Spheciospongia Vagabunda Research Articles

Temporal variability in tropical lagoon sponges from Mauritius (Western Indian Ocean)

Coastal lagoons are subjected to complex abiotic interactions which result to strong spatio-temporal variability of lagoon-inhabiting communities. Sponges are important components of coastal lagoons, yet their temporal variability is poorly understood. Here, we investigated the temporal variability in local distribution area (LDA), abundance (number of patches) and percentage cover of three lagoon-inhabiting sponge species: Neopetrosia chaliniformis, Amphimedon navalis and Spheciospongia vagabunda from Mauritius (Western Indian Ocean), over a 6- to 8-year period (depending on species). The correlations between two known drivers of sponge temporal patterns, sea surface temperature (SST) and chlorophyll a (Chl a) concentration, were also explored. After the survey, the total LDA and percentage cover of N. chaliniformis decreased by 40.2% and 14.6%, respectively, whereas total LDA and percentage cover of S. vagabunda increased by 135.1% and 23.3%, respectively. No significant changes were seen in the total LDA and percentage cover of A. navalis. While the abundance of N. chaliniformis and A. navalis declined over the study period, the abundance of S. vagabunda increased. SST and Chl a concentration were significantly correlated with temporal changes in abundance of all species, although correlations were species-specific. However, no significant correlations were seen between the environmental parameters and changes in sponge percentage cover, except between SST and N. chaliniformis percentage cover. Our results demonstrate that lagoon sponges show species-specific patterns in temporal variability and, while some species may potentially become locally extinct over the next few decades, if trends continue other species may become more abundant or may remain stable.

Short-term responses of tropical lagoon sponges to elevated temperature and nitrate

Sponges are often important components of coastal lagoons, however their responses to anthropogenic stressors remain poorly understood. Here, we tested the responses of three lagoon sponges, Neopetrosia exigua, Amphimedon navalis and Spheciospongia vagabunda from Mauritius (Western Indian Ocean), to nine temperature and nitrate combinations for 14 days. We found that elevated seawater temperature resulted in significant physiological responses in all species, but there was generally little negative effect of elevated nitrate. At the end of the experiment, the buoyant weight of all three species were significantly reduced, while for the two chlorophyll a-containing species, N. exigua and S. vagabunda, effective quantum yield (ΔF/Fm’) of photosystem (PS) II, photosynthetic pigment concentrations, gross photosynthetic rate and gross photosynthesis to respiration (P:R) ratio were also reduced. Dark respiration rates were higher in all three species at elevated temperature. While these lagoon sponges appeared to be impacted by elevated temperature, here, we demonstrate that these species are physiologically tolerant to excess nitrate concentrations.

ANTIMICROBIAL, ANTIVIRAL AND CYTOTOXIC ACTIVITIES OF SELECTED MARINE ORGANISMS COLLECTED FROM THE COASTAL AREAS OF MALAYSIA

Many marine organisms have developed the capability of producing unique metabolites and thus are highly likely to contain anti-infective agents. This study was conducted to investigate extracts of three seaweeds (Caulerpa racemosa, Caulerpa sertularioides, Kappaphycus alvarezii), two soft corals (Lobophytum microlobulatum, Sarcophyton auritum) and a marine sponge (Spheciospongia vagabunda) collected from Malaysian coast for antibacterial, antifungal, antiviral and cytotoxic activities. The samples were subjected to sequential solvent extraction in order to obtain hexane, chloroform, ethyl acetate, ethanol, methanol and water extracts. The antibacterial and antifungal activities were studied using a colorimetric broth microdilution method. The hexane extract of L. microlobulatum had the strongest antibacterial activity and exhibited the lowest minimum inhibitory concentration (0.04 mg/mL) and minimum bactericidal concentration (0.08 mg/mL) against Staphylococcus aureus and Bacillus cereus, respectively. For antifungal activity, the lowest MIC and minimum fungicidal concentration values were produced by the hexane extract of S. auritum against the dimorphic yeast Cryptococcus neoformans, both with 0.04 mg/mL. None of the extracts were active against the filamentous fungus Aspergillus fumigatus. Only the hexane and ethanol extracts of L. microlobulatum and the ethyl acetate extract of S. auritum exhibited strong inhibition on the cytopathic effect induced by the Chikungunya virus (a re-emerging mosquito-borne virus) with 50% effective concentrations of 14.3 ± 0.2, 124.3 ± 1.9 and 176.6 ± 9.7 μg/mL, respectively. Extracts from the two soft corals, L. microlobulatum and S. auritum possessed stronger antibacterial, antifungal and antiviral activities compared to the seaweeds and the sponge.

Cytotoxic ceramides from the Red Sea sponge Spheciospongia vagabunda

Extracts of Egyptian marine organisms from the Red Sea were screened for their anticancer activity using sulforhodamine B assay. The extract of the Red Sea sponge Spheciospongia vagabunda possessed promising anticancer activity against HepG2 (liver cancer cell line) and MCF-7 (breast cancer cell line). Isolation of three new ceramides: N-[(2S,3S,4R)-1,3,4-trihydroxytetradecan-2-yl] tridecanamide (1), (R)-2′-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxypentacosan-2-yl] octadecanamide (2) and (R,Z)-2′-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxytricosan-2-yl) nonadec-10-enamide (3) was accomplished via bioassay-guided fractionation. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. Compounds 2 and 3 displayed high potential cytotoxicity against HepG2 (IC50 24.7 and 21.3 µM, respectively) and MCF-7 (IC50 26.8 and 29.8 µM, respectively), compared with doxorubicin as control drug.

Actinokineospora spheciospongiae sp. nov., isolated from the marine sponge Spheciospongia vagabunda.

A Gram-staining-positive, aerobic organism, isolated from the Red Sea sponge Spheciospongia vagabunda was investigated to determine its taxonomic position. On the basis of results of 16S rRNA gene sequence analysis strain EG49(T) was most closely related to Actinokineospora cibodasensis and Actinokineospora baliensis (both 97.3 % similarity) and Actinokineospora diospyrosa and Actinokineospora auranticolor (both 97.0 % similarity). The 16S rRNA gene sequence similarity to all other species of the genus Actinokineospora was <97.0 %. The quinone system of strain EG49(T) contained the menaquinones MK-9(H4) (47 %), MK-9(H6) (27 %) and MK-9(H2) (15 %) in major amounts. Minor amounts of MK-7(H4) (2 %), MK-9(H0) (1 %), MK-9(H8) (3 %) and MK-10(H4) (3 %) were detected as well in addition to MK-8(H4), MK-8(H6), MK-10(H2) and MK-10(H6) (all <1 %). The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. In the polar lipid profile, diphosphatidylglycerol, phosphatidylethanolamine and hydroxyphosphatidylethanolamine were predominant. Phosphatidylinositol-mannoside, two unidentified phospholipids and two glycoglipids as well as one aminoglycolipid, one aminolipid and one unidentified lipid were found in addition. The fatty acid profile was composed of mainly iso-branched fatty acids: iso-C16 : 0, iso-C14 : 0, iso-C15 : 0 and iso-C16 : 1H. All these findings clearly supported the classification of the strain as representing a member of the genus Actinokineospora. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain EG49(T) from the most closely related species of the genus Actinokineospora. Strain EG49(T) represents a novel species of the genus Actinokineospora, for which we propose the name Actinokineospora spheciospongiae sp. nov., with strain EG49(T) ( = DSM 45935(T) = CCM 8480(T) = LMG 27700(T)) as the type strain.

New antibacterial xanthone from the marine sponge-derived Micrococcus sp. EG45

Microluside A [4 (19-para-hydroxy benzoyloxy-O-β-d-cellobiosyl), 5 (30-para-hydroxy benzoyloxy-O-β-d-glucopyranosyl) xanthone (1)] is a unique O-glycosylated disubstituted xanthone isolated from the broth culture of Micrococcus sp. EG45 cultivated from the Red Sea sponge Spheciospongia vagabunda. The structure of microluside A was determined by 1D- and 2D-NMR techniques as well as high resolution tandem mass spectrometry. The antimicrobial activity evaluation showed that 1 exhibited antibacterial potential against Enterococcus faecalis JH212 and Staphylococcus aureus NCTC 8325 with MIC values of 10 and 13μM, respectively.

Two new antioxidant actinosporin analogues from the calcium alginate beads culture of sponge-associated Actinokineospora sp. strain EG49

Marine sponge-associated actinomycetes represent an exciting new resource for the identification of new and novel natural products . Previously, we have reported the isolation and structural elucidation of actinosporins A (1) and B (2) from Actinokineospora sp. strain EG49 isolated from the marine sponge Spheciospongia vagabunda. Herein, by employing different fermentation conditions on the same microorganism, we report on the isolation and antioxidant activity of structurally related metabolites, actinosporins C (3) and D (4). The antioxidant potential of actinosporins C and D was demonstrated using the ferric reducing antioxidant power (FRAP) assay. Additionally, at 1.25μM, actinosporins C and D showed a significant antioxidant and protective capacity from the genomic damage induced by hydrogen peroxide in the human promyelocytic (HL-60) cell line.

Dereplication strategies for targeted isolation of new antitrypanosomal actinosporins A and B from a marine sponge associated-Actinokineospora sp. EG49.

High resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy were employed as complementary metabolomic tools to dereplicate the chemical profile of the new and antitrypanosomally active sponge-associated bacterium Actinokineospora sp. EG49 extract. Principal Component (PCA), hierarchical clustering (HCA), and orthogonal partial least square-discriminant analysis (OPLS-DA) were used to evaluate the HRFTMS and NMR data of crude extracts from four different fermentation approaches. Statistical analysis identified the best culture one-strain-many-compounds (OSMAC) condition and extraction procedure, which was used for the isolation of novel bioactive metabolites. As a result, two new O-glycosylated angucyclines, named actinosporins A (1) and B (2), were isolated from the broth culture of Actinokineospora sp. strain EG49, which was cultivated from the Red Sea sponge Spheciospongia vagabunda. The structures of actinosporins A and B were determined by 1D- and 2D-NMR techniques, as well as high resolution tandem mass spectrometry. Testing for antiparasitic properties showed that actinosporin A exhibited activity against Trypanosoma brucei brucei with an IC50 value of 15 µM; however no activity was detected against Leishmania major and Plasmodium falciparum, therefore suggesting its selectivity against the parasite Trypanosoma brucei brucei; the causative agent of sleeping sickness.

Metabolomic strategies in dereplication for targeted cultivation and isolation of new bioactive secondary metabolites from fungal endophytes and marine microbial symbionts

High resolution Fourier transform mass spectrometry (HRFTMS) and nuclear magnetic resonance (NMR) spectroscopy were employed as complimentary metabolomic tools to dereplicate chemical profiles of sponge-associated bacteria and fungal endophytes. The innovative strategy involved targeted cultivation and isolation of biologically active compounds. Principal Component (PCA), Hierarchical Clustering (HCA), and Orthogonal Partial Least Square-Discriminant (OPLS-DA) Analysis were used to analyze the HRFTMS and NMR data of culture extracts. The results of the statistical analysis identified and validated the best culture conditions and extraction procedure which optimized the isolation of novel bioactive metabolites. Sponge-derived actinomycetes have become a rich source of new natural products with interesting pharmacological activities. New O-glycosylated angucyclines, were isolated from the broth culture of Actinokineospora sp. strain EG49 which was cultivated from the Red Sea sponge Spheciospongia vagabunda. The structure of the compounds were determined by 1D- and 2D-NMR techniques as well as high resolution tandem mass spectrometry.

Trace metal concentrations in the tropical sponge Spheciospongia vagabunda at a sewage outfall: synchrotron X-ray imaging reveals the micron-scale distribution of accumulated metals

Major and trace elements were measured in sponges, seawater and sediment in Darwin Harbour (Australia) to test the hypothesis that metals are elevated in sponges closer to a sewage outfall compared with unimpacted sites. Seawater and sediment at the sewage discharge site contained high, but localised, concentrations of phosphorus (P), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As) and lead (Pb) compared with background sites. Metal concentrations in the sponge Spheciospongia vagabunda were highly elevated compared with other sponges and, although site specific, high metal concentrations were unrelated to the presence of sewage effluent. X-ray fluorescence microprobe imaging was used to investigate the metal distribution pattern in S. vagabunda. High Fe, Ni and Zn concentrations were either localised in circular patches (100–200 μm size) near water canals or in the pinacoderm, or scattered in spots (approximately 10 μm) throughout the tissue. This supports a microflora-mediated metal bioaccumulation hypothesis. In contrast, Co and Mn were highly dispersed and probably associated with aluminium- and iron-oxide rich sediment inclusions. Although the lack of association between sewage effluent and metal accumulation precludes the use of S. vagabunda as a biomonitor, the apparent differential mechanisms of metal accumulation warrants further investigation.

The most common sponges on the Great Barrier Reef seabed, Australia, include species new to science (Phylum Porifera)

We describe two new species amongst the most common sponges living on the seabed (inter-reef) of the Great Barrier Reef (GBR) collected during a multi-agency survey (GBR Seabed Biodiversity Project 2003–2006) of the shelf benthic biota using a trawl and dredge at 1254 sites. More than 1,200 sponge morphospecies (operational taxonomic units or OTUs) were recognised, many of which are potentially new species. This paper describes five of the most common sponges, two of which are new to science, Dercitus xanthus sp. nov. and Paracornulum fistulosum sp. nov. Taxonomic revisions of the three other most common species (Coscinoderma nardorus (Lendenfeld, 1886), Spheciospongia vagabunda (Ridley, 1884) and Xenospongia patelliformis Gray, 1858), reveal new characters not previously recorded. Extensive distribution maps are provided for these species within the GBR Marine Park. Analysis of the physical data associated with the biota revealed these species had strong preference for sand and carbonate sediments. As colonisers of the soft seabed these most prevalent species provide important habitat stabilisation, enabling succession communities to more readily establish on the seabed. This wide-scale study along the length and breadth of the GBR provides a concise and encompassing view of the distribution and diversity of the seabed benthos, and has significant implications for the conservation and management of the GBR World Heritage Area.