Isolation and phylogenetic analysis of bacteria with antimicrobial activities from the Mediterranean sponges Aplysina aerophoba and Aplysina cavernicola

The aim of this study was to isolate bacteria with antimicrobial activities from the marine sponges Aplysina aerophoba and Aplysina cavernicola. The obtained 27 isolates could be subdivided into eight phylogenetically different clusters based on comparative sequence analysis of their 16S rDNA genes. The sponge isolates were affiliated with the low (Bacillus) and high G+C Gram-positive bacteria (Arthobacter, Micrococcus), as well as the alpha-Proteobacteria (unknown isolate) and gamma-Proteobacteria (Vibrio, Pseudoalteromonas). One novel Bacillus species was identified and two species were closely related to previously uncharacterized strains. Isolates with antimicrobial activity were numerically most abundant in the genera Pseudoalteromonas and the alpha-Proteobacteria. The sponge isolates show antimicrobial activities against Gram-positive and Gram-negative reference strains but not against the fungus Candida albicans. A general pattern was observed in that Gram-positive bacteria inhibited Gram-positive strains while Gram-negative bacteria inhibited Gram-negative isolates. Antimicrobial activities were also found against clinical isolates, i.e. multi-resistant Staphylococcus aureus and Staphylococcus epidermidis strains isolated from hospital patients. The high recovery of strains with antimicrobial activity suggests that marine sponges represent an ecological niche which harbors a hitherto largely uncharacterized microbial diversity and, concomitantly, a yet untapped metabolic potential.     

Quantitative assessment of marine sponge cells in vitro: Development of improved growth medium

Summary As sources of natural products with potential human therapeutic value, marine sponges are important subjects for cell culture studies. A critical component of any cell culture system is its growth medium. Proceeding from the hypotheses that the thawed, cryopreserved, primary cells would display detectable differential responses and that those responses could be comparatively quantified, this study has established that multiwell screening assays are useful tools for improving medium formulations in cell cultures of the marine sponge, Teichaxinella morchella. Fluorescent probe signals were correlated with known cell densities and viabilities in a 96-well format. Analysis of variance and post-test methods were applied to judge the significance of signal differences seen in a variety of medium formulations. Results from a series of experiments suggested that reducing glutamine and selenium concentrations in the standard medium would result in greater DNA, protein, and esterase activity signals. This was confirmed by the direct comparison of the standard and improved medium formulations. Significantly higher protein content and esterase activity were associated with the improved medium. DNA content was also higher, though not significantly. The result is a new medium formulation that may be more able to support cell growth and division, providing an improved cell culture system for marine sponge cell studies. The assays can be used in additional studies to further improve the in vitro conditions for marine sponge cell culture.     

海绵Phakellia fusca Schmidt的化学成分研究(Ⅳ)

用GC-MS法对中国南海扁小轴属海绵Phakellia fusca Schmidt的低极性组分进行了研究,从中分离鉴定出10种羧酸酯及16种链烃化合物。研究对扁小轴属(斧海绵亚目)海绵的化学分类具有一定意义。     

A Novel Technique for the Reattachment of Large Coral Reef Sponges

Sponges are dominant components of coral reef ecosystems, often exceeding reef-building corals in abundance. Large sponges, often more than 1 m in diameter, may be hundreds to thousands of years old. When damaged or dislodged, large sponges usually die because they are unable to reattach to the reef substratum. Because suitable methods for reattaching dislodged sponges are lacking, they are typically excluded from coral reef restoration efforts. Here we present a novel technique for the reattachment of large sponges that was tested using the Caribbean Giant barrel sponge, Xestospongia muta . Transplants of X. muta were conducted at 15- and 30-m depth off Key Largo, Florida. Despite the active hurricane season of 2005, 90% of deep and 35% of shallow transplants survived, with nearly 80% reattaching to the substratum and growing after 2.3–3 years. This technique may be generally adapted for securing large sponges in coral reef restoration efforts.     

Evolutionary emergence of synaptic nervous systems: what can we learn from the non-synaptic,nerveless Porifera?

Abstract. The Porifera represent one of the only two recent nerveless and muscleless metazoan phyla. Nevertheless, sponges provide behavioral, physiological, pharmacological, morphological, and, more recently, an increasing amount of genetic evidence for a paracrine pre-nervous integration system. Although this system might be derived, it allows us to draw conclusions, on the basis of comparative data, about the origin of the nervous system sensu stricto as found in the eumetazoan phyla. The goal of the present review is to compile recent evidence on the sponge integration systems. Based on this framework, new light is also shed on the evolutionary origin of the eumetazoan synaptic nervous systems, which can be regarded to form an evolutionary biochemical continuum with the paracrine signaling system in sponges. Thus, we can assume that the evolutionary transition from a paracrine-dominated, pre-nervous system to an electrochemically dominated, primordial nervous system resulted in part from compartmentalization effects. As intermediate evolutionary stages, regionalized synapse precursor areas might have occurred within pre-nervous cells, which foreshadowed the highly organized synaptic scaffolds present in recent nerve cells of the Eumetazoa.     

海绵生物活性物质及海绵细胞离体培养

介绍了来自海绵的生物活性物质种类、分布及其潜在的应用价值。讨论了其作为抗癌、抗病毒、抗细菌等药用的生物活性物质及其相关的海绵种属 ;强调海绵生物活性物质的商业化和临床应用所面临的“供给短缺问题”。作为解决这一问题的途径之一 ,海绵细胞离体培养是最有前景的技术。讨论了海绵细胞离体培养技术的研究现状 ,存在的问题及未来的发展趋势。对我国海域的海绵生物活性物质的研究开发现状进行总结 ,强调海绵研究对开发具有我国自主知识产权的新药、新化合物的必要性及重要性 ,并提出进行研发的可能优先领域     

Clones or clans: the genetic structure of a deep‐sea sponge,Aphrocallistes vastus,in unique sponge reefs of British Columbia,Canada

Understanding patterns of reproduction, dispersal and recruitment in deep‐sea communities is increasingly important with the need to manage resource extraction and conserve species diversity. Glass sponges are usually found in deep water (>1000 m) worldwide but form kilometre‐long reefs on the continental shelf of British Columbia and Alaska that are under threat from trawling and resource exploration. Due to their deep‐water habitat, larvae have not yet been found and the level of genetic connectivity between reefs and nonreef communities is unknown. The genetic structure of Aphrocallistes vastus, the primary reef‐building species in the Strait of Georgia (SoG) British Columbia, was studied using single nucleotide polymorphisms (SNPs). Pairwise comparisons of multilocus genotypes were used to assess whether sexual reproduction is common. Structure was examined 1) between individuals in reefs, 2) between reefs and 3) between sites in and outside the SoG. Sixty‐seven SNPs were genotyped in 91 samples from areas in and around the SoG, including four sponge reefs and nearby nonreef sites. The results show that sponge reefs are formed through sexual reproduction. Within a reef and across the SoG basin, the genetic distance between individuals does not vary with geographic distance (r = ?0.005 to 0.014), but populations within the SoG basin are genetically distinct from populations in Barkley Sound, on the west coast of Vancouver Island. Population structure was seen across all sample sites (global F_ST = 0.248), especially between SoG and non‐SoG locations (average pairwise F_ST = 0.251). Our results suggest that genetic mixing occurs across sponge reefs via larvae that disperse widely.     

A bioreactor test system to mimic the biological and mechanical environment of oral soft tissues and to evaluate substitutes for connective tissue grafts

Gingival cells of the oral connective tissue are exposed to complex mechanical forces during mastication, speech, tooth movement and orthodontic treatments. Especially during wound healing following surgical procedures, internal and external forces may occur, creating pressure upon the newly formed tissue. This clinical situation has to be considered when developing biomaterials to augment soft tissue in the oral cavity. In order to pre‐evaluate a collagen sponge intended to serve as a substitute for autogenous connective tissue grafts (CTGs), a dynamic bioreactor system was developed. Pressure and shear forces can be applied in this bioreactor in addition to a constant medium perfusion to cell‐material constructs. Three‐dimensional volume changes and stiffness of the matrices were analyzed. In addition, cell responses such as cell vitality and extracellular matrix (ECM) production were investigated. The number of metabolic active cells constantly increased under fully dynamic culture conditions. The sponges remained elastic even after mechanical forces were applied for 14 days. Analysis of collagen type I and fibronectin revealed a statistically significant accumulation of these ECM molecules (P < 0.05–0.001) when compared to static cultures. An increased expression of tenascin‐c, indicating tissue remodeling processes, was observed under dynamic conditions only. The results indicate that the tested in vitro cell culture system was able to mimic both the biological and mechanical environments of the clinical situation in a healing wound. Biotechnol. Bioeng. 2010;107: 1029–1039. © 2010 Wiley Periodicals, Inc.     

L-Lactic acid production from raw cassava starch in a circulating loop bioreactor with cells immobilized in loofa (Luffa cylindrica)

l-Lactic acid was produced from raw cassava starch, by simultaneous enzyme production, starch saccharification and fermentation in a circulating loop bioreactor with Aspergillus awamori and Lactococcus lactis spp. lactis immobilized in loofa sponge. A. awamori was immobilized directly in cylindrical loofa sponge while the L. lactis was immobilized in a loofa sponge alginate gel cube. In the loofa sponge alginate gel cube, the sponge serves as skeletal support for the gel with the cells. The alginate gel formed a hard outer layer covering the soft porous gel inside. By controlling the rate and frequency of broth circulation between the riser and downcomer columns, the riser could be maintained under aerobic condition while the downcomer was under anaerobic condition. Repeated fed-batch l-lactic acid production was performed for more than 400 h and the average lactic acid yield and productivity from raw cassava starch were 0.76 g lactic acid g^–1 starch and 1.6 g lactic acid l^–1 h^–1, respectively.     

Recipient Environment More Important than Community Composition in Determining the Success of an Experimental Sponge Transplant

Human activities have inflicted profound damage upon many ecosystems, and ecologists are now seeking effective means of restoring ecosystems to their natural state. Industrial ports and harbors are highly modified and often depauperate in native fauna. They are typically characterized by poor water quality and modified community composition, both of which may hinder attempts to reintroduce native species. Here, we conducted a field experiment to separate the effects of the recipient environment and community composition on the success of endemic sponge explants in Port Kembla Harbor, NSW, Australia. A reciprocal transplant was conducted between communities originating from six sites that varied in water quality and community composition, enabling us to assess the relative factors simultaneously. A colony of the endemic sponge Tedania anhelans was then inserted into the center of each community, and we quantified the survival, growth, and metal bioaccumulation of sponges over three months. Endemic sponges consistently performed better against resident assemblages when water quality was good. Sponges transplanted to cleaner sites had over double the survivorship and approximately three times the surface area of sponges transplanted to disturbed sites. These patterns were independent of community composition. Bioaccumulation of metals in sponges was correlated with survival; however, other factors such as turbidity may be required to explain sponge mortality at some sites. This study adds to evidence that remediation of the physical and chemical environments may be a prerequisite for biological remediation and demonstrates the value of experimental transplants in assessing restoration potential.