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Amphimedon viridis surface. SEM micrograph of a typical surface virtually free of epibiotic bacteria. Scale bar = 5 µm
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Living benthic marine organisms such as sponges and corals are frequently colonized by bacteria that may be pathogenic to them. One of the means by which they are able to combat microbial attack is by chemical defense. We tested the activity of crude organic extracts of 11 dominant Red Sea reef sponges against a panel of bacteria isolated from thei...
Citations
... Microdilution assay (Kelman et al., 2001) was used to assess the MIC of Planaxis sulcatus extract against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. For each bacterial species under consideration, a different microplate was used. ...
The study aimed at identifying novel bioactive natural compounds from intertidal marine gastropod Planaxis sulcatus (Born, 1778) Collected from the Karwar coast, West coast of India. Crude methanolic extract of intertidal marine gastropod Planaxis sulcatus was tested for preliminary zoochemical screening using standard methods to determine the presence of different chemical compounds: The crude extract was analyzed using GC-MS to identify the bioactive components. The disc diffusion method was used to conduct an antibacterial experiment. Accordingly, the inhibition zone around the disc impregnated with gastropod extract was used to test the antibacterial activity. By using the micro broth dilution technique, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined. Standard zoochemical testing of the Planaxis sulcatus whole body extract revealed the presence of steroids, alkaloids, flavonoids, glycosides, tannins, and saponins. A total of 130 chemicals were identified as the bioactive components in the extract using GC-MS. Seventeen of these compounds have antimicrobial properties while eleven of these compounds have antioxidant properties, and six of these have anticancer properties based on published literature. Some of the other compounds also suggest biological activities other than antimicrobial, antioxidant, and anticancer which indicates potential biomedical applications. The gastropod extract showed noteworthy antibacterial activity with a minimum inhibitory zone of 12 mm against Pseudomonas aeruginosa and a maximum of 30 mm against Staphylococcus aureus at 40 μg/ml concentration. The Minimum Inhibitory Concentration (MIC) was found to be 1.72 μg/ml, 1.87μg/ml, 1.99 μg/ml, and 1.87 μg/ml against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli respectively. The MIC value decreases with a higher concentration of methanol extracts than that of the pure antibiotic. As a result, Klebsiella pneumonia exhibits higher MIC values and MIC-CFU (214). The tissue extract of Planaxis sulcatus possesses bioactive compounds that have potent antibacterial effects.
... Microdilution assay (Kelman et al., 2001) was used to assess the MIC of Planaxis sulcatus extract against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. For each bacterial species under consideration, a different microplate was used. ...
The study aimed at identifying novel bioactive natural compounds from intertidal marine gastropod Planaxis sulcatus (Born, 1778) Collected from Karwar coast, West coast of India. Crude methanolic extract of intertidal marine gastropod Planaxis sulcatus was tested for preliminary zoochemical screening using standard methods to determine the presence of different chemical compounds: The crude extract was analysed using GC-MS to identify the bioactive components. The disc diffusion method was used to conduct an antibacterial experiment. Accordingly, the inhibition zone around the disc impregnated with gastropod extract was used to test the antibacterial activity. By using the micro broth dilution technique, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined. Standard zoochemical testing of the Planaxis sulcatus whole body extract revealed the presence of steroids, alkaloids, flavonoids, glycosides, tannins, and saponins. A total of 130 chemicals were identified as the bioactive components in the extract using GC-MS. Seventeen of these compounds have antimicrobial properties while eleven of these compounds have antioxidant properties, six of these have anticancer properties based on published literature. Some of the other compounds also suggest biological activities other than antimicrobial, antioxidant and anticancer which indicates potential biomedical applications. The gastropod extract showed noteworthy antibacterial activity with minimum inhibitory zone of 12 mm against Pseudomonas aeruginosa and maximum 30 mm against Staphylococcus aureus at 40 μg/ml concentration. The Minimum Inhibitory Concentration (MIC) was found to be 1.72 μg/ml, 1.87μg/ml, 1.99 μg/ml, and 1.87 μg/ml against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli respectively. The MIC value decrease with higher concentration of methanol extracts than that of the pure antibiotic. As a result, Klebsiella pneumonia exhibits higher MIC values and MIC-CFU (214). The tissue extract of Planaxis sulcatus possess bioactive compounds that have potent antibacterial effect
... Renieramycins were tested to inhibit Staphylococcus aureus, Bacillus subtilis, and Vibrio angularium but not Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Enterobacter aerogenes (Frincke and Faulkner, 1982;Kelman et al., 2001). In this study, renieramycin M did not inhibit the growth of aerobic bacteria in any treatment. ...
... In this study, renieramycin M did not inhibit the growth of aerobic bacteria in any treatment. However, antibiotic chemicals produced by sessile organisms or the symbionts were effective against specific bacteria rather than a broad spectrum (Frincke and Faulkner, 1982;Kelman et al., 2001). A number of studies elaborated more about the interaction between bacteria vs. sponge and bacteria vs. macroalgae such as anti-non-symbiotic species and antifouling (Imhoff and Trüper, 1976;Wilkinson, 1978;Lemos et al., 1985;Althoff et al., 1998;Webster and Hill, 2001;Thacker and Starnes, 2003;Armstrong et al., 2006). ...
... In some cases, microorganisms may be harmful to sessile organisms. This can be inferred by the varieties of antibiotic substances produced by sessile organisms or their symbionts (Frincke and Faulkner, 1982;Lemos et al., 1985;Kelman et al., 2001;Kubanek et al., 2002;Müller et al., 2004). ...
Allelopathy is commonly found in marine sponges. However, information on allelopathic activities of sponge extracts is limited. In this study, variations of nutritional values of Xestospongia sp. were investigated. Xestospongia did not unequally distribute its nutritional values for predatory defense. Carbon–nitrogen contents and renieramycin M concentrations were not significantly different among the areas of Xestospongia sp. (edge, inner, and outer). However, carbon–nitrogen contents and renieramycin M concentrations of Xestospongia sp. coexisting with different organisms were not significantly different. In the laboratory, bleaching and necrosis of coral nubbins were not observed in every treatment, and renieramycin M did not show any allelopathic effect on its coexisting organisms (Porites lutea and Palythoa caesia). However, renieramycin M inhibited settlement of acorn barnacle (Semibalanus balanoides) but did not inhibit the settlement of pelecypods. When testing for antimicrobial effect, renieramycin M did not inhibit the growth of aerobic bacteria in any treatments. This study provides evidence that renieramycin M found in Xestospongia was uniform; however, it can possess strong inhibitory activities against some marine organisms.
... Ethyl acetate (EA) and dichloromethane : methanol, DCM : ME (1 : 1), were used for the isolation of bioactive metabolites as previously described [10][11][12][13]. For each sponge, 10 g of fresh or thawed sample was minced using a blender and added to 150 ml of each solvent (EA and DCM : ME). e tissue and solvent mixtures of EA and DCM : ME were agitated for 72 and 48 hours, respectively, followed by filtration through a Whatman No.2 filter paper. ...
Marine invertebrates constitute a diverse group of marine organisms beneficial to humanity due to their therapeutic significance. The marine sponge species Psammaplysilla sp. 1 was collected from Philips Reef, South Africa, over a four-season period and assayed for antimicrobial potential. The physicochemical parameters of the collection site were also recorded. The sponge crude extracts’ antimicrobial activity was evaluated using an agar well diffusion assay against 5 pathogens. Phytochemical screening was conducted to identify the presence of 7 critical phytochemical groups. During the four seasons, the mean water temperature was 17.35°C ± 2.06, with autumn recording the highest (20°C) temperature. Antifungal activity was observed by Psammaplysilla sp. 1 (30 mm) against C. albicans, and this was higher than that showed by standard drugs ICZ-10 µg (15 ± 0.1 mm), FLU-15 µg (21 ± 0.2 mm), and VCZ-5 µg (17 ± 0.1 mm), respectively. Similar bioactivities were observed seasonally with Psammaplysilla sp. 1 (22 mm and 24 mm) during autumn and spring, respectively, against C. difficile while only crude extracts collected in spring showed bioactivity against C. albicans. Psammaplysilla sp. crude extracts showed broad-spectrum bioactivity against all test pathogens. DCM : ME crude extracts tested positive for the presence of 2/7 of the phytochemicals (terpenoids and flavonoids). GC-MS revealed several previously reported biologically active compounds such bicyclo[4.2.0]octa-1,3,5-trien-7-ol and phenol, 2,6-dibromo, some of which have been found in plants. This study revealed that sponge bioactivity is dependent on the season and further validated the antimicrobial potential of South African marine sponges.
... The roughness of the polyamide RO membrane after treatment was reduced, and it exhibited improved anti-fouling property during a vegetable broth solution compared to the unmodified membrane [12]. In contrast, since marine biofouling is extremely widespread and causes serious operational problems and enormous economic loss [13], many potential anti-fouling compounds are isolated from sponges, corals, and algae [14][15][16]. Increasing environmental concerns and discharge limitations have forced the scale-inhibitor chemistry to maneuver toward "green anti-scalants" that are readily biodegradable and have a minimal environmental impact [17]. ...
The anti-scaling properties of green additive seeds were used as a novel environmentally friendly on the precipitation of calcium sulfate (gypsum) scale on the reverse osmosis (RO) in desalination plants. Initial screening of many additives included: Ginger extract, Pepper extract, Lysine, and Glutamic amino acid have been carried out. The effect of additives was evaluated by measuring calcium ions renamed in the solution, and their performance that was comparable with the blank supersaturated calcium sulfate solution. The formation of the gypsum crystals has been verified using XRD and SEM analysis. It can be seen that the degree of inhibition of gypsum scale in the presence of these inhibitors is in the following order: Ginger extract ˃ Pepper extract ˃ Lysine ˃ Glutamic at different concentrations (25,50,100 ppm). A concentration of 100 ppm Ginger extract led to be superior to others with an inhibition 98.80 %. The SEM images of the collected precipitates when green inhibitors were added as a scale inhibitor, and were compared with that of the blank solution. The effect of Ginger extract (gypsum) scaling on selected reverse osmosis (RO) membrane surfaces was observed in the extent of surface scale coverage and surface crystal size among the membrane studied.
... Ethyl acetate (EA) and dichloromethane: methanol, DCM:ME (1:1) were used for the isolation of bioactive metabolites as previously described [11,12,13,14]. For each sponge, 10g of fresh or thawed sample was minced using a blender and added to 150 ml of each solvent (EA, DCM:ME). ...
Marine invertebrates constitute a diverse group of marine organisms beneficial to humankind due to their therapeutic significance. The marine sponge species Psammaplysilla sp. 1 was collected from Philips Reef, South Africa, over a four-season period and assayed for antimicrobial potential. The physicochemical parameters of the collection site were also recorded. The sponge crude extracts' antimicrobial activity was evaluated using an agar well diffusion assay against five pathogens. Phytochemical screening was conducted to identify the presence of 7 critical phytochemical groups. During the four seasons, the temperature was 17.35 o C ± 2.06, with autumn recording the highest (20 o C) temperature. Antifungal activity was observed by Psammaplysilla sp. 1 (30 mm) against C. albicans, and this was higher than that shown by standard drugs ICZ-10µg (15 ± 0.1 mm), FLU-15µg (21 ± 0.2 mm), VCZ-5µg (17 ± 0.1 mm) respectively. Similar bioactivities were observed seasonally with Psammaplysilla sp. 1 (22 mm and 24 mm) during autumn and spring, respectively, against C. difficile, while only crude extracts collected in spring showed bioactivity against C. albicans . Psammaplysilla sp crude extracts showed broad-spectrum bioactivity against all test pathogens. DCM:ME crude extracts tested positive for the presence of 2/7 of the phytochemicals (terpenoids and flavonoids). GC-MS revealed several previously reported biologically active compounds such as Bicyclo[4.2.0]octa-1,3,5-trien-7-ol and Phenol, 2,6-dibromo has been found in plants. This study revealed that sponge bioactivity is dependent on the season and further validated the antimicrobial potential of South African marine sponges.
... In a review, the structures of 143 each are provided. Numerous studies have been dedicated to the 144 separation lanthanide and actinide present in spent nuclear fuel 145 partitioning with the help of different types of extractant as well 146 as especially designed TSILs. 147 Compared to conventional organic liquids, ILs exhibit interest- 148 ing properties, as mentioned above [10]. ...
A wide range of extractant and Task Specific Ionic liquids have been studied for the removal of lanthanides and actinides from high level liquid waste (e.g. PUREX and TRUEX etc.). The studies showed that extractant/TSILs can extract lanthanides and actinides simultaneously or it can specifically target the extraction of each group separately from spent nuclear fuel. Researchers noted that lanthanides have similar oxidation states, chemical and physical properties making it difficult to separate individual lanthanides from mixtures of other lanthanides. As a result, only highly efficient and selective extractants can be used for electronic waste. Because of their unique luminescent, magnetic, electrochemical and metallurgic properties, lanthanides are highly sought after materials for numerous technological applications despite their high cost, thus making their recovery from spent nuclear fuel and electronic wastes cost effective.
In this review, we compile and describe the different methods for the removal of lanthanides and actinides. The literature review will help us better understand the design, application and performance of the vast group of extractants/ionic liquids already studied. Moreover, the information analyzed in this review will be applied in the synthesis and application of TSILs in further investigations. In addition, it also explained the physical properties of the ILs and its effects on the extraction efficiency of system.
... Ethyl acetate (EA) and dichloromethane : methanol (DCM : ME, 1 : 1) were used for the isolation of bioactive metabolites as previously described [12,13]. For each sponge, 10 g of fresh or thawed sample was minced using a blender and added to 150 ml of each solvent (EA, DCM : ME). ...
Scientists have continuously searched for novel bioactive compounds to overcome the inherent problems associated with drug resistance, the evolution of unknown diseases, and the toxicity of currently used compounds. The ocean has been considered a rich source of compounds that possess unique chemical structures and novel biological capabilities. Biologically active molecules isolated from marine flora and fauna have shown significant advancement over the past century in the pharmaceutical industry. Marine natural products (MNPs) have been used as nanomedicine, cosmetics, wound healing, antimicrobial agents, anticancer agents, and anti-inflammatory agents. The physicochemical parameters of the collection site were also recorded. This study’s marine sponge species were collected from Phillip’s Reef, South Africa, at 12 m during the spring season. Ethyl acetate (EA) and dichloromethane : methanol (DCM : ME, 1 : 1) were used as extraction solvents. Crude extracts of the marine sponges were tested against MRSA, P. aeruginosa, C. difficile, A. fumigatus, and C. albicans. Phytochemical screening was conducted to identify seven critical phytochemical groups. A pH reading of 8.01 and a temperature of 15.45°C were recorded at the sampling site. Clathria sp. 1 and Tedania (Tedania) stylonychaeta EA crude extracts showed bioactivity against all five test pathogens. The DCM : ME crude extract of Clathria sp. 1 was the only bioactive crude extract from DCM : ME extracts. This crude extract was only bioactive against C. albicans as no activity was observed against the other four pathogens. EA crude extracts of Clathria sp. 1 yielded more significant inhibition zones against both fungal pathogens. These EA crude extracts performed better than fluconazole as inhibition zones of at 24 mg/ml, at 19 mg/ml, at 14.4 mg/ml, at 9.6 mg/ml, and at 7.2 mg/ml were recorded. Clathria sp. 1 crude extracts exhibited higher inhibition zones compared to Tedania (Tedania) stylonychaeta. The antibiotic imipenem ( at 10 μg) and ciprofloxacin ( at 5 μg) exhibited higher zones of inhibition than EA crude extracts of Tedania (Tedania) stylonychaeta at all test concentrations. In this study, Clathria sp. 1 was observed to have broad-spectrum bioactivity as EA crude extracts were bioactive against MRSA, P. aeruginosa, C. difficile, A. fumigatus, and C. albicans. In addition to this, the EA crude extract of Clathria sp. 1 was bacteriostatic (9.6 mg/ml). Clathria sp. 1 DCM : ME crude extract only tested positive for the presence of terpenoids. In contrast, EA crude extracts did not test positive for the existence of any of the seven phytochemicals. Our study has revealed that Tedania (Tedania) stylonychaeta and Clathria sp. 1 sponge species collected from Phillip’s Reef in South Africa can produce bioactive compounds useful against bacterial and fungal species.
1. Introduction
The ocean is a rich source of compounds possessing novel structures and biological activities. Biologically active molecules isolated from marine flora and fauna have applications in pharmaceuticals, cosmetics, nutritional supplements, enzymes, molecular probes, fine chemicals, and agrochemicals. Important secondary metabolites, including antibiotics, herbicides, and growth-promoting substances, are produced by several members of marine microorganisms [1]. Scientists have continuously searched for novel bioactive compounds to overcome drug resistance’s inherent problems, the toxicity of currently used compounds, and the increased incidence of severe diseases, which have been reported to cause cancer, antimicrobial resistance, and neurodegenerative pathologies which have led to the need for the discovery and development of novel medicines.
Sponges are spineless animals belonging to the phylum Porifera and serve as the most primitive multicellular animals. Marine sponges are soft-bodied, sessile, and filter feeders by assembling small particulate matter from seawater rising through their bodies [2]. Marine organisms represent approximately 80% of the world’s biota [3] and are a source of unique natural products ranging from food, fragrances, pigments, and insecticides. Approximately 10,000 pharmacologically bioactive compounds have been extracted from marine invertebrates. Such invertebrates are tunicates, sponges, soft corals, sea hares, nudibranchs, bryozoans, and sea slugs [4]. As of 2003, amongst marine organisms, the largest number of secondary metabolites isolated since 1965 have come from sponges [5], and they have been the primary source of biologically active molecules.
The first marine biodiscovery program was centred at a South African university. This program, a scuba collection of approximately a dozen marine sponges, was initiated by a Rhodes University ichthyologist team from a subtidal reef in the Tsitsikamma National Park, situated on the Southern Cape coast of South Africa during the spring of 1990 [6]. It was observed that sponge metabolites’ primary biological activities were to kill or prevent the growth of microbial pathogens [7]. The secondary metabolites derived from these marine invertebrates have shown antibiotic, antiparasitic, antiviral, and anticancer activities [8]. About 5000 compounds to date were isolated from sponges worldwide, accounting for about 30% of all compounds obtained from the marine environment thus far. Approximately more than two hundred newly discovered bioactive products derived from sponges are reported yearly since the last decade [9]. It is hypothesized that sponges have used different metabolic pathways to produce diverse and unique bioactive compounds to support the marine sponges’ survival. These chemicals include defence agents against microbial infection and agents used in the competition for space in the crowded marine reef environment [10]. Several medications derived from sponges are available in the market, and others are in clinical trials (Eribulin Mesylate, Cytarabine, and Vidarabine) [11]. Generally, marine invertebrates have been mostly researched for neurophysiological and anticancer properties rather than antimicrobial potential. Therefore, there is a lack of data on the antibacterial and antifungal activity of marine invertebrates’ compounds. Most of the research done in South Africa focuses on the isolation of marine-associated microbiota for antimicrobial compound screening. Given South Africa’s rich biodiversity of marine invertebrates across its far-stretching coastline, this was a perfect opportunity for marine natural products to be explored from two marine sponge species indigenous to the Southern East Coastline of South Africa.
2. Materials and Methods
2.1. Sample Collection and Taxonomical Identification
Samples were collected from Phillip’s Reef in Algoa bay with coordinates 33°5837.2S 25°4022.8E, Port Elizabeth, Eastern Cape Province of South Africa (Figure 1).
... The structure of amphitoxin differs from that of halitoxin in that it has an additional carbon-carbon double bond in the alkyl chain that joins the pyridinium rings. Their similar structures make separation difficult and all attempts to separate this mixture were unsuccessful [46,[53][54][55]. Subfraction R4H2 displayed higher antibacterial activity than fraction R4, yielding a MIC value of 2-4 mg/L for different strains of A. baumannii, K. pneumoniae, and P. aeruginosa and a MIC value of 1 mg/L for both strains of S. aureus (Tables 2 and 3). ...
... Regarding antibacterial activity, these compounds are able to inhibit bacterial attachment of Vibrio harveyi, a motile marine bacterium, but have not been reported to inhibit growth of the species [57]. Furthermore, these compounds have also been reported to show antibacterial activity against marine environmental isolates (MICs 4-256 mg/L) [55], as well as antifungal activity [47]. However, the antibacterial activity of halitoxins and amphitoxins detected in this study against the main multidrug-resistant human pathogens had not yet previously been observed. ...
A total of 51 sponges (Porifera) and 13 ascidians (Chordata) were collected on the coast of the Yucatan Peninsula (Mexico) and extracted with organic solvents. The resulting extracts were screened for antibacterial activity against four multidrug-resistant (MDR) bacterial pathogens: the Gram-negative Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentrations (MICs) of the organic extracts of each marine organism were determined using a broth microdilution assay. Extracts of eight of the species, in particular the Agelas citrina and Haliclona (Rhizoniera) curacaoensis, displayed activity against some of the pathogens tested. Some of the extracts showed similar MIC values to known antibiotics such as penicillins and aminoglycosides. This study is the first to carry out antimicrobial screening of extracts of marine sponges and ascidians collected from the Yucatan Peninsula. Bioassay-guided fractionation of the active extracts from the sponges Amphimedon compressa and A. citrina displayed, as a preliminary result, that an inseparable mixture of halitoxins and amphitoxins and (-)-agelasine B, respectively, are the major compounds responsible for their corresponding antibacterial activities. This is the first report of the antimicrobial activity of halitoxins and amphitoxins against major multidrug-resistant human pathogens. The promising antibacterial activities detected in this study indicate the coast of Yucatan Peninsula as a potential source of a great variety of marine organisms worthy of further research.
... Several studies revealed the production of a variety of bioactive compounds by symbionts including those applied for quorum sensing (QS) and antimicrobial defense, which often form the basis for pathogen defense systems (Bewley et al., 1996;Paul and Puglisi, 2004;Hentschel et al., 2006;Taylor et al., 2007;Thomas et al., 2016). The antimicrobial defense was likely one of the key elements in the evolutionary selectivity of sponge-associated microbial communities and thus their resilience against pathogens (Kelman et al., 2001;Rohde et al., 2012). In this context, QS may play an important role in shaping microbial community composition and interactions, and controlling the biological activity of the sponge microbiota. ...
Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that the long-term aquarium cultured sponge H. cnidata is tightly associated with a typical sponge bacterial microbiota and (2) that the symbiotic Bacteria sustain bioactivity under harmful environmental conditions to facilitate holobiont survival by preventing pathogen invasion. Microscopic and phylogenetic analyses of the bacterial microbiota revealed that H. cnidata represents a high microbial abundance (HMA) sponge with a temporally stable bacterial community that significantly shifts with changing aquarium conditions. A 4-week incubation experiment was performed in small closed aquarium systems with antibiotic and/or light exclusion treatments to reduce the total bacterial and photosynthetically active sponge-associated microbiota to a treatment-specific resilient community. While the holobiont was severely affected by the experimental treatment (i.e., bleaching of the sponge, reduced bacterial abundance, shifted bacterial community composition), the biological defense and bacterial community interactions (i.e., quorum sensing activity) remained intact. 16S rRNA gene amplicon sequencing revealed a resilient community of 105 bacterial taxa, which remained in the treated sponges. These 105 taxa accounted for a relative abundance of 72–83% of the bacterial sponge microbiota of non-treated sponge fragments that have been cultured under the same conditions. We conclude that a sponge-specific resilient community stays biologically active under harmful environmental conditions, facilitating the resilience of the holobiont. In H. cnidata, bacteria are located in bacteriocytes, which may have contributed to the observed phenomenon.
