likely that the unusual habitation conditions of deep-water sponges contribute to the taxonomic diversity of associated bacteria and have an influence on the presence of functionally important microorganisms in bacterial communities.

In vitro evaluation of antimicrobial activity of the freshwater sponge Ochridaspongia rotunda (Arndt, 1937)

The antimicrobial activity of five crude extracts (aqueous, methanol, ethyl acetate, acetone and methylene chloride) of the freshwater sponge Ochridaspongia rotunda (Arndt, 1937) was evaluated in vitro by using microdilution method against eight bacterial and eight fungal strains for the first time. The extracts were proven to be active in varying degrees against all the bacteria and fungi tested. O. rotunda methanol extract exhibited the highest antibacterial activity (minimum inhibitory concentration (MIC) 7.5–15.0 μg/mL and minimum bactericidal concentration 15–30 μg/mL), while its acetone extract exhibited the most promising antifungal activity (MIC 7.5–45.0 μg/mL and minimum fungicidal concentration 15–60 μg/mL). The extracts were more effective against the bacteria and fungi screened compared with the positive controls (streptomycin and ampicillin for bacteria and bifonazole and ketoconazole for fungi, respectively). According to the experimental data obtained, this deepwater sponge species may be considered as a gold mine of new antimicrobial substances with significant and broad-range activity.

Evidence of a Putative Deep Sea Specific Microbiome in Marine Sponges

The microbiota of four individual deep water sponges, Lissodendoryx diversichela, Poecillastra compressa, Inflatella pellicula, and Stelletta normani, together with surrounding seawater were analysed by pyrosequencing of a region of the 16S rRNA gene common to Bacteria and Archaea. Due to sampling constraints at depths below 700 m duplicate samples were not collected. The microbial communities of L. diversichela, P. compressa and I. pellicula were typical of low microbial abundance (LMA) sponges while S. normani had a community more typical of high microbial abundance (HMA) sponges. Analysis of the deep sea sponge microbiota revealed that the three LMA-like sponges shared a set of abundant OTUs that were distinct from those associated with sponges from shallow waters. Comparison of the pyrosequencing data with that from shallow water sponges revealed that the microbial communities of all sponges analysed have similar archaeal populations but that the bacterial populations of the deep sea sponges were distinct. Further analysis of the common and abundant OTUs from the three LMA-like sponges placed them within the groups of ammonia oxidising Archaea (Thaumarchaeota) and sulphur oxidising γ-Proteobacteria (Chromatiales). Reads from these two groups made up over 70% of all 16S rRNA genes detected from the three LMA-like sponge samples, providing evidence of a putative common microbial assemblage associated with deep sea LMA sponges.

Community structure and ecological function of deep-water sponge grounds in the Traenadypet MPA—Northern Norwegian continental shelf

Sponges within the 300km2 Trænadypet coral MPA (Marine Protected Area) were mapped using photographic techniques. Three types of sponge communities were identified. The eastern side of the central circular depression was dominated by fan-shaped Phakellia ventilabrum sponges and further characterized by Mycale lingua and Oceanapia spp. sponges. Phakellia ventilabrum abundance (0.34indm−2) was positively correlated with the number of drop stones found. The western side of the depression was dominated by Geodia barretti, G. macandrewii and G. atlantica with an estimated average abundance of 0.40indm−2 and a biomass of 2.4kgWWm−2. A third type of sponge community was found on both sides of the depression (in between the small scattered cold-water coral reefs constituting the MPA), which was characterized by Mycale lingua (0.20indm−2) and Oceanapia spp. (0.10indm−2), and which supported a high average Geodiidea biomass (1.6kgWWm−2). The two last communities were both of the boreal ostur type and seemed to form continuous belts along the 2km transects surveyed only interrupted by a few 15–30m long empty patches. Within the MPA the average overall biomass of Geodiidea sponges was 1.8kgWWm−2 and the overall sponge abundance was 1indm−2. Water pumping rates and respiration of Geodia barretti were measured, equating to 3000lkg−1 DW day−1 and 1.5μmolO2g−1DWh−1, respectively. Up-scaling this to the MPA as a whole suggests that the population of G. barretti alone could filter approximately 250millionm3 of water and consume 60t of carbon daily. This demonstrates the important ecological function of sponges as nutrient vectors and points out the MPA as an ecologically significant area that should be carefully managed and monitored.