Showing papers on "Turbinaria ornata published in 2021"

Landscape-scale patterns of nutrient enrichment in a coral reef ecosystem: implications for coral to algae phase shifts.

Abstract: Nutrient pollution is altering coastal ecosystems worldwide. On coral reefs, excess nutrients can favor the production of algae at the expense of reef-building corals, yet the role of nutrients in driving community changes such as shifts from coral to macroalgae is not well understood. Here we investigate the potential role of anthropogenic nutrient loading in driving recent coral-to-macroalgae phase shifts on reefs in the lagoons surrounding the Pacific island of Moorea, French Polynesia. We use nitrogen (N) tissue content and stable isotopes (δ15 N) in an abundant macroalga (Turbinaria ornata) together with empirical models of nutrient discharge to describe spatial and temporal patterns of nutrient enrichment in the lagoons. We then employ time series data to test whether recent increases in macroalgae are associated with nutrients. Our results revealed that patterns of N enrichment were linked to several factors, including rainfall, wave-driven circulation, and distance from anthropogenic nutrient sources, especially human sewage. Reefs near large watersheds, where inputs of N from sewage and agriculture are high, have been consistently enriched in N for at least the last decade. In many of these areas, corals have decreased and macroalgae have increased, while reefs with lower levels of N input have maintained high cover of coral and low cover of macroalgae. Importantly, these patchy phase shifts to macroalgae have occurred despite substantial island-wide increases in the density and biomass of herbivorous fishes over the time period. Together, these results indicate that nutrient loading may be an important driver of coral-to-macroalgae phase shifts in the lagoons of Moorea even though the reefs harbor an abundant and diverse herbivore assemblage. These results emphasize the important role that bottom-up factors can play in driving coral-to-macroalgae phase shifts and underscore the critical importance of watershed management for reducing inputs of nutrients and other land-based pollutants to coral reef ecosystems.

Comparative assessment of different biofertilizers in maize (Zea mays L.) cultivation

Abstract: Agriculture depends on different fertilizers ranging from living organism to wide range of synthetic chemicals. Due to the elevated toxic effects of chemical fertilizer, there is an urgent need for organic farming and cultivation. The current study aimed to use bacteria (Rhizobium, Azotobacter and Azospirillum), fungi (Trichoderma) and marine macroalgae (Turbinaria ornata) as efficient biofertilizers for maize cultivation and further to compare their effects under various conditions. Soil and irrigating water were evaluated for the physical, chemical and biological parameters prior to the experiments. Bacteria, fungi and macroalgae were used in four different concentrations (25%, 50%, 75% and 100%) by using two different treatment methods (soil drench, seed coat). Seeds were soughed, watered and it was followed to monitor the growth and yield. Soil texture exhibits silt clay loam with percolation rate (3.11 min), water holding capacity (19%), capillary action (3.05 min), macronutrient (nitrogen 101 ppm, phosphorous 6 ppm and potassium 410 ppm) and micronutrient (zinc 0.9 ppm, iron 5.2 ppm, copper 1.0 ppm, manganese 2.1 ppm) and was present in the soil. Irrigating water contains sodium 7.9 mEq/l, potassium 4 mEq/l, calcium 0.4 mEq/l, magnesium 1.7 mEq/l, chlorine 0.405 mEq/l, sulphate 3.3 mEq/l and bicarbonate 0.7 mEq/l. Escherichia coli, Clostridium sp., Proteus sp., Bacillus sp., Corynebacterium sp. and Erwiana sp. were isolated from untreated soil sample. At both early stage and flowering stage, the chlorophyll content was high in Turbinaria ornata, whereas Rhizobium elicits very low content among the subjected groups. Soil enzyme dehydrogenase (0.95 μU/g), phosphatase (47.5 μU/g) and protease (14.3 μU/g) increased in the Turbinaria ornata treatment. Soil was enriched with Rhizobium, Azotobacter, Azospirillum, Trichoderma and Actinomycete during flowering stage. Maximum plant height (137.8 cm) was observed in T. ornata seed coat method as compared to other groups. Trichoderma treated obtained minimum in plant height. Root length and number of leaves were increased in macroalgae treatment than the other treatment. The weight of one maize seed was found to be maximum (147.8 g) in soil drench 100% treated. In case of yield, Turbinaria ornata–treated maize flour contains protein 14.47 mg/100 g, carbohydrate 81.03 mg/100 g, lipids 4.8 mg/100 g, total fiber 8 mg/100 g and total sugar 0.79 mg/100 g with macro- and micronutrients. Turbinaria ornata treatment shows better growth and yield in maize cultivation than other treatments.

A systematic analysis of hexavalent chromium adsorption and elimination from aqueous environment using brown marine algae (Turbinaria ornata)

Abstract: In this study, chromium (VI) adsorption was explored using Turbinaria ornata as sorbent and the effects of parameters like temperature, sorbent size, contact time, sorbent dose, and agitation speed were improved using the response surface method. The optimal condition for maximum adsorption of Cr (VI) was found as solution temperature (33.6 °C), sorbent size (0.786 mm), contact time (215 min), agitation speed (117 rpm), and adsorbent dose (2.7 g/l). The maximum removal percentage was found to be 95.25%. The investigational data was also studied using various adsorption models. From the Langmuir model, it was observed that a maximum Cr (VI) uptake of 44.95 mg/g was achieved. Thermodynamic constraints such as ΔG°, ΔH°, and ΔS° have been assessed and it has been originating that the sorption procedure was impulsive and heat releasing in nature. A high R2 value, low root mean square error (RMSE), and mean absolute percentage error (MAPE) suggest that the Cr (VI) adsorption follows the pseudo-first-order model. The characterization of absorbent was studied by FTIR and SEM. The FTIR exposed the connection of some functional groups such as carboxylic acid, hydroxyl, and amino in the adsorption of Cr ions. From all of our data, we conclude that the Turbinaria ornata explored in this work displayed good potential for chromium elimination from synthetic solutions.

Influence of commercial farming of Kappaphycus alvarezii (Rhodophyta) on native seaweeds of Gulf of Mannar, India: Evidence for policy and management recommendation

Abstract: Seemingly unabated global demands for raw materials of red seaweeds for k-carrageenan have expanded commercial cultivation of Kappaphycus alvarezii in the extended areas of the tropics. However, this has also increased speculations of negative environmental effects of K. alvarezii cultivation on the native marine biota. In the present investigation the native seaweed diversity was studied from 2018–2019 in four months interval within the intertidal regions of 19 islands of the Gulf of Mannar. Data gathered were divided in to two categories, i.e. islands near to cultivation sites (2–8 km away) and far from cultivation sites (30–70 km away) revealed occurrence of 113 and 122 seaweed species respectively. Significance differences were observed only in percentage cover (F = 6.505; p = 0.013) and species richness (F = 10.312; p = 0.002) in between the two group of islands. Simpson diversity and Shannon Weaver indices were in the range of 0.870—0.884 and 2.554—2.707 respectively and no significant differences recorded between the two group of islands (p > 0.05). A Bray–Curtis Similarity index (95%) indicated a homogenous distribution of seaweed diversity. Dictyota dichotoma, Halimeda gracilis, Padina pavonica, Sargassum polycystum and Turbinaria ornata were the most common species in both groups of islands. The present study confirmed that commercial farming of K. alvarezii did not affect the native seaweeds diversity in the islands of the Gulf of Mannar.

Turbinafuranone A–C, new 2-furanone analogues from marine macroalga Turbinaria ornata as prospective anti-hyperglycemic agents attenuate tyrosine phosphatase-1B

Abstract: Chemical investigation of Phaeophytan marine macroalga Turbinaria ornata (family Sargassaceae) resulted in the characterization of three 2-furanone analogues, which were characterized as 6, 7-dihydroxy-8-methyl-3-(5′-methyloct-4′-en-1′-yl)-hexahydrocyclooct-1-en-[1, 2-c]furan-11-one (turbinafuranone A), 4-hydroxy-3-isopropyl-7, 8-dimethyl-6-(pentan-2′-acetate)-hexahydrocycloocta-1-en-[1, 2-c]furan-11-one (turbinafuranone B), and 6-acetoxy-8-ethyl-5-methoxy-3-(2′-methylhex-4′-en-1′-yl)-pentahydrocycloocta-1, 7-dien-[1, 2-c]furan-11-one (turbinafuranone C). Inhibitory property of turbinafuranone B against tyrosine phosphatase-1B was significantly greater (IC50 2.42 mM) than standard agent sodium metavanadate (IC50 2.52 mM). Greater electronic properties along with molecular docking experiments corroborated the attenuation property of turbinafuranone B against protein tyrosine phosphatase-1B, by exhibiting minimum binding energy of −11.80 kcal/mol compared to other studied analogues. The results demonstrated that the undescribed turbinafuranone B might be used as prospective natural anti-hyperglycemic lead to alleviate the likelihood of higher postprandial blood glucose levels.

Assessment of Antioxidant Capacity and Phytochemical Composition of Brown and Red Seaweeds Sampled off Red Sea Coast

Abstract: Seaweeds are becoming a viable source of biologically active composites with a hopeful application as nutraceuticals, functional food components, and medicinal agents. In the present study, the antioxidant capacity and biochemical compositions of four seaweeds; Polycladia indica and Turbinaria ornata (Phaeophyceae) and Laurencia obtusa and Sarconema scinaioides (Rhodophyceae), were estimated. The results indicated that T. ornata showed the maximum value of total phenolic compound (TPC), flavonoid content, β-carotene, carbohydrate and has maximum percentage of DPPH radical scavenging capacity, total antioxidant capacity (TAC), and total reducing capacity (TRC) (72.48%, 15.02%, and 53.24% inhibition, respectively), while the highest contents of ascorbic acid, lipid, calcium, and zinc were observed in L. obtusa. P. indica showed the highest protein contents, dietary fibers, sodium, potassium, magnesium, and total amino acids. Glutamic, aspartic, proline, and methionine were the most frequent amino acids in the four selected seaweeds. Brown seaweeds (T. ornata and P. indica) attained the highest percent of the total polyunsaturated (ω6 and ω3) essential fatty acids. The biochemical content of these seaweed species, as well as their antioxidant properties, make them interesting candidates for nutritional, pharmacological, and therapeutic applications.

Macroalgal release of dissolved organic carbon in coral reef and its interaction with the bacteria associated with the coral Porites lutea

Abstract: Macroalgae supersede corals in the reefs worldwide, converting the coral-dominant systems into algal-dominant ones. Dissolved organic carbon (DOC) released by macroalgae play a prominent role in degrading the coral reefs by stimulating the bacterial growth and metabolism. However, the long-term remineralization of macroalgal DOC and their contribution to the carbon pool are least studied. In this study, we quantified the DOC released by five species of macroalgae that affected live corals through their physical contact and their subsequent remineralization for 100 days by coral mucus bacteria. Also, we analyzed the changes in bacterial community structure after 30 days of exposure to the macroalgal DOC. All the macroalgae released a significant amount of DOC ranging from 2.2 ± 0.17 to 8.1 ± 0.36 μmol C g-1 h-1 (mean ± SD). After 100 days, between 9.2 and 30.9% of the macroalgal DOC remained recalcitrant to bacterial remineralization. There was no apparent change in the dominant bacterial groups exposed to the DOC released by the green macroalgae Caulerpa racemosa and Halimeda sp. In comparison, the Proteobacteria group decreased with a prominent increase in the Firmicutes, Planctomycetes, and Bacteroidetes group in the samples exposed to DOC released by the brown macroalgae Turbinaria ornata, Sargassum tenerrimum, and Padina gymnospora. These inclusive data suggest that the DOC released by different species of macroalgae differed on their lability to microbial mineralization and highlight the comparable patterns in microbial responses to macroalgal exudates across different species.

Antithrombotic, Antihemolytic Activities and Protein ConjugationProperties of Silver Nanoparticles Synthesized from Turbinaria ornata

Abstract: Green synthesis of silver nanoparticles synthesized from Turbinaria ornata weed extract was carried out. Because these seaweeds are largely unexplored and contain botanical molecules that promote bimolecular reduction. In this study, silver nanoparticles (AgNPs) cause a rise in the accumulation of clotting factors, platelets and procoagulant activity, both of which lead to thrombotic and hemolytic diseases. The silver nanoparticles were initially characterized using spectroscopic analysis to validate the biomolecules of Turbinaria ornata involved in nanoparticle reduction. A detailed study on the effectiveness of silver nanoparticles on antithrombolytic activity in adult blood samples confirms the interaction of nanoparticles with platelets and blood vessels, which is significant in the production of thrombosis and cardiovascular diseases. The antihemolytic activity was tested to assess the percentage of blood clot lysis in order to confirm the ability to scavenge hydrogen peroxide in a concentration dependent manner. The protein conjugation and binding activities of major, secondary, and tertiary structures were also investigated in silico. Thus, Turbinaria ornata seaweeds with reduced silver nanoparticles demonstrated increased antithrombotic and antihemolytic activities, suggested that they could be used as novel therapeutics for cardiovascular diseases.

Phytochemical Analysis, In Vitro Antioxidant, and Wound Healing Activities of Turbinaria ornata (Turner) J. Agardh from Gulf of Mannar, India.

Abstract: Turbinaria ornata (Turner) J., tropical brown algae, was found in the South Pacific and Indian Ocean ecosystems. In accordance with recent studies, Turbinaria ornata J. has potent anti-inflammatory effects. Therefore, this study is aimed to explore the biological activities of ethanolic extract of T. ornata J. by analyzing the presence of phytochemical components, antioxidant property, antimicrobial activity, and the wound healing activity. From the results, phytochemical analysis of ethanolic extract of T. ornata J. showed the presence of alkaloids, saponins, oils, total phenolic, and total flavonoid content which were estimated to be 0.683±0.001 Abs and 0.433±0.001 Abs, respectively. Antioxidant activity of the ethanolic extract of T. ornata J. extract showed remarkable DPPH radical scavenging activity of about 58.8% at 200μg/mL and total antioxidant activity of 0.257 Abs at 100μg/mL concentration, as compared to that of their respective controls. The ethanolic extract of T. ornata J. exhibited the maximum zone of inhibition against the clinical pathogens like Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Candida albicans, and Methicillin-resistant Staphylococcus aureus with their potent antimicrobial activity. Wound healing effects of the ethanolic extract of T. ornata J were analyzed by using zebrafish model. The results showed the rapid and significant regeneration of the wounded caudal fin on day 14. Therefore, the preliminary results of this study strongly support that the ethanolic extract of T. ornata J. may be effective in wound healing and regeneration of the wounded tissues.

Nematicidal Properties of Methanolic Extracts of Two Marine Algae against Tomato Root-Knot Nematode, Meloidogyne incognita

Abstract: Red algae Phacelocarpus tristichus J. Agardh and brown algae, Turbinaria ornata J. Agardh at three concentrations (0.5, 1.0, and 2.0%) were evaluated for the management the infection of Meloidogyne incognita for tomato plants in controled conditions.The methanolic extracts of the two species improved growth parameters of the infected and uninfected plants. Both P. tristichus and T. ornata methanolic extracts pronounced nematicidal activities against M. incognita infecting tomato. Accordinglly, P. tristichus (2.0%) shows significant suppression for root galling, the number of developmental stages, females, egg masses, eggs/ egg mass and total nematode population. However, T. ornata at different concentrations surpassed P. tristichus and significantly induced chemical constitutions in terms of NPK, crude proteins and carbohydrates in dried leaves of infected tomato with M. incognita. It could be concluded that, P. tristichus and T. ornata were recommended as biofertilizers and a promising tool in the integrated management of M. incognita infecting tomato.

Subtidal macrophyte diversity and potentials in Nha Trang Bay - baseline data for monitoring a rising natural resource

Abstract: Tropical coastal ecosystems provide a unique complex marine habitat with a high diversity of algal species, Viet Nam being a particular hotspot. These algae may host a variety of potential unknown or underestimated bioactive algal compounds. In parallel the worldwide rising interest in macroalgae-based products leads to increasing activities in seaweed natural harvest and mariculture within coastal waters. With this growing interest, the present work provides baseline data for a systematic and science-based macroalgal monitoring program in Nha Trang Bay, Viet Nam, to keep track of potentially interesting taxa and to identify driving environmental factors which may also naturally influence biodiversity and species abundance. The present study investigated macrophyte diversity and abundance by combining a qualitative and quantitative macroalgal survey approach with environmental sampling (e.g. physicochemical properties of water column, underwater light regime, and sediment characteristics). Surveys were performed in the dry season (May/June) 2019 in different water depths (3, 6 and 10 m) at seven sites within Nha Trang Bay. The study revealed a coastal patchwork of diverse habitats inhabited by complex macrophyte communities, including estuarine dense Sargassum forests and Turbinaria meadows, sheltered sandy seagrass (Halodule spp.) beds with upcoming Lyngbya blooms, low diverse Padina deserts and highly turbid aquaculture (lobster and fish farms) impacted sites with surprisingly high macroalgal diversity. During our study a total of 86 macrophyte species were encountered in the subtidal (>1 m water depth), whereas only 6 species (Padina australis, Sargassum mcclurei, Turbinaria ornata, Halimeda discoidea, Amphiroa fragilissima, Tricleocarpa cylindrical) were frequently found at every survey site. The observed high patchiness and presence of economically important (e.g. Sargassum spp., Gracilaria spp., Caulerpa spp., Gelidiella acerosa, Acanthophora spicifera) and potentially economically interesting (e.g. Padina australis, Turbinaria ornata, Stypopodium zonale, Chondria armata) taxa during the survey underlines the high potential of the present macrophytic bio-resource, which apparently is strongly structured and will be altered by the changing heterogenic environment.