Turbinaria Ornata Research Articles

Free and bound phenolic profiles and antioxidant ability of eleven marine macroalgae from the South China Sea.

Marine macroalgae are of broad interest because of their abundant bioactive phenolic compounds. However, only a few previous studies have focused on bound phenolic compounds. In this study, there were significant differences in total phenolic content, total phlorotannin content, total flavonoid content, and antioxidant ability in free and bound forms, as well as in their bound-to-free ratios, among 11 marine macroalgal species from the South China Sea. Padina gymnospora had the highest total phenolic content of free fractions, and total phlorotannin content, total flavonoid content, and antioxidant activity of free fractions. Sargassum thunbergii had the highest total phlorotannin content of bound fractions, whereas Sargassum oligocystum had the highest total flavonoid content and total phenolic content of bound fractions. Moreover, 15 phenolic acids, 35 flavonoids, 2 stilbenes, 3 bromophenols, and 3 phlorotannins were characterized and quantified using ultra-high-performance liquid chromatography with Xevo triple quadrupole mass spectrometry, and 42 phenolic compounds were reported in the bound fractions of seaweeds for the first time. Among the species, the number and amount of free and bound phenolic compounds varied greatly and the main components were different. Padina gymnospora had the largest total phenolic number, while Turbinaria ornata showed the highest total phenolic amount. Coutaric acid and diosmetin were dominant in Sargassum polycystum, and hinokiflavone was dominant in Caulerpa lentillifera, and cyanidin was dominant in the other seaweeds. Hierarchical cluster analysis was used to divide the seaweed species into seven groups. This study revealed that Padina gymnospora, Sargassum thunbergii, Turbinaria ornata, and Sargassum oligocystum are promising functional food resources.

Assessment of the conceivable inhibitory activity of pathogenic microorganisms extracted from seaweed using phytochemicals, antioxidants, and in-silico molecular dynamic simulation

Turbinaria ornata, Polycladia myrica, and Padina pavonica is a perennial Mediterranean-native seaweed that is commonly used for mass display. The principal aims of this reconnaissance were the isolation of various compounds from methanolic seaweeds extraction and screening the potential effect as antibacterial, and antioxidant. The micro-dilution method was used to measure antibacterial activity. Gas chromatography-mass spectrophotometry (GC. Mass) abused to analyze the chemical components of the methanolic seaweed extract. The existence of 19 secondary metabolites was discovered using GC–MS analysis: 8 different compounds for each seaweed's species. Among these bioactive compounds, 4 compounds from P. pavonica extract showed the binding affinity and ability to react with Beta-ketoacyl synthase (PDB ID 1EK4) of Escherichia coli. The phytocompounds' drug-like and poisonous characteristics were predicted. Auto Dock was used to examine the ligand receptor complexes' binding strength. T. ornate and P. pavonica had the highest activity against K. pneumonia, with 22.50 mm (0.78 µg/ml) and 22.23 mm (5.10 µg/ml) obtained, respectively. In a concentration-dependent manner, the extract components demonstrated substantial antioxidant activity. P. pavonica had the highest scavenging activity (78.00%, IC50 = 6.35 µg/ml), while ascorbic acid had a 96.45% scavenging impact. Because the chemicals bind to the Lipinski Ro5, they have drug-like characteristics. The compounds had no hepatotoxic effects. P. pavonica extract has the prospect of being used as a source of medicinal drug-like chemicals. The docking investigation found a strong correlation between the experimental results and the docking results. Finally, brown seaweed extract, particularly P. pavonica extract, demonstrated strong antibacterial, antioxidant, and free radical scavenging properties.

Ameliorative effects of Turbinaria ornata extract on hepatocellular carcinoma induced by diethylnitrosamine in-vivo.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths and the fifth most common cancer worldwide. Brown algae appeared to be a rich source of efficient and safe agents against many life-threatening diseases like cancer. Thus, the scope of this study was to investigate the therapeutic effects of Turbinaria ornata against experimentally induced HCC in a rat model. Accordingly, forty male albino rats were divided into four groups. HCC was induced by intraperitoneal injection with diethylnitrosamine (DENA) followed by carbon tetrachloride (CCL4). After four weeks of DENA + CCL4 injection and two weeks of treatment with Turbinaria ornata, rats were sacrificed to collect hepatic tissue and blood samples for histopathological observations and various biochemical markers such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alpha-fetoprotein (AFP), urea, creatinine, albumin (ALB), and alkaline phosphatase (ALP). Rats that were injected for four weeks with DENA + CCL4 showed a significant increase in AFP levels, transforming growth factor-beta (TGF-β) and tumor necrosis factor-alpha (TNF-α), as well as a high percentage of malignant changes in hepatic tissues. The extension of malignant changes in the rat liver tissues was markedly reduced using Turbinaria ornata, as the treatment displayed liver patterns similar to that of the normal control rats. Furthermore, rats with HCC fed with Turbinaria ornata extract for two weeks showed decreasing levels of TGF-β and TNF-α. These findings demonstrate that Turbinaria ornata supplement can prevent HCC development in hepatic rats; however, the exact mechanism requires further investigation.

Insight application of cytotoxicity assay of Turbinaria Ornata (Brown seaweed) with reference to anticancer properties

Insight application of cytotoxicity assay of Turbinaria Ornata (Brown seaweed) with reference to anticancer properties

Synthesis and characterization of Turbinaria ornata mediated Zn/ZnO green nanoparticles as potential antioxidant and anti-diabetic agent of enhanced activity

Turbinaria ornata marine macro-algae (TUN) have been applied as carriers for the metallic zinc/ZnO blended nanoparticles, which were synthesized by implementing the extracted phytochemicals of the algae. The resulting hybrid bio-composite (Zn@ZnO/TUN) was characterized as a potential product of promising antioxidant and antidiabetic characteristics in synergetic studies. The obtained composite demonstrate t6he existing or complex biological active groups related to zinc (Zn-O stretching and tetrahedral Zn coordination) and organic groups (amino, methyl, carboxylic, alkynes, P=O, C–C–O, C=N, and N–O) corresponding to the extracted phytochemicals of algae (polysaccharides, phospholipids, lipids, fucose, and phosphodiester). The assessment of Zn@ZnO/TUN hybrid as an anti-oxidant agent validated excellent effectiveness towards the commonly examined radicals (DPPH (88.2 ± 1.44%), nitric oxide (92.7 ± 1.71%), ABTS (90.5 ± 1.8%), and O2●− (30.6 ± 1.32%), considering the determined performance for the commercially used standard (ascorbic acid). Regarding the antidiabetic properties, the incorporation of Zn@ZnO/TUN inhibits the function and activities of the key oxidizing enzymes, either the commercial forms (α-amylase (88.7 ± 1.3%), α-glucosidase (98.4 ± 1.3%), and amyloglucosidase (97.3 ± 1.4%) or the crude intestinal active forms (α-amylase (66.2 ± 1.4%) and α-glucosidase (95.1 ± 1.5%). This inhibitory effectiveness of Zn@ZnO/TUN is significantly better than the measured performances using commercialized miglitol drugs and slightly better than acarbose. Considering the expense and adverse effects of conventional medications, the synthesized Zn@ZnO/TUN blend could be evaluated as a marketable antidiabetic and antioxidant medication. The findings also demonstrate the influence of the derived phytochemicals from Turbinaria ornata and the incorporation of its algae residuals as carriers for the metal nanoparticles on the biological function of the composite. The cytotoxicity investigation reflected safety effect of the composite on colorectal fibroblast cells (CCD-18Co) (96.3% cell viability) and inhibition effect on cancerous colorectal cells (HCT-116) (47.3% cell viability).

Application of the Longline Method of Seaweed Turbinaria ornata Cultivation through Spacing Treatment

Application of the Longline Method of Seaweed Turbinaria ornata Cultivation through Spacing Treatment

Nutritional Properties, Antioxidant Activity, and Heavy Metal Accumulation in Selected Marine Macro-Algae Species of Sri Lanka

In recent years, the emergence of drug resistance and sensitivity in leading diseases has heightened global interest in natural nutraceuticals as primary health supplements. However, comprehensive scientific scrutiny is essential before marketing these as supplements. In this study, we assessed the nutritional composition, antioxidant activities, and trace metal accumulation in eleven selected Sri Lankan coastal seaweed species. Gracilaria corticata had the highest (p < 0.05) ash and crude fiber content among the species. Protein content ranged from 4.87% to 23.67% (DW), with Ulva rigida displaying the highest (p < 0.05). Crude fat content ranged from 0.09% to 4.13% (DW), with Cladophora herpestica having the highest (p < 0.05) crude fat content. Sargassam cinereum, Turbinaria ornata and Sargassum crassifolium had the highest (p < 0.05) TPC content (51.32 ± 0.61–28.90 ± 2.68 mg/GAE g) and the highest (p < 0.05) radical scavenging antioxidant activity compared to other seaweeds. The study findings indicate that most of the studied metals in seaweeds exceeded the WHO-recommended levels. Aluminum was the highest (p < 0.05) accumulated metal in seaweeds compared to other metals. Toxic heavy metals, such as arsenic, cadmium and chromium, levels in all of the studied seaweeds surpassed the WHO limits. While seaweeds displayed acceptable nutritional and antioxidant properties, heavy metal presence poses a potential health risk to consumers. Products using seaweeds with accumulated heavy metals may have lower nutritional quality. Thus, this study underscores the need for comprehensive scientific investigation before developing high-quality natural food products or supplements from seaweeds.

Screening of Bioactive Compounds of the Brown Algae Turbinaria ornata (Turner) J. Agardh, 1848 From The Coastal Waters of Aboru Village, Central Maluku Indonesia

One of the most important communities in the seawater ecosystems is the brown algae where Turbinaria ornate is a brown alga species which is rich in nutrients and bioactive compounds. The bioactive components of T. ornata are beneficial for people living along the coast, particularly in Maluku region, an archipelagic region, as well as for the medical and pharmaceutical sectors. The research sample was the brown algae T.ornata obtained from the coastal waters of Aboru Village. Screening of bioactive compounds was carried out qualitatively using different reagents and indicated by the appropriate color change to ensure the presence of bioactive compounds which include phenolics, tannins, flavonoids, saponins, triterpenoids, steroids, alkaloids and anthocyanins. This study's findings demonstrated that while triterpenoids, quinones, and anthocyanins were absent, tannins, saponins, alkaloids, steroids, phenolics, and flavonoids were present in high concentrations. In conclusion, T. ornata includes bioactive compounds like tannins, saponins, alkaloids, steorids, phenolics, and flavonoids, according to this study's findings. Keywords: bioactive compound, brown algae, qualitative screening, Turbinaria ornata

Antibacterial Ability of Seaweed Endophytic Bacteria (Turbinaria ornata, Sargassum crassifolium, and Sargassum polycystum) Against Skin Disease Agents

Bioactive substances that can prevent the growth of pathogenic germs can be produced by endophytic bacteria This study aims to identify seaweed endophytic bacteria (Turbinaria ornata, Sargassum crassifolium, Sargassum polycystum) and their potential antibacterial activity against skin disease agents (Staphylococcus aureus and Staphylococcus epidermidis). In February 2023 (the rainy season), seaweed was harvested from the waters off Panjang Island in Jepara Regency, Central Java, Indonesia. Endophytic bacterial isolates that had been effectively isolated and purified were directly tested for antibacterial activity. Three isolates with the best antibacterial activity were extracted using the ethyl acetate solvent. The extract samples will be put through additional antibacterial testing using the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and paper disc diffusion procedures. Using the thin layer chromatography (TLC), the class of chemical components in the extract was determined. A molecular technique based on the 16s rRNA gene (1,400 bp) was used to identify endophytic bacterial isolates. Three species of seaweed yielded 25 isolates of endophytic bacteria: 11 from T. ornata, 7 from S. crassifolium, and 7 from S. polycystum. To.09.pp, To.10.pp, and Sc.06.pp were the 3 isolates with the highest antibacterial activity in the direct challenge test. Zone of inhibition results from subsequent antibacterial testing using paper disc diffusion ranged from medium to very strong intensity. To.10.pp sample’s MIC test yielded the best results, with S. aureus and S. epidermidis concentrations of 937.5 and 1,875 µg/mL, respectively. MBC test yielded the highest findings, with S. aureus and S. epidermidis concentrations of 1,875 and 1,875 µg/mL, respectively. The To.10.pp sample yielded terpenoids, alkaloids, and flavonoids, according to TLC analysis of chemical constituent groups. Acinetobacter indicus strain 80-1-2 and Vibrio harveyi strain B14-1 were identified as potential endophytic bacteria from T. ornata, and Acinetobacter indicus strain 80-1-2 from S. crassifolium. HIGHLIGHTS Endophytic seaweed Turbinaria ornata, Sargassum crassifolium, and Sargassum polycystum showed antibacterial activity against Staphylococcus aureus ATCC 29213 and Staphylococcus epidermidis FNCC 0048 Acinetobacter indicus strain 80-1-2, and Vibrio harveyi strain B14-1 were all successfully identified by molecular analysis as potential endophytic bacteria Identification of compounds using Thin Layer Chromatography (TLC) showed the presence of terpenoids, alkaloids, and flavonoids GRAPHICAL ABSTRACT

GC-MS Spectrum of the Brown Alga, Turbinaria ornata (Turner) J Agardh and its Characterization of Bioactive Compounds

Seaweeds as a sustainable resource, possess numerous secondary metabolites which can alter insect metabolism, induce toxicity, modify growth, development and hinder their feeding activities. The purpose of the current study was to identify the bioactive compounds present in the acetone extract of brown algal seaweed, T. ornata and its biological activities. The phytochemical constituents were screened through Gas Chromatography and Mass Spectroscopy analysis which revealed the presence of 90 compounds that mostly comes under terpenoids, carboxylic acids, amino acids, saturated fatty acids, phenols and sesquiterpene at the retention time of 3.836, 7.398, 8.765, 15.897, 26.113, 31.636, 34.085, 35.276, 36.528 and 39.943. The identified compounds were likely to possess various biological activities such as antifungal, antibacterial, antioxidant and novel insecticidal properties proved its potential use in integrated pest management strategies in the future.

The potential accumulation of polycyclic aromatic hydrocarbons in macroalgae from the Egyptian coast of the Red Sea

In the marine environment, polycyclic aromatic hydrocarbons (PAHs) constitute one of the most pervasive and harmful types of organic pollutants. They pose an additional hazard to marine creatures' resilience due to ongoing climatic change. Therefore, determining their concentration and source is important for estimating their possible risks. Utilizing (GC–MS), we analyzed PAH levels in marine algal tissues along the Red Sea's Ras Gharib coastline. The present study covered the collection of seven Red Sea macroalgae namely; Sargassum cinereum, Caulerpa racemosa, Ulva intestinalisLinnaeus, 1753, Turbinaria ornata, Hormophysa cuneiformis, Ulva lactuca, and Cystoseira myrica) from the RasGharib coastline. Sixteen PAHs were found at quantities ranging from 159.67 to 261.57 ng/g in all of the examined marine algal tissues. The average concentration of the 16 PAHs was the highest in S. cinereum and the lowest in U. lactuca. The mean concentration of benzo(a)anthracene (BaA) in S. cinereum was 74.12 parts per billion (ng g−1). Two- and three-ringed PAHs with a lower molecular weight amounted to 2.51 to 23.54% of all PAH components in algal tissues. The average contribution of the eight cancer-causing PAHs to the total TEQcarc of the investigated species was sequentially as follows: BaP (50.23%), BaA (32.18%), BbF (6.52%), BkF (5.20%), IP (4.50%), and Chr (2.00%). The results of the diagnostic ratios demonstrated that the primary causes of most PAHs were combined pyrogenic and petrogenic activities. This suggests employing these indicators to investigate the biological impacts of PAHs pollution and establish its bioavailability in the marine environment.

Corallivory on small Porites colonies increases with coral colony size but is reduced by macroalgal associational refuge

Numerous tropical macroalgae provide associational refuge to other benthic organisms, presumably due to their physical structure and/or production of chemical metabolites. One feature determining their effectiveness as an associational refuge is likely to be the size of the organism benefitting from the refuge. Using a manipulative experiment in the back reef of Moorea, French Polynesia, we tested if the macroalga Turbinaria ornata provided an associational refuge from fish corallivores for small colonies of massive Porites spp., and how this differed with colony size (20–100 mm diameter). Tissue loss through corallivory increased with colony size but was ~ 72% less for Porites colonies associated with T. ornata versus colonies separated from this macroalga, while dense macroalgae beds on contemporary reefs negatively impact the recruitment, growth and survival of corals, small colonies of Porites appear to benefit, through reduced corallivory, by associating with the macroalga Turbinaria. This association may come at a cost (e.g., reduced growth) and should be the focus of future research.

Structural characterization, antioxidant and anti-uropathogenic potential of biogenic silver nanoparticles using brown seaweed Turbinaria ornata.

Alternative treatment strategies for urinary tract infections (UTIs) are becoming more necessary due to increasing drug resistance patterns in uropathogens. Nanoparticle-based therapeutics is emerging as a way to treat UTIs. In the present study, using Turbinaria ornata extract, silver nanoparticles (AgNPs) were synthesized, characterized, and their anti-uropathogenic activity was evaluated. The stability and formation of synthesized To-AgNPs were confirmed by UV-visible spectroscopy, FTIR, XRD, SEM, and DLS. An FTIR spectrum confirmed the presence of seaweed functional groups in To-AgNPs, a XRD analysis confirmed their crystalline nature, and SEM imaging confirmed their spherical nature with an average size of 73.98 nm with diameters ranging from 64.67 to 81.28 nm. This was confirmed by TEM results. DLS determined that the cumulant hydrodynamic diameter of To-AgNPs was 128.3 nm with a PdI of 0.313 and the zeta potential value were found to be -63.3 mV which indicates the To-AgNPs are negatively charged and more stable. DPPH assays were used to assess the antioxidant activity of biosynthesized To-AgNPs, while an agar well diffusion method was used to test the antibacterial activity against uropathogens, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Klebsiella pneumoniae. The To-AgNPs showed the highest susceptibility to S. aureus (15.75 ± 0.35 mm) and E. coli (15 ± 0.7 mm) with MIC values of 0.0625 and 0.125 mg/ml, respectively in macro broth dilution method and observed considerable membrane damage under CLSM and SEM. To-AgNPs displayed stronger antioxidant and antimicrobial activity, suggesting they may be developed as a new class of antimicrobial agents for treating UTIs.

Systematic study on the effect of seaweed fertilizer on the growth and yield of Vigna radiata (L.) R. Wilczek (Mung bean)

Seaweed (Marine algae) extracts have been reported to be beneficial to plants for early seed germination, better plant growth, improved crop yield, and also in preventing biotic and abiotic stress. They are naturally rich in plant growth-promoting factors like microelements, organic matter, vitamins, and fatty acids and can be a low-cost alternative to conventional N:P:K fertilizers and expensive organic farming techniques. Herein, the seaweed fertilizer (SF) have prepared by using three seaweeds, viz., Turbinaria ornata (TSF), Ulva intestinalis (USF), and Portieria hornemannii (PSF). The formulation was evaluated for biostimulant potential by performing a pot culture on Vigna radiata (L.) R. Wilczek, along with aqueous control, chemical fertilizer control (CFC), and organic manure control (OMC). The plants were treated with various groupings (individual and combination) of SF at six different concentrations. The study revealed that PSF (30%) stimulates maximum seed germination and an upsurge in plant growth (shoot length (28%), root length (120%), leaf count (53%), leaf area (62%), fresh weight (41%), and dry weight (54%)), pigment concentration (carotenoid (80%), chlorophyll a (29%), and chlorophyll b (41%)), and biochemical parameters of the leaves (carbohydrate (18%), protein (21%), amino acids (21%), phenolic content(49%)) when compared with aqueous control. The study revealed an 85% surge in the quantity of grains (15.568 g/plant) upon treatment with 30% PSF compared with aqueous control (8.413 g/plant). Followed by 30% (USF + PSF), 30% (TSF + PSF), and 40% PSF, have exhibited 75%, 73%, and 72% increase, respectively, compared with aqueous control. The nutrient uptake study exhibited that 30% PSF improves the efficiency of mineral uptake in V. radiata (L) plants. The results suggest that the tested SF, especially PSF, could be a low-cost and environmentally safe fertilizer. Based on this study, the formulated PSF could be used alone or partially replaced with commercial fertilizers to reduce the total cultivation cost.

Larvicidal effects of some natural products on the Aedes aegypti mosquito, a vector of dengue fever and Zika virus

AbstractNatural products are considered a good choice in the biological control of mosquitoes because they are an effective way to eliminate larvae and prevent an increase in mosquito numbers, while simultaneously not polluting the environment or damaging health. This investigation was designed to study the potential toxicity of three species of algae, Caulerpa racemosa (Weber‐van Bosse, 1909), Padina boryana (Thivy, 1966), and Turbinaria ornata (Turner J. Agardh, 1848), on the larvae of Aedes aegypti mosquito, the vector of dengue and Zika viruses. Among the studied species, Caulerpa racemosa showed the greatest effectiveness in eradicating A. aegypti larvae with an LC50 = 43.5 ppm, followed by Padina boryana with an LC50 = 51.93 ppm. Both species proved to be excellent candidates as a source of larvicidal agents and could be used commercially in mosquito control programs as eco‐friendly biopesticides. The combined activity of different mixtures against mosquito larvae was expressed as the coeffective factor (C.F.). C.F. values showed that the joint activity of insect growth regulator Dudim in combination with Caulerpa racemosa and Padina boryana extracts produced degrees of potentiation effects and degrees of additive effects were obtained with Dudim in combination with Turbinaria ornata extract.

Herbivory effects of sea urchin species on a coral reef (Bora-Bora, French Polynesia)

Macroalgae are becoming dominant on coral reefs worldwide, replacing corals as key habitat formers. Incrementing consumption rates by herbivores, such as sea urchins, has been identified as a viable strategy for promoting coral recovery. By means of a 28-day experiment, we assessed the grazing effects of the sea urchins, Tripneustes gratilla and Diadema setosum, on the macroalgal assemblages of shallow reefs at Bora-Bora (French Polynesia). In particular, each urchin species was either absent or maintained, using cages (n = 10), at a density of 5 individuals/m2. T. gratilla exerted stronger negative effects than D. setosum on all the examined macroalgae (i.e., Turbinaria ornata, Padina boryana, Halimeda spp, Dictyota spp). In addition, the grazing effects by T. gratilla on macroalgae emerged shortly after the start of the experiment, more rapidly than those of D. setosum. Despite an apparent lower food preference for T. ornata in D.setosum, all macroalgae were consumed by both species and the composition of the macroalgal assemblages (i.e., the proportion of each species) did not change after 28 days. Overall, our study suggests that herbivorous sea urchins, when at relatively high densities, could contribute to sustaining coral-dominance on coral reefs by keeping macroalgae under control.

Seasonal Changes in the Biochemical Composition of Dominant Macroalgal Species along the Egyptian Red Sea Shore

Macroalgae are significant biological resources in coastal marine ecosystems. Seasonality influences macroalgae biochemical characteristics, which consequentially affect their ecological and economic values. Here, macroalgae were surveyed from summer 2017 to spring 2018 at three sites at 7 km (south) from El Qusier, 52 km (north) from Marsa Alam and 70 km (south) from Safaga along the Red Sea coast, Egypt. Across all the macroalgae collected, Caulerpa prolifera (green macroalgae), Acanthophora spicifera (red macroalgae) and Cystoseira myrica, Cystoseira trinodis and Turbinaria ornata (brown macroalgae) were the most dominant macroalgal species. These macroalgae were identified at morphological and molecular (18s rRNA) levels. Then, the seasonal variations in macroalgal minerals and biochemical composition were quantified to determine the apt period for harvesting based on the nutritional requirements for commercial utilizations. The chemical composition of macroalgae proved the species and seasonal variation. For instance, minerals were more accumulated in macroalgae C. prolifera, A. spicifera and T. ornata in the winter season, but they were accumulated in both C. myrica and C. trinodis in the summer season. Total sugars, amino acids, fatty acids and phenolic contents were higher in the summer season. Accordingly, macroalgae collected during the summer can be used as food and animal feed. Overall, we suggest the harvesting of macroalgae for different nutrients and metabolites in the respective seasons.

Differential photosynthetic, phytochemical and antioxidative responses of three macroalgae Ulva lactuca, Gracilaria salicornia and Turbinaria ornata exposed to thermal and irradiance conditions

Abstract. Narrain D, Baulroop J, Bhagooli R, Bahorun T. 2023. Differential photosynthetic, phytochemical and antioxidative responses of three macroalgae Ulva lactuca, Gracilaria salicornia and Turbinaria ornata exposed to thermal and irradiance conditions. Indo Pac J Ocean Life 7: 1-15. Worldwide climate change leads to a varied distribution of aquatic organisms due to their differences in susceptibility to environmental conditions. Being at the base of marine food webs, macroalgae are potential candidates to investigate the effects of changing environmental conditions and to study the adaptation mechanisms. This study examined the effects of in vitro thermal and irradiance conditions (Control - CLCT: 1.55±0.63 µmol quanta m-2s-1 and 28°C; Control light and high temperature - CLHT: 1.55±0.63 µmol quanta m-2s-1 and 32°C; Moderate light and control temperature – MLCT: 100±63.6 µmol quanta m-2s-1 and 28°C; Moderate light and high temperature – MLHT: 100±63.6 µmol quanta m-2s-1 and 32°C) for 1 week on the photosynthetic performance, phytochemical contents, and antioxidant potential of three macroalgae Ulva lactuca L., Gracilaria salicornia (C.Agardh) E.Y.Dawson and Turbinaria ornata (Turner) J.Agardh found in the lagoons of Mauritius Island. Our results indicate variable responses of the three test macroalgal species when exposed to combinations of temperature and light conditions. Differential responses were found to be both species- and stress-specific. Chlorophyll fluorescence measurements using a Diving Pulse-Amplitude Modulated (D-PAM) fluorometer indicated a significant increase (p<0.001) in relative maximum electron transport rate (rETRmax) of U. lactuca in all stress treatments implying higher photosynthetic activity compared to control conditions. A significant decrease (p<0.001) in rETRmax of G. salicornia under MLHT and the collapse of photosystem II (PSII) activity (Fv/Fm) in T. ornata, along with both species exhibiting visual pigment degradation, are suggestive of chronic photo-inhibition in these two macroalgal species. Antioxidant activities (FRAP and TEAC assays) correlated stronger to flavonoid contents (FRAP, r=0.909; TEAC, r=0.845) than to phenol contents (FRAP, r=0.688; TEAC, r=0.758). An increase in temperature and irradiance severely damaged the PSII of T. ornata and G. salicornia, while U. lactuca could photo-physiologically adjust to changing environmental conditions, showing its robustness. The elevated temperature significantly affected the photosynthetic performance and antioxidative activities of the tested macroalgal species (p<0.001). These findings are discussed to possible influence on defense mechanisms of these macroalgal species and their aquaculture potential in an era of climate change. Further research using field-based manipulations as well as molecular analysis is warranted to thoroughly understand the potential mechanisms involved in variable responses of these tested macroalgae.

Diversity and Distribution of Phaeophyta Macroalgae in Pedalen Coastal Waters, Kebumen

Pedalen Beach, Kebumen, has a type of water substrate consists of sand, coral fragments, and coral overgrown with macroalgae. This study aims to determine the species diversity and distribution pattern of Phaeophyta found in that waters. This research is to explore and utilize macroalgae as a sustainable alginate resource. This study uses a survey method, employing the line transect method randomly. The research variables were species diversity and the distribution pattern of Phaeophyta. The main parameters were the number of species and individuals of each species. Supporting parameters include current velocity, nitrate content, brightness, depth, tide, salinity, temperature, and pH. The data were analyzed using the Shannon-Wiener diversity index (H’) to determine the level of species diversity and the Morisita distribution index (Id) to describe the distribution pattern of macroalgae species. We found five Phaeophyta species consisting of Padina australis, Dictyota dichotoma, Turbinaria ornata, Sargassum crassifolium, and S. polycystum. The diversity of Phaeophyta is classified as low diversity index value (H’) with distribution patterns of uniform macroalgae species. The results of the measurement of physical and chemical factors of the waters showed that the condition of the Pedalen Beach waters was quite good for the growth of Phaeophyta.
 
 Keywords: alginate, macroalgae species, Phaeophyta, water substrate

Ontogenetic Variation in Blade Toughness May Contribute to the Spread of Turbinaria ornata Across the South Pacific.

Coral reefs are shifting from coral to algal-dominated ecosystems worldwide. Recently, Turbinaria ornata, a marine alga native to coral reefs of the South Pacific, has spread in both range and habitat usage. Given dense stands of T. ornata can function as an alternative stable state on coral reefs, it is imperative to understand the factors that underlie its success. We tested the hypothesis that T. ornata demonstrates ontogenetic variation in allocation to anti-herbivore defense, specifically that blade toughness varied nonlinearly with thallus size. We quantified the relationship between T. ornata blade toughness and thallus size for individual thalli within algal stands (N=345) on seven fringing reefs along the north shore of Moorea, French Polynesia. We found that blade toughness was greatest at intermediate sizes that typically form canopies, with overall reduced toughness in both smaller individuals that refuge within the understory and older reproductive individuals that ultimately detach and form floating rafts. We posit this variation in blade toughness reduces herbivory on the thalli that are most exposed to herbivores and may facilitate reproduction in dispersing stages, both of which may aid the proliferation of T. ornata.