Investigation of biotechnological potential of sponge-associated bacteria collected in Brazilian coast.

Marine bacteria are a rich source of structurally unique natural compounds, several of which have shown a wide variety of biological activities. In this study, the metabolites present in the culture supernatants of the eight sponge-associated bacteria were extracted using ethyl acetate, and all extracts showed activity against Staphylococcus aureus. Subsequently, the extracts of the Pseudomonas fluorescens H40 and H41, and Pseudomonas aeruginosa H51 were subjected to solvent partitioning, and the active fractions were submitted to chromatographic separation. Three different active fractions were obtained, one of which was identified as diketopiperazine cyclo-(L-Leu-L-Pro). This substance was bactericidal for Staph. aureus and Ps. aeruginosa and showed cytotoxic activity against HEp-2 tumour cells. Putative gene fragments coding for the type I polyketide synthase (PKS-I) and nonribosomal peptide synthetase (NRPS) domains were PCR-amplified from five and three strains, respectively. The results suggest that sponge-associated bacteria analysed in this study may represent a potential source for production of antimicrobial substances against bacterial pathogens of medical importance.

Antifouling activity of twelve demosponges from Brazil.

Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), and Hymeniacidon heliophila (p = 0.00003). These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action.

Antifouling activity of twelve demosponges from Brazil / Atividade anti-incrustante de doze demosponjas do Brasil

Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), and Hymeniacidon heliophila (p = 0.00003). These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action.

Organismos bentônicos marinhos estão expostos constantemente à incrustação, que pode ser danosa para a maioria das espécies. Assim, a produção de metabólitos secundários com propriedades anti-incrustantes é uma vantagem ecológica importante para organismos sésseis e pode também orientar o estudo de substâncias para o desenvolvimento de tintas anti-incrustantes. O alto potencial anti-incrustante de esponjas tem sido demonstrado nos oceanos Índico e Pacífico, nos mares Mediterrâneo e Caribenho. Esponjas brasileiras permanecem pouco estudadas em relação à atividade anti-incrustante. Apenas dois artigos científicos registraram essa atividade em esponjas do Brasil. O objetivo desse estudo foi testar os extratos brutos de doze espécies de esponjas do Brasil contra a fixação do molusco Perna perna através de ensaios laboratoriais e também destacar espécies promissoras para estudos futuros. As espécies Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra e Tethya maza foram congeladas e liofilizadas logo após a coleta e posteriormente procedeu-se a extração com acetona ou diclorometano. O extrato bruto de quatro espécies inibiu significativamente a fixação de bissos: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), e Hymeniacidon heliophila (p = 0.00003). Essas espécies, especialmente, devem ser priorizadas em estudos futuros para detalhamento das substâncias envolvidas na capacidade anti-incrustante, bem como para definir sua amplitude de ação.

Three-dimensional chitin-based scaffolds from Verongida sponges (Demospongiae: Porifera). Part II: Biomimetic potential and applications.

In order to evaluate the biomedical potential of three-dimensional chitinous scaffolds of poriferan origin, chondrocyte culturing experiments were performed. It was shown for the first time that freshly isolated chondrocytes attached well to the chitin scaffold and synthesized an extracellular matrix similar to that found in other cartilage tissue engineering constructs. Chitin scaffolds also supported deposition of a proteoglycan-rich extracellular matrix of chondrocytes seeded bioconstructs in an in vivo environment. We suggest that chitin sponge scaffolds, apart from the demonstrated biomedical applications, are highly optimized structures for use as filtering systems, templates for biomineralization as well as metallization in order to produce catalysts.

Three-dimensional chitin-based scaffolds from Verongida sponges (Demospongiae: Porifera). Part I. Isolation and identification of chitin.

Marine invertebrate organisms including sponges (Porifera) not only provide an abundant source of biologically active secondary metabolites but also inspire investigations to develop biomimetic composites, scaffolds and templates for practical use in materials science, biomedicine and tissue engineering. Here, we presented a detailed study of the structural and physico-chemical properties of three-dimensional skeletal scaffolds of the marine sponges Aiolochroia crassa, Aplysina aerophoba, A. cauliformis, A. cavernicola, and A. fulva (Verongida: Demospongiae). We show that these fibrous scaffolds have a multilayered design and are made of chitin. (13)C solid-state NMR spectroscopy, NEXAFS, and IR spectroscopy as well as chitinase digestion and test were applied in order to unequivocally prove the existence of alpha-chitin in all investigated species.

Frequency distribution of XbaIG > T and HaeIIIT > C GLUT1 polymorphisms among different Brazilian ethnic groups.

GLUT is the major glucose transporter in mammalian cells. Single nucleotide polymorphisms (SNP) at GLUT1 promoter and regulatory regions have been associated to the risk of developing nephropathy in different type 1 and type 2 diabetic populations. It has been demonstrated that differences in allelic and genotypic frequencies of GLUT1 gene (SLC2A1) polymorphisms occur among different populations. Therefore, ethnic differences in distribution of GLUT1 gene polymorphisms may be an important factor in determining gene-disease association. In this study, we investigated the XbaIG > T and HaeIIIT > C polymorphisms in six different Brazilian populations: 102 individuals from Salvador population (Northern Brazil), 56 European descendants from Joinville (South Brazil), 85 Indians from Tiryió tribe (North Brazil) and 127 samples from Southern Brazil: 44 from European descendants, 42 from African descendants and 41 from Japanese descendants. Genotype frequencies from both sites did not differ significantly from those expected under the Hardy-Weinberg equilibrium. We verified that the allele frequencies of both polymorphisms were heterogeneous in these six Brazilian ethnic groups.

Marine sponges: potential sources of new antimicrobial drugs.

Sponges (phylum Porifera) are sessile marine filter feeders that have developed efficient defense mechanisms against foreign attackers such as viruses, bacteria, or eukaryotic organisms. Marine sponges are among the richest sources of pharmacologically-active chemicals from marine organisms. It is suggested that (at least) some of the bioactive secondary metabolites isolated from sponges are produced by functional enzyme clusters, which originated from the sponges and their associated microorganisms. More than 5,300 different products are known from sponges and their associated microorganisms, and more than 200 new metabolites from sponges are reported each year. As infectious microorganisms evolve and develop resistance to existing pharmaceuticals, the marine sponge provides novel leads against bacterial, viral, fungal and parasitic diseases. Many marine natural products have successfully advanced to the late stages of clinical trials, as for example ara-A (vidarabine), an anti-viral drug used against the herpes simplex encephalitis virus. This substance is in clinical use for many years. Moreover, a growing number of candidates have been selected as promising leads for extended preclinical assessment, including manzamine A (activity against malaria, tuberculosis, HIV, and others), lasonolides (antifungal activity) and psammaplin A (antibacterial activity). In this review we have surveyed the discoveries of products derived from marine sponges and associated bacteria that have shown in vivo efficacy or potent in vitro activity against infectious and parasitic diseases, including bacterial, viral, fungal and protozoan infections. Our objective was to highlight the substances that have the greatest potential to lead to clinically useful treatments.

Arenosclerins A-C and haliclonacyclamine E, new tetracyclic alkaloids from a Brazilian endemic Haplosclerid sponge Arenosclera brasiliensis.

Arenosclerins A (2), B (3), and C (4), as well as haliclonacyclamine E (1), are new tetracyclic alkylpiperidine alkaloids isolated from a new species of marine sponge belonging to the order Haplosclerida, Arenosclera brasiliensis, a species endemic to the southeastern Brazilian coast. The alkaloids were isolated as their hydrochloride salts and identified by analysis of spectroscopic data. Data obtained from (1)H-(1)H COSY, HMBC, and HSQC-TOCSY NMR experiments allowed complete assignment of the (1)H and (13)C resonances, and analysis of the NOESY and ROESY spectra showed that the only differences between 2, 3, and 4 were the relative stereochemistries of the bispiperidine ring system. Arenosclerins A-C are the first haliclonacyclamine/halicyclamine-related alkaloids with a hydroxy group in the bridging alkyl chain.