Padina Gymnospora Research Articles

A comparison of nutritional value of underexploited edible seaweeds with recommended dietary allowances

The present study evaluated the nutritional composition of under-exploited edible seaweeds and its comparison with recommended dietary allowances (RDA) of pregnant women. Some under-exploited seaweeds were identified such as Acanthophora spicifera, Gracilaria edulis, Padina gymnospora, Ulva fasciata and Enteromorpha flexuosa were not utilized directly as a food, thus evaluated their wholesome nutrients for food application. Results showed that micronutrients were found to be high in selected seaweeds such as iron in the range of 14.8–72 mg/100 g, iodine 38.8–72.2 mg/100 g, and calcium 410–870 mg/100 g. The essential aminoacids were between 189.2 and 306 mg/g, essential fatty acid like arachidonic acid was 0.80% and 0.59% of linoleic acid, monounsaturated fatty acid were 3.05–14.08% in U. fasiciata. Heavy metals were within the tolerable limit, mercury was found 0.030 ppm A. spicifera and not detected in other species, arsenic 0.012–0.076 ppm, cadmium content ranges between 0.012 and 0.081 ppm in all species. These nutrients meet more than 70% of macro and micronutrients in precise combination of RDA suggested for pregnant women. Therefore, seaweed would be better alternative food source to meet food security challenges.

Evaluation of in vivo sub-chronic and heavy metal toxicity of under-exploited seaweeds for food application

Seaweeds are known to be rich source of micronutrients and bioactive compounds. The main objective of this study was to find the toxicological evaluation and heavy metal accumulation of five under-exploited edible seaweeds in animal model followed by dosage determination for regular consumption as a food by humans and food application. Some under-exploited seaweeds like Acanthophora spicifera, Gracilaria edulis, Padina gymnospora, Ulva fasciata and Enteromorphoa flexuosa were selected forthis study. The ED50 study was conducted in Wistar strain rats for 90 days with single dose administration of seaweed extract of 2000 mg/kg/BW. At the end of 90th day rats were euthanized, serum of the rats examined for biochemical, haematological, liver enzymes, and vital organs were dissected out for heavy metal analysis and urine samples collected intermediary to analyse electrolyte minerals. Result showed that no-observed adverse effect level (NOEL) on five seaweeds, did not cause any death and no significant variation in biochemical and haematological parameters, the values were found within standard values. Locomotor activity suggests normal action, organ necropsy showed no histopathology lesions, regular cell alignment in the tissue cross section. Heavy metals like arsenic, lead were found in trace amount and no mercury accumulation found in kidney, liver and brain of rats. Therefore, these five seaweeds were safe for human consumption and also for food product developement.

Community structure and functional traits of mollusks associated with coastal reef macroalgae in Northeastern Brazil

AbstractThis study investigated the community structure and functional traits of the mollusk fauna associated with macroalgae with different thallus morphologies in a reef environment in Northeastern Brazil. A total of 15 individuals of each species of macroalgae adhered to natural substrate and 15 individuals of Padina gymnospora detached from the substrate were collected. The structural complexity of algal habitats was measured and the associated malacofauna screened and identified. All three macroalgae differed significantly in the complexity of their habitat, with Sargassum polyceratium being the most complex. A total of 823 specimens of mollusks belonging to 22 species and 11 families were recorded, of which Columbellidae was the most represented with six species. The functional trait “size” revealed that micromollusks smaller than 10 millimeters were predominant in the community; however, individuals of larger sizes (up to 24.54 millimeters) belonging to young stages of other species were also present. Eight functional trophic groups were identified, of which “carnivorous” stood out with seven species. Six functional groups of microhabitats were identified, with intra‐specific variation in habitats, while habitat expansion was documented for species not yet recorded in association with macroalgae. The structure of the molluskan community differed among the three algae species with the greatest richness, abundance, and diversity of mollusks and functional traits occurring with S. polyceratium. Community structure differed between algae adhered to natural substrate and detached algae, with the latter having lower mollusk richness and diversity, but with greater abundance of some species that remained on algal fronds after release from the reef environment. This study reinforces the importance of algal habitat for marine invertebrate fauna, especially for micromollusks that spend their entire life cycle, or part of it, in association with macroalgae.

Amyloid-β induced neuropathological actions are suppressed by Padina gymnospora (Phaeophyceae) and its active constituent α-bisabolol in Neuro2a cells and transgenic Caenorhabditis elegans Alzheimer's model

The inhibition of Aβ peptide development and aggregation is a hopeful curative approach for the discovery of disease modifying drugs for Alzheimer's disease (AD) treatment. Recent research mainly focuses on the discovery of drugs from marine setting due to their immense therapeutic potential. The present study aims to evaluate the brown macroalga Padina gymnospora and its active constituent α-bisabolol against Aβ25-35 induced neurotoxicity in Neuro2a cells and transgenic Caenorhabditis elegans (CL2006 and CL4176). The results of the in vitro study revealed that the acetone extract of P. gymnospora (ACTPG) and its active constituent α-bisabolol restores the Aβ25-35 induced alteration in the oxidation of intracellular protein and lipids. In addition, ACTPG and α-bisabolol inhibited cholinesterase and β-secretase activity in Neuro2a cells. Moreover, the intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) production was reduced by ACTPG and α-bisabolol in Neuro2a cells. The decrease in the expression level of apoptotic proteins such as Bax and caspase-3 in ACTPG and α-bisabolol treated group indicates that the seaweed and its bioactive compound have anti-apoptotic property. Further, the in vivo study revealed that the ACTPG and α-bisabolol exerts neuroprotective effect against Aβ induced proteotoxicity in transgenic C. elegans strains of AD. Moreover it altered the Aβ mediated pathways, lifespan, macromolecular damage and down regulated the AD related gene expression of ace-1, hsp-4 and Aβ, thereby preventing Aβ synthesis. Overall, the outcome of the study signifies the neuroprotective effect of ACTPG and α-bisabolol against Aβ mediated AD pathology.

Nursery culture of wild and hatchery-produced juveniles of the West Indian top shell, Cittarium pica, fed microalgal and artificial biofilms

Cittarium pica is an overexploited Caribbean top shell that is being produced at an experimental level by aquaculture for conservation purposes. To optimise nursery culture, the growth and survival of wild and hatchery-produced juveniles were assessed after feeding with different biofilm diets. The following three diets were tested over a 6-month period: (1) a microalgal biofilm of Nitzschia sp. and Tetraselmis chuii; (2) an artificial biofilm of dry seaweeds, Padina gymnospora and Laurencia obtusa, and the cyanobacterium Spirulina sp.; and (3) a mix of the microalgal and artificial biofilms. The biofilms were prepared and supplied on folded PVC plates, and treatments were administered in triplicated 10-L aquaria with down-welling systems at 25 ± 1 °C and a salinity of 36.5 ± 0.5 ppt. Higher growth rates were obtained in juveniles fed diets containing artificial biofilms, which had high protein and energy contents, whereas survival rates were higher in juveniles fed the mixed diet. The relatively high growth and survival values suggest that the nursery culture can be improved by feeding with the mix of microalgal and artificial biofilms and that the temporary translocation of wild juveniles to nursery conditions can be a tool for population enhancement.

Effects of macroalgal host identity and predation on an amphipod assemblage from a subtropical rocky shore

Seaweeds play a key role in the rocky-shore fauna by providing shelter and food for many invertebrate species, which in turn compose the diet of benthic and pelagic predators. This study investigated the effect of the macroalgal host species on an assemblage of associated amphipods, and tested if the host mediates the vulnerability of amphipods to predation. The association of amphipods with the macroalgal hosts Dichotomaria marginata, Padina gymnospora, and Sargassum filipendula was evaluated seasonally for 1 year on a subtropical rocky shore on the southeastern coast of Brazil. The density of amphipods did not vary with season or host. However, the composition of amphipod species was sensitive to the host macroalgal species and varied temporally. A field experiment showed no clear effect of predation on the amphipod assemblage. Also, predation did not explain the spatial or temporal variation of the amphipod assemblage. Our results indicate that the identity of the macroalgal host drove the composition of the associated amphipods, while predation may have a minor role. Therefore, the loss of habitat-forming organisms such as seaweeds is expected to have drastic consequences for the composition of associated fauna, and consequently on the flow of matter and energy in coastal ecosystems.

Testing the importance of predation refuge vs. food quality in determining the use of macroalgal hosts by a generalist marine mesograzer

Bottom-up (e.g. resource quality) and top-down (e.g. predation) factors have strong effects on the fitness and distribution of small herbivores. Herein, we investigated how food quality and refuge offered by macroalgal hosts influence the distribution of a mesograzer. We used the herbivorous amphipod Cymadusa filosa and seasonally evaluated its association with the macroalgal hosts Sargassum filipendula, Padina gymnospora, and Dichotomaria marginata on a subtropical rocky shore from the Brazilian southeastern coast. Feeding experiments were conducted to test the food value of hosts, while predation experiments in the field and laboratory were performed to investigate the refuge value of the macroalgae. Cymadusa occurred on Padina in a density greater than that observed on Dichotomaria and Sargassum, while Dichotomaria harbored more amphipods than Sargassum. Adults of Cymadusa showed a higher consumption of Padina and Sargassum in both choice and no-choice feeding experiments and juveniles had greater growth and reproductive potential when feeding on such macroalgae. In the predation experiment in the field, Padina was a better refuge for Cymadusa than Sargassum. However, no difference in refuge value among hosts was observed in the laboratory assays. The distribution of Cymadusa was explained by a balance between food and refuge values of hosts, with higher abundances being observed in the high-quality food alga that provides refuge against predators (e.g. Padina), while fewer individuals occurred in other high-quality food that was less suitable as refuge (e.g. Sargassum). Therefore, predation may be more of a determinant for distribution of that mesograzer than resource quality.

Adsorption of Cd2+ and Cr3+ ions from aqueous solutions by using residue of Padina gymnospora waste as promising low-cost adsorbent

Recently, a great attention has been given for applying a low-cost and effective adsorbents instead of expensive and dangerous chemical materials as a promising approach to treat wastewater. In this work, residue powder of brown macroalga Padina gymnospora (RPG), after extracting most of its active components by 70% methanol, was used as an adsorbent material for wastewater treatment. This work also reduces the costs of residue disposal. The adsorption ability of RPG is studied for removing Cd2+ and Cr3+from wastewater. We investigated metal adsorption isotherms and kinetics, the effect of initial metal concentration, contact time, adsorbent dosage, temperature, pH and the RPG reusability on metal ions removal. The results showed that the removal % generally increases with decreasing concentration of metal ions. RPG has higher metal removal percentages reaching 96.2% and 78.8% for Cd2+ and Cr3+, respectively, with a maxiumum adsorption capacity of 96.46 and 31.52 mg/g for Cd2+and Cr3+,respectively at pH 6.2, 50 mg, 25 °C and initial metal concentration of 100 mg/L. The metal ions removal % increased by increasing the dosage of adsorbent and it decreased after a certain limit. The metal removal % slightly changes with increasing temperature for Cd2+ and decreased at high-temperature for Cr3+. The adsorption increased with increasing pH value from 3 to 5, and decreases at pH value of 6.2 then it increased again at pH 8. The removal % and adsorption capacity at pH 8 reaches 99.58%, 99.65%, 99.85 mg/g and 39.86 mg/g for Cd2+ and Cr3+, respectively. The results also showed that RPG can be reused several times for metal ions removal. In addition, Tempkin isotherms and pseudo-second-order kinetic fit the adsorption of Cd2+ and Cr3+ well.

Chemical profile and antioxidant activities of 26 selected species of seaweeds from Kuwait coast

The Kuwait coast is unique with high water temperature (36 °C), salinity (34–45 ppt), and UV index (8–9). Although 113 species of seaweeds are reported from this coast, not much work has been done to explore the bioactive compounds present in these seaweeds and their antioxidant potential. In the present study, water, 50% ethanol, and absolute ethanolic extracts of 26 species of seaweeds collected from the Kuwait coast of Arabian Gulf were screened for phytochemicals, phenolics, and antioxidant activities. Significant variations were observed in phytochemicals, phenolic composition, and antioxidant activities of extracts from various seaweeds. The phenolic content, antiradical power, and reducing power were higher for ethanolic extracts, whereas water extracts showed high iron chelating activity. Canistrocarpus cervicornis and almost all the Sargassum species studied showed better antiradical power and reducing power, while Padina gymnospora and Polysiphonia platycarpa showed the highest iron chelating activity of > 95%. Phytochemical screening of the extracts shows the presence of alkaloids, steroids, terpenoids, and cardiac glycosides. The seaweeds from this geographical location contain more flavonoids than phlorotannins in the temperate counterparts. Interestingly, almost all seaweeds studied contained hydroquinone, a known skin whitening agent. Thus, the seaweeds from this region could be potentially rich sources of antioxidants for food and pharma.

SCREENING OF PHYTOCHEMICAL, ANTIOXIDANT ACTIVITY AND ANTI-BACTERIAL ACTIVITY OF MARINE SEAWEEDS

Objective: Phytochemical is naturally present in the seaweeds which biologically play a significant role. The intention of this study was designed to screen the phytochemical constituents and antimicrobial potential of selected seaweed collected from Rameshwaram and Tuticorin Southern coast of India.Methods: The present study investigated the presence of phytochemical constituents and also total phenol, total carbohydrate and total protein quantity of the brown seaweed. Dictyopteris delicatula, Padina gymnospora, Acanthophora spicifera, Portieria hornemannii and Ulva faciata were extracted with solvents having different polarities like methanol, ethanol, chloroform and water and screened for the phytochemical constituents, total phenol, total carbohydrate, total protein and DPPH with standard procedure. The antibacterial activities of the seaweeds were examined by agar well diffusion method.Results: Among the five seaweeds, U. faciata showed the maximum number of active constituents in the methanol extract likewise P. gymnospora was found to have a number of diligent compounds in ethanol extract. A. spicifera showed minimum compounds in ethanol as well as chloroform extract. Moreover A. spicifera, P. hornemannii have shown the superior quantity of protein and carbohydrate when compared to other species. The scavenging activity of methanol extracts at 5 mg/ml concentration P. hornemannii shows 18.2% and A. spicifera possess 17.1%. In the antibacterial activity, methanol extracts of all the seaweed showed a potential inhibitory activity against B. cereus and P. aeruginosa compared to other pathogens.Conclusion: The crude extract of seaweed manifest preferable antimicrobial and antioxidant activities, hence in the future, it would be good if it is further taken for treatment of human diseases or as new antimicrobial agents to replace synthetic antimicrobial agents.

Synthesis of bio-surfactant based Ag/ZnO nanoparticles for better thermal, photocatalytic and antibacterial activity

Abstract In recent years, synthesis of nanoparticles using natural materials is the essential constituent in the medicinal and clinical laboratory due to inexpensive, recyclable and without use of toxic chemicals. In this present work, SW-Ag/ZnO nanoparticles were synthesized by simple in situ chemical precipitation approach. Padina gymnospora was taken as a bio-surfactant material for preparing Ag nanoparticles and these are further intercalated with ZnO particles. The synthesized nanoparticles were charecterized and confirmed by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, UV–Visible Diffuse reflectance spectroscopy, High resolution scanning electron microscopy and Transmission electron microscopy techniques. The SW-Ag/ZnO was appeared in large clusters with different shaped particles, the size of them was obtained in 14–40 nm. Seaweed capped Ag/ZnO particles showed the greater UV protection values achieved the 45.2% than RSW and SW-Ag. Thermal degradation characteristics of SW-Ag/ZnO have greater thermal stability than RSW and SW-Ag nanoparticles. Moreover, the photocatalytic degradation performances of nanoparticles were tested under the sunlight irradiation using phenol pollutants. Their photocatalytic degradation reaction was well fitted with the first order reaction kinetics. In addition, the antimicrobial activity of nanoparticles was also tested against (Gram (+ve) and Gram (-ve) microbial pathogens and it could be exhibited the higher bacterial inhibition activity obtained for SW-Ag/ZnO than that of RSW and SW-Ag nanoparticles.

Attenuation of oxidative stress induced mitochondrial dysfunction and cytotoxicity in fibroblast cells by sulfated polysaccharide from Padina gymnospora

In this present study, isolation, characterization and protective effect of sulfated polysaccharide (SP) isolated from the brown algae Padina gymnospora was investigated. SP was isolated and characterized through FT-IR, 1H NMR, TGA, GC–MS and CHN analysis. The molecular weight of SP was found to be 16 kDa. The isolated SP contains 29.4 ± 0.35% of sulfate, 27 ± 0.11% of fucose, 0.05 ± 0.12% of protein, respectively. Furthermore, SP exhibits its excellent radical scavenging effects were evaluated by DPPH, ABTS radical scavenging and reducing power assays. Moreover, pretreatment with SP significantly mitigates H2O2 induced cytotoxicity in L-929 cells in a dose dependent manner. Furthermore, SP pretreatment ameliorates oxidative stress induced apoptosis and DNA damage, alleviates the generation of intracellular reactive oxygen species (ROS) and restores mitochondrial membrane potential (MMP) in L-929 cells through its antioxidant potential. Together, these results suggest that SP can be exploited as a natural antioxidant in the food and pharmaceutical industries.

Evaluation of UPF and antibacterial activity of cotton fabric coated with colloidal seaweed extract functionalized silver nanoparticles

In the present study, green synthesis of silver nanoparticles (AgNPs) functionalized with seaweed (Padina gymnospora) extract was investigated. Thus synthesized AgNPs were coated on cotton fabric by pad try-cure method using citric acid as a cross linking agent. The chemical linkage of colloidal AgNPs onto the cellulosic structure are characterized and confirmed by FTIR, SEM, EDX and AFM analysis. The optical, crystalline and morphological features of the functionalized AgNPs were confirmed by UV–Visible, X-ray diffraction and TEM analysis. The size of the functionalized AgNPs was found to be 2–20 nm, there by rendering the small spherical shaped particles are suitable for the biomedical applications. The surface roughness (Ra) of the sample was found to be 70 μm. AgNPs coated fabric getting greater UPF (UV Protection Factor) values than they compared to seaweed extracts coated and uncoated cotton fabric. The antibacterial activity of AgNPs coated fabric was investigated, getting greater inhibition effect against S. aureus (Gram positive) and E. coli (Gram negative) microbial strains. Durability of the AgNPs coating was also tested after 10 repeated washings. Then after the 10 repeated washings of AgNPs coated fabric provided the better retainable UV protection efficiency and microbial inhibitory activity results obtained as for the before washings with slight changes.

Enhanced photocatalytic activity of Ag-ZnO nanoparticles synthesized by using Padina gymnospora seaweed extract

In this present study, reported the Padina gymnospora seaweed extract mediated synthesis of Ag-ZnO nanoparticles by the chemical co-precipitation method. Thus synthesized SW/Ag-ZnO nanoparticles were characterized by FTIR, UV–Visible, HR-SEM and TEM analysis. The strong chemical bonding interactions of Zn2+ and Ag+ ions on the seaweed biomolecules were confirmed by FTIR and UV–Visible spectroscopy. The spherical and grain shaped morphology of Ag, ZnO particles intercalated on the seaweed polymer component was verified by HR-SEM and TEM analysis and their average size of the particles was obtained in 20–40 nm range. In addition, the surface area and pore volume distribution of SW/Ag-ZnO (55.14 m2 g−1 and 0.1830 cm3/g) was found to be higher than SW-ZnO nanoparticles. Photodegradation and decolorization performances of the catalyst nanoparticles were tested by cationic (Methylene Blue) and anionic (Reactive Blue 198) dyes under the direct sunlight irradiations. The photocatalytic degradation activity of SW/Ag-ZnO nanoparticles were fitted to the first order reaction kinetics, the rate constant values of 0.026 and 0.024 min−1 obtained for the MB and RB198 dyes and the removal of 85 and 95% degradation was achieved within the irradiation period of 30 min exposure than the other nanoparticles. The mineralization of MB and RB198 dyes were confirmed by Chemical oxygen demand (COD) measurements.

Effect of antioxidant compounds from seaweeds on storage stability of C20-22 polyunsaturated fatty acid concentrate prepared from dogfish liver oil

Ethyl acetate extracts of seaweeds were chromatographically fractionated to yield 14-methyl pentyl tetrahydro-8-hydroxy-10-methylnaphthalene–8-carboxylate (1) and tetrahydro-4-isopropyl-9-(9, 14-dimethyldec-9-enyl)-pyran-1-one (2) from Sargassum ilicifolium, whereas Padina gymnospora afforded dihydro-2-(10-(hydroxymethyl)-7,15-dimethyl-9-oxoundec-11-enyl)-2-methyl-2H-pyran-1(4H)-one (3) and 1-(decahydro-1-hydroxy-7-methyl-8-vinylnaphthalen-2-yl)ethanone (4) as major constituents. Compound 1 displayed significantly higher antioxidant activity (IC50 < 1 mg/mL, p < 0.05) comparable to other analogues (IC50 > 1 mg/mL). The C20-22 polyunsaturated fatty acid (C20-22 PUFA) concentrate (CFA) prepared from the deep-sea dogfish liver oil was added with the studied compounds and physiochemical properties and fatty acid composition during an accelerated storage were evaluated. No significant reduction in C20-22 PUFAs (∼6%) in the CFA treated with 1 as compared to that with the control (∼35%) was recorded. A greater induction time was observed for the CFA supplemented with 1 (6.8 h) than other compounds (≤6 h) and control (∼1.6 h), maintaining the oxidation indices of the CFA within desirable limits.

Bibliographical Checklist of marine and estuarine phytobenthos of Ilha Grande, Ilha Grande state park, Angra dos Reis, Rio de Janeiro, Brazil

This paper is a taxonomically updated floristic inventory and a bibliographical summary of the marine and estuarine benthic flora located in the buffer zone of Ilha Grande State Park, Angra dos Reis, Rio de Janeiro, Brazil (coordinates: latitude 22° 50’S between 23° 20’S and longitude 44° 00’W between 44° 45’W). A total of 26 papers were found dating from 1928 to 2016. The surveys at Ilha Grande can be divided into three periods: a) taxonomical studies at specific points, b) taxonomic in­ventories in certain areas, c) ecological surveys located in the north/northwest region of the island. A total of 256 phytobenthic taxa were recorded for Ilha Grande, which makes it the richest insular marine benthic flora published on the Brazilian coast. The richest taxonomic division was the Rhodophyta with 156 taxa, followed by the Chlorophyta division with 51 taxa and the Ochrophyta division with 49 taxa. The predominant orders were: red algae: a) Ceramiales (49%); b) brown algae: Ectocarpales (29%); c) green algae: Cladophorales (45%). The most frequent taxa were: green algae: Ulva flexuosa Wulfen subsp. flexuous and Ulva fasciata Delile (40% each); b) brown algae: Padina gymnospora (Kutzing) Sonder (47%), c) red algae: Gelidium sp. [= G. pusillum (Stackh.) Le Jol. var. pusillum (53%)].

Cell wall physicochemical properties determine the thallus biomineralization pattern of Padina gymnospora (Phaeophyceae).

Approximately half of the Padina (Dictyotales, Phaeophyceae) species mineralize aragonite needles over the adaxial thallus surface, where mineral bands are interspersed with nonmineralized regions along the thallus from the apical to basal end. However, this calcification pattern and the related algal properties are not well understood. Therefore, this work was performed to elucidate a potential role of cell walls in the inhibition/induction of mineralization in the brown alga Padina gymnospora. In a comparison of specific thallus regions, differences were identified in the cellulose distribution, microfibrils arrangement and thickness, distribution and abundance of phenolic substances, and physical differences among the surfaces of the thallus (deformation, adhesion, topography, and nano-rugosity). In vitro mineralization assays indicated that phenolic substances are strong modulators of calcium carbonate crystals growth. In addition, de novo mineralization assays over cell wall surfaces that were used as templates, even without cellular activity, indicated that the cell wall remains a key factor in the induction/inhibition of mineralization. Overall, the current findings indicate a strong correlation between the physico-chemical and structural properties of the cell wall and the alternation pattern of the mineralization bands over the thallus of P.gymnospora.

Production and Biotechnological Application of Extracellular Alkalophilic Lipase from Marine Macroalga-Associated Shewanella algae to Produce Enriched C20-22 n-3 Polyunsaturated Fatty Acid Concentrate.

An extracellular alkalophiliclipase was partially purified from heterotrophic Shewanella algae (KX 272637) associated with marine macroalgae Padina gymnospora. The enzyme possessed a molecular mass of 20kD, and was purified 60-fold with a specific activity of 36.33U/mg. The enzyme exhibited Vmax and Km of 1000mM/mg/min and 157mM, respectively, with an optimum activity at 55°C and pH10.0. The catalytic activity of the enzyme was improved by Ca2+ and Mg2+ ions, and the enzyme showed a good tolerance towards organic solvents, such as methanol, isopropanol, and ethanol. The purified lipase hydrolyzed the refined liver oil fromleafscale gulper shark Centrophorus squamosus, yielding a total C20-22 n-3 PUFA concentration of 34.99% with EPA+DHA accounting the major share (34% TFA), after 3h of hydrolysis. This study recognized the industrial applicability of the thermostable and alkalophilic lipase from marine macroalga-associated bacterium Shewanella algae to produce enriched C20-22 n-3 polyunsaturated fatty acid concentrate.

Previously Undescribed Antibacterial Polyketides from Heterotrophic Bacillus amyloliquefaciens Associated with Seaweed Padina gymnospora.

A heterotrophic marine bacterium Bacillus amyloliquefaciens isolated from seaweed Padina gymnospora exhibited broad spectra of antibacterial activities against pathogenic bacteria Aeromonas hydrophila, Vibrio harveyi, Vibrio vulnificus, and Vibrio parahaemolyticus. The seaweed-associated B. amyloliquefaciens was recognized to possess functional type I polyketide synthase-1 (pks-1) gene, and was used to isolate four homologous compounds with polyketide frameworks. The compounds were characterized as 11-(15-butyl-13-ethyl-tetrahydro-12-oxo-2H-pyran-13-yl) propyl-2-methylbenzoate (1), 9-(tetrahydro-12-isopropyl-11-oxofuran-10-yl)-ethyl-4-ethoxy-2-hydroxybenzoate (2), 12-(aminomethyl)-11-hydroxyhexanyl-10-phenylpropanoate (3), and 7-(14-hydroxypropan-13-yl)-8-isobutyl-7,8-dihydrobenzo[c]oxepin-1(3H)-one (4) by comprehensive nuclear magnetic resonance and mass spectroscopic experiments. The compounds 1-4 displayed significant antibacterial activities against clinically important pathogens V. parahaemolyticus and V. vulnificus (inhibitory zone diameter of ≥15mm, 100mcg on disk). The electronic and hydrophobic parameters appeared to hold a conspicuous part in directing the antibacterial properties of the compounds. This study revealed seaweed-associated B. amyloliquefaciens as potential source of antimicrobial polyketides for pharmaceutical applications.

The importance of shore height and host identity for amphipod assemblages

ABSTRACTThe spatial distribution of organisms associated with marine intertidal macroalgae may be a direct result of their tolerance to air exposure or an indirect consequence of the distribution of their host. We compared amphipod assemblages from five intertidal macroalgae to investigate their relationship with algal identity. To test the effect of height regardless of algal characteristics, we transplanted coralline algal turfs to three different levels within the intertidal zone and compared amphipod assemblages after 1 and 14 days. Interstitial volume was positively correlated to the abundance of amphipods, suggesting that this attribute may correspond better to the potential space for their occupation when compared to algal biomass, thallus volume or the ratio between thallus and interstitial volume. Algal level determined the structure of the amphipod assemblages. Upper-level (Acanthophora spicifera and Caulerpa racemosa) and intermediate-level (coralline) algae host similar amphipod assemblages dominated by Apohyale media, but different from lower-level algae (Padina gymnospora and Sargassum cymosum), which were dominated by Hyale niger. Ten of the 15 amphipod species reported from natural communities were found in the transplanted plots. Distinct pools of amphipod species colonized coralline transplants at upper and lower levels after 1 day. However, regardless of the position on the shore, transplanted coralline turfs supported similar assemblages after 14 days, indicating that algal identity is also important for species assemblages. Our results suggest that both height on the shore and host identity combine to determine the vertical structure of amphipod assemblages in the rocky intertidal.