Marine Macroalgae Research Articles

Hydrothermal treatments – A quick and efficient alternative for agar extraction from Gelidium sesquipedale

The red seaweed Gelidium sesquipedale is recognized for its high-quality agar, a valued hydrocolloid with gelling capacity, an industrially desirable property strongly dependent on its structure and composition. Despite its importance, there is a lack of information regarding the effects of processing conditions, including alternative extraction technologies, on these properties. To shorten that gap, the present study aimed to evaluate the use of autohydrolysis for obtaining agar from this marine macroalgae. This was performed by assessing the effect of hydrothermal treatments' severity and time and temperature binomials (at the same severity factor) on the extraction yield, texturizing and rheological behaviour, structure, composition, and molecular weight of the polysaccharide. The results obtained indicated that the optimal processing severity for agar recovery is 2.1 ± 0.1. Not only does this condition preserve the extraction yield (ranging from 12.3 ± 3.4% to 23.4 ± 1.6%, depending on the time and temperature binomial chosen), but it also results in a gelling strength of 758 ± 44 g/cm 2 , all while allowing a sharp processing time reduction (e.g. 1 min at 150 °C and 7.5 min at 140 °C). Molecular weight, rheological behaviour, and texturizing capacity proved to be directly linked to treatment's severity, with no differences observed in time and temperature binomials (at the same severity factor). On the other hand, 3,6-anhydro-α- l -galactose content and overall structure appeared to be intrinsic to the biomass, and not affected by the extraction conditions. Overall, this work demonstrated that autohydrolysis can be used to quickly and efficiently obtain high-grade food-safe agars when properly tuned. • Autohydrolysis can be applied for the extraction of agars from Gelidium sesquipedale . • Autohydrolysis allows for a reduction in high gel strength agar extraction time. • A hydrothermal treatment with 2.1 severity is optimal for agar's gelling strength. • At equal severity, time and temperature combinations do not impact the agars' traits. • Treatment's severity influences the composition, structure and behaviour of agars.

Antioxidant and anti-photoaging properties of red marine macroalgae: Screening of bioactive molecules for cosmeceutical applications

Oxidative stress generated by UV exposition plays an important role on photoaging. Understanding the cell physiological responses due to the action of oxidative molecules process helps to develop approaches to reduce its impact on skin cells. In this context, algae can be source of biomolecules with antioxidant, inhibition of metalloproteinases and photoprotective capacities, such as mycosporine-like amino acids and phenolic compounds. This study focuses on the characterization of aqueous and hydroethanolic extracts of six red marine macroalgae: Phycocalidia acanthophora, Porphyra linearis, Condracanthus teedei, Gracilaria cornea, Osmundea pinnatifida and Plocamium cartilagineum (from two different sites). Besides their biochemical characterization, we also evaluated antioxidant capacity, potential to collagenase inhibition, and photoprotective capacity by different biological effective protection factors (BEPFs). Results evidenced a better correlation among the compounds of interest and bioactivity when using water as solvent rather than hydroethanolic solution. P. acanthophora and P. linearis aqueous extracts were highlighted in all analyses. Considering this fact, these two extracts were incorporate onto a cosmeceutical formulation. BEPFs evidenced that the incorporation of the extracts increased the photoprotection factors when compared to the control without physical filters. According to the findings herein described, the potential of red macroalgae as source of bioactive compounds with antiaging potential is reinforced.

A Critical Comparison of the Advanced Extraction Techniques Applied to Obtain Health-Promoting Compounds from Seaweeds.

Marine macroalgae are rich in bioactive compounds that can be applied in several fields, mainly food, cosmetics, and medicine. The health-promoting effects of bioactive compounds, such as polyphenols, polysaccharides, carotenoids, proteins, and fatty acids, have been increasingly explored, especially regarding their antioxidant activity and improvement in human health. To extract these valuable compounds, advanced technologies that include Supercritical-Fluid Extraction (SFE), Pressurised-Liquid Extraction (PLE), Ultrasound-Assisted Extraction (UAE), Microwave-Assisted Extraction (MAE), Enzyme-Assisted Extraction (EAE), Ultrasound-Microwave-Assisted Extraction (UMAE) and Liquefied Gas Extraction (LGE) have been assessed due to their notable advantages over the conventional methods (Solid-Liquid and Soxhlet extraction). These advanced techniques are considerably influenced by different extraction parameters such as temperature, pressure, type of solvent, extraction time, solvent:solid material ratio, power (MAE, UAE, and UMAE), enzymes used (EAE), and factors related to the macroalgae matrix itself. Optimizing these process parameters for each method is critical to obtain better efficiency results for the targeted bioactive compounds. Macroalgae are natural sources with undeniable beneficial effects on human health. In this context, optimising the extraction techniques discussed in this review should prioritise exploiting these valuable resources' wide range of bioactive properties.

Effects of various macroalgae species on methane production, rumen fermentation, and ruminant production: A meta-analysis from in vitro and in vivo experiments

A meta-analysis was performed to examine the dietary inclusion of marine macroalgae species to target methane (CH4) reduction from ruminant animals and the effects on rumen fermentation and animal performance. A literature search was conducted from global scientific databases, resulting in 25 in vitro and 22 in vivo studies eligible to be integrated in a database. A total of 673 experimental units comprising 537 in vitro and 136 in vivo experimental units were analyzed by using mixed model methodology in SAS and multivariate analysis in R Studio. Principal component analysis (PCA) from in vitro dataset revealed difference effects of brown, green, and red macroalgae on CH4 production without a pronounced pattern on rumen fermentation. Likewise, PCA from in vivo dataset supported the in vitro results whereas Ascophyllum nodosum (brown) and Asparagopsis taxiformis (A. taxiformis; red) species showed noticeably separated clusters on CH4 production. Mixed regression analysis from in vitro and in vivo databases showed interaction effects (P < 0.001) between levels × species on CH4 production and the percentages of acetate (C2), propionate (C3), butyrate (C4) whereas A. taxiformis showed the greatest effects on the decrease of C2 and increase of C3 proportions (P < 0.001), among other species. Additionally, dietary levels of A. taxiformis had strong linear decrease (R2= 0.946; P < 0.001) on CH4 (g/d) and curvilinear effect on CH4 when expressed as g/kg DMI (R2= 0.687; P < 0.001). When considering the types of animals, A. taxiformis decreased (P < 0.001) CH4 by 64.76 % in beef cattle but the effect in dairy cows and small ruminant were non-significant (P > 0.05) compared with control diet as a reference. Curvilinear effect on in vitro organic matter digestibility (P = 0.043) and linear degreased on crude protein digestibility (P = 0.029) were found. Feeding macroalgae did not affect dry matter intake (DMI), average daily gain (ADG), milk production and milk composition except for milk lactose which linearly increased (R2= 0.731; P = 0.002) by increasing Ascophyllum nodosum level. In dairy cows, the inclusion of A. taxiformis increased iodine concentration by more than six-fold increase (P < 0.001) while other species had no substantial effect on iodine concentration. Taken together, macroalgae can be used as feed ingredients for ruminants to decrease CH4 emissions without detrimental effects on metabolism and production performance in ruminant livestock. Notwithstanding, feeding A. taxiformis > 10 g/kg DM of diet may result in an unfavorable effect on the high bromoform and iodine residuals in milk. Future in vivo study using less-explored species that had been tested in vitro need to be conducted.

A novel anti-hyperglycemic sulfated pyruvylated polysaccharide from marine macroalga Hydropuntia edulis

Dipeptidyl peptidase is a crucial enzyme that regulates glucose metabolism by degrading incretins, such as glucagon-like-peptide-1, thereby reducing insulin secretion from the pancreatic β-cells. Consequently, dipeptidyl peptidase-IV inhibitors are an important remedial approach to moderate the hyperglycemic pathophysiology. A pyruvylated polysaccharide characterized as [→3)-4,6-O-(1-carboxyethylidene)-β-D-galp-(2SO3 −)-(1→4)-3,6-α-L-AnGalp-(2OMe)-(1→], isolated from the marine macroalga Hydropuntia edulis, showed attenuation potential against dipeptidyl peptidase-IV (IC50 4.44 μM). The structure was elucidated using mass and one/two-dimensional nuclear magnetic resonance spectroscopic analyses of hydrolyzed polysaccharide besides glycosidic linkages obtained from partially methylated alditol acetate derivative. The isolated polysaccharide also revealed potential anti-carbolytic properties against α-amylase/α-glucosidase (IC50 45–47 μM). The results proved the candidacy of pyruvylated polysaccharide isolated from H. edulis as a potential therapeutic lead against hyperglycemia.

A Demonstration of DNA Barcoding-Based Identification of Blade-Form Ulva (Ulvophyceae, Chlorophyta) Species from Three Site in the San Juan Islands, Washington, USA

Marine macroalgae are foundation species that play a critical ecological role in coastal communities as primary producers. The macroalgal genus Ulva is vital in intertidal communities, serving as a food source and shelter for organisms, but these species also form environment-damaging nuisance blooms. This project aimed to demonstrate the utility of DNA barcoding for determining the diversity of Ulva species in the San Juan Islands (Washington, DC, USA). Blade-form Ulva (Ulvophyceae) specimens were collected from the lower, mid, and upper intertidal zones at three sites experiencing different levels of wave exposure. Sequences of plastid-encoded tufA were generated for each specimen and cluster analyses revealed the presence of four species at the collection sites. Two species were positively identified as Ulva expansa and Ulva fenestrata based on their sharing identical tufA sequences with those of the holotype specimens. Sequences of plastid-encoded rbcL and the nuclear-encoded ribosomal ITS regions of representative specimens were used to identify the other two species as Ulva prolifera and Ulva californica based on their similarity to epitype and topotype specimen sequences, respectively. Additional types of specimen sequencing efforts are needed to increase the number of Ulva species that can be accurately identified and realize their true biodiversity.

Morphological changes and biochemical reaction of Ulva rigida in response to the toxic effect of bisphenol A under experimental conditions

The large-scale worldwide production and consumption of bisphenol A (BPA) has resulted in the ubiquitous presence of this chemical in aquatic ecosystems. Primary producers such as marine macroalgae can be successfully used for monitoring in order to determine the environmental risk from organic pollutants. The article is based on new experimental data obtained by the authors in the study of the sensitivity of the green marine benthic algae Ulva rigida to the impact of various concentrations of BPA was conducted. Exposure to BPA led to structural and functional changes in the Ulva samples: growth rate, cell size, and photosynthetic pigment content. In concentrations from 40 to 100 mg/L, a destructive effect from BPA on the Ulva was observable within 24–48 h, taking the form of complete chloroplast discoloration occurring in 100% of its cells. A dose-dependent stimulating effect of low concentrations of BPA on the growth of Ulva was also noted. As compared with the control, the disc area of Ulva in a medium with a BPA concentration of 0.1 mg/L almost doubled within 30 days, while at 5 mg/L, it increased by only 21%. Changes in chlorophyll a and b content were observed in the first hours of BPA exposure. The pigment content in the Ulva decreased under the influence of BPA both at an impact concentration of 100 mg/L and a low concentration of 0.01 mg/L. The sensitivity to bisphenol А contamination of the U. rigida in different regions may vary.

Chemo-Sonic Pretreatment Approach on Marine Macroalgae for Energy Efficient Biohydrogen Production

The core objective of this analysis is to implement a combination of alkaline (NaOH) and sonication pretreatment techniques to produce energy-efficient biohydrogen from the marine macroalgae Chaetomorpha antennina. Anaerobic fermentation was implemented in control, sonic solubilization (SS) and sonic alkali solubilization (SAS) pretreatment for 15 days. In control, a biohydrogen production of 40 mL H2/gCOD was obtained. The sonicator intensities varied from 10% to 90% for a period of 1 h during SS pretreatment. About 2650 mg/L SCOD release with a COD solubilization of 21% was obtained at an optimum intensity of 50% in a 30 min duration, in which 119 mL H2/gCOD biohydrogen was produced in the anaerobic fermentation. SAS pretreatment was performed by varying the pH from 8 to 12 with the optimum conditions of SS where a SCOD release of 3400 mg/L, COD solubilization efficiency of 26% and a maximum biohydrogen production of 150 mL H2/gCOD was obtained at a high pH range of 11 in the fermentation. The specific energy required by SS (9000 kJ/kgTS) was comparatively higher than SAS (4500 kJ/kg TS). SAS reduced half of the energy consumption when compared to SS. Overall, SAS pretreatment was found to be energetically favorable in a field application.

Prospects of dietary seaweeds and their bioactive compounds in sustainable poultry production systems: A symphony of good things?

Modern poultry production systems face numerous economic, environmental, and social sustainability challenges that threaten their viability and acceptability as a major source of animal protein. As scientists and producers scramble to find cost-effective and socially acceptable solutions to these challenges, the dietary use of marine macroalgae (seaweeds) could be an ingenious option. Indeed, the incredible array of nutritive and bioactive compounds present in these macroscopic marine organisms can be exploited as part of sustainable poultry production systems of the future. Incorporating seaweeds in poultry diets could enhance feed utilization efficiency, growth performance, bird health, meat stability and quality, and consumer and environmental health. Theoretically, these benefits are mediated through the putative antiviral, antibacterial, antifungal, antioxidant, anticarcinogenic, anti-inflammatory, anti-allergic, antithrombotic, neuroprotective, hypocholesterolemic, and hypoglycemic properties of seaweed bioactive compounds. Despite this huge potential, exploitation of seaweed for poultry production appears to be constrained by a variety of factors such as high fibre, phenolics, and ash content. In addition, conflicting findings are often reported when seaweeds or their extracts are used in poultry feeding trials. Therefore, the purpose of this review paper is to collate information on the production, phytochemical components, and nutritive value of different seaweed species. It provides an overview ofin vivoeffects of dietary seaweeds as measured by nutrient utilization efficiency, growth performance, and product quality and stability in poultry. The utility of dietary seaweeds in sustainable poultry production systems is explored, while gaps that require further research are highlighted. Finally, opportunities that exist for enhancing the utility of seaweeds as a vehicle for sustainable production of functional poultry products for better global food and nutrition security are presented.

A Genomics Resource for 12 Edible Seaweeds to Predict Seaweed-Secreted Peptides with Potential Anti-Cancer Function.

Simple SummaryEdible seaweed, also known as sea vegetables, are macroalgae that can be eaten and used in cooking. They contain enriched bioactive compounds such as polysaccharides, which have a variety of functions such as antioxidants, anti-aging, and immune regulation. This study was a voyage of biological discovery that sought to thoroughly examine all of the DNA (known as a genome) of 12 edible seaweeds. The collected genomic sequence data are publicly accessible as a critical functional reference for the discovery of bioactive products and genome-assisted breeding for edible seaweeds. Secreted proteins frequently circulate throughout the body and, thus, have access to the majority of organs and tissues in animals. We investigate the potential secreted short peptides in seaweed using a comparative analysis of protein families that interact with human cancer genes. Some of the secreted proteins may be therapeutic agents interacting with surface receptors in human cells due to their circulating function. In summary, our data integration predicted the first shortlist of secreted peptides of edible seaweeds, which may provide novel information about anti-tumour mechanisms, thus accelerating the study of seaweed biology and improving seaweed nutraceutical practice.Seaweeds are multicellular marine macroalgae with natural compounds that have potential anticancer activity. To date, the identification of those compounds has relied on purification and assay, yet few have been documented. Additionally, the genomes and associated proteomes of edible seaweeds that have been identified thus far are scattered among different resources and with no systematic summary available, which hinders the development of a large-scale omics analysis. To enable this, we constructed a comprehensive genomics resource for the edible seaweeds. These data could be used for systematic metabolomics and a proteome search for anti-cancer compound and peptides. In brief, we integrated and annotated 12 publicly available edible seaweed genomes (8 species and 268,071 proteins). In addition, we integrate the new seaweed genomic resources with established cancer bioinformatics pipelines to help identify potential seaweed proteins that could help mitigate the development of cancer. We present 7892 protein domains that were predicted to be associated with cancer proteins based on a protein domain–domain interaction. The most enriched protein families were associated with protein phosphorylation and insulin signalling, both of which are recognised to be crucial molecular components for patient survival in various cancers. In addition, we found 6692 seaweed proteins that could interact with over 100 tumour suppressor proteins, of which 147 are predicted to be secreted proteins. In conclusion, our genomics resource not only may be helpful in exploring the genomics features of these edible seaweed but also may provide a new avenue to explore the molecular mechanisms for seaweed-associated inhibition of human cancer development.

75P Biosynthesis and characterization of selenium nanoparticles using marine algae Sargassum wightii: Understanding its anticancer activity through ROS-mediated p53 and Akt signaling pathways in A549 cells

75P Biosynthesis and characterization of selenium nanoparticles using marine algae Sargassum wightii: Understanding its anticancer activity through ROS-mediated p53 and Akt signaling pathways in A549 cells

Effect of Heating Coarse Extract of Brown Macroalgae (Padina australis) from Tial Waters, Salahutu District, Central Maluku Regency on Antioxidant Activity

Physical and chemical factors influence antioxidant activity. One of the physical factors that can affect antioxidant activity is heat. This study aims to determine the phytochemical content and the effect of heating the crude extract of marine macroalgae Padina australis on antioxidant activity. The research method used, namely maceration using methanol as a solvent to obtain a crude extract, then evaporation of the solvent at a temperature of 45 °C. Furthermore, phytochemical tests were carried out, characterization using TLC and UV-Vis spectrophotometer, and determination of free radical scavenging activity of DPPH. The results of the phytochemical test showed that the crude extract of Padina australis was positive for bioactive compounds, namely saponins, alkaloids, terpenoids, steroids, and flavonoids. Characterization by TLC and UV-Vis spectrophotometer showed the presence of secondary metabolites, namely chlorophyll a and carotenoids. The use of temperature in the solvent evaporation process affects the stability of bioactive compounds and secondary metabolites. The results of the antioxidant activity test (IC50) of the crude extract of Padina australis against DPPH obtained 163 ppm, so it is classified as an antioxidant in the medium category.

Characterization and Bioactivity of Polysaccharides Separated through a (Sequential) Biorefinery Process from Fucus spiralis Brown Macroalgae.

Marine macroalgae biomass is a valuable renewable resource that can be used for the development of bioeconomy through the valorisation of valuable compounds. The aim of the current study is separate macroalgal polysaccharides with bioactive properties from brown macroalgae Fucus spiralis based on a designed biocascading biorefinery approach. Thus, we applied an integrated processing method for the separation of fucoidan and alginate, in addition to characterization through IR spectroscopy and 1H NMR. The bioactivity potential (antioxidant activity using superoxide anion and DPPH radical scavenging analysis) of the two polysaccharides was evaluated, together with DNA binding studies performed though voltametric techniques and electronic spectroscopy titration. In terms of results, functional groups S=O (1226 cm−1), N=S=O (1136 cm−1) and C-O-SO3 (1024 cm−1), which are characteristic of fucoidan, were identified in the first polysaccharidic extract, whereas guluronic units (G) (1017 cm−1) and mannuronic units (M) (872 and 812 cm−1) confirmed the separation of alginate. The DNA binding studies of the isolated polysaccharides revealed an electrostatic and an intercalation interaction of DNA with fucoidan and alginate, respectively. Both antioxidant activity assays revealed improved antioxidant activity for both fucoidan and alginate compared to the standard α-tocopherol.

Preliminary Phytochemical and GC-MS Analysis of Marine Seaweed-Acoathophora deilei (Red alga)

Background: Seaweeds (Marine macro algae) are multicellular marine organism and are vital constituents of the of marine ecosystem, which are abundant in the coastal areas of the world. They are tremendous source of many bioactive metabolites and have been shown to exhibit a wide range of therapeutic properties, including anti-cancer, anti-oxidant, anti-inflammatory and anti-diabetic activities. Several Asian cultures have a strong tradition of using different varieties of seaweed extensively in cooking as well as in herbal medicines preparations. As such, seaweeds have been used to treat a wide variety of health conditions such as cancer, digestive problems, and renal disorders. These plants contain important phytochemical constituents and have various potential biological activities. References regarding the use of algae in Ayurveda and Siddha system of medicine has been reported since time immemorial, but their phytochemical properties have not been reported. Aim: To identify the phytochemical constituents present in the Acoathophora deilei (Red alage) using Preliminary phytochemical and GC-MS analysis. Methods: The shade-dried of red algae were extracted with methanol and the crude methanolic extract was subjected to GC-MS analysis to identify the various bioactive components Results: Phytochemical investigations suggests that the Acoathophora deilei showed the presence of phytochemicals like alkaloids, phytosterols, flavonoids and diterpenes, which may contribute to its biological activities. GC-MS analysis showed the presence of 28 different compounds. The main chemical constituents found in high percentage are Hexadecanoic acid methyl ester, 2-ethyl butyric acid octadecyl ester, hexadecanoic acid, 9-octadecanoic acid methyl ester and 1,2 – Benzene dicarboxylic acid. Conclusion: Thus, the present analytical study of Acoathophora deilei on phytochemical and GC-MS analysis provides an important novel information to support further ongoing studies to evaluate structure of bioactive compound and its pharmacological activities.

Taxol and β-tubulins from endophytic fungi isolated from the Himalayan Yew, Taxus wallichiana Zucc.

Paclitaxel, better known as the anticancer drug Taxol®, has been isolated from several plant species and has been shown to be produced by fungi, actinomycetes, and even bacteria isolated from marine macroalgae. Given its cytostatic effect, studies conducted in the 1990's showed that paclitaxel was toxic to many pathogenic fungi and oomycetes. Further studies led to the idea that the differences in paclitaxel sensitivity exhibited by different fungi were due to differences in the β-tubulin protein sequence. With the recent isolation of endophytic fungi from the leaves and bark of the Himalayan Yew, Taxus wallichiana Zucc., and the availability of genomes from paclitaxel-producing fungi, we decided to further explore the idea that endophytic fungi isolated from Yews should be well-adapted to their environment by encoding β-tubulin proteins that are insensitive to paclitaxel. Our results found evidence of episodic positive/diversifying selection at 10 sites (default p-value threshold of 0.1) in the β-tubulin sequences, corresponding to codon positions 33, 55, 172, 218, 279, 335, 359, 362, 379, and 406. Four of these positions (i.e., 172, 279, 359, and 362) have been implicated in the binding of paclitaxel by β-tubulin or formed part of the binding pocket. As expected, all the fungal endophytes grew in different media regardless of the paclitaxel concentration tested. Furthermore, our results also showed that Taxomyces andreanae CBS 279.92, the first fungus shown to produce paclitaxel, is a Basidiomycete fungus as the two beta tubulins encoded by the fungus clustered together with other Basidiomycete fungi.

Thermogravimetric Analysis of Marine Macroalgae Waste Biomass as Bio-Renewable Fuel

Macroalgae are considered as the 3rd generation of biofuels and a future feedstock for biorefinery. This research aims to provide simple and dependable analytical techniques for measuring the thermal characteristics of dried seaweed. The main objective was to investigate the thermal characteristics of four seaweed species utilizing a thermogravimetric analyzer. The seaweeds Gracilaria fisheri, Caulerpa lentillifera, Ceramium rubrum, and Eucheuma cottonii were collected from the Pahang state of Peninsular Malaysia. The calorific value of the samples was revealed by using a calorimeter. Ceramium rubrum showed the highest calorific value, while Gracilaria fisheri had the most negligible calorific value among the selected samples. The thermogravimetric analysis (TGA) data revealed that the most significant weight loss for this biomass occurred between 160 and 300° for the selected species. Gracilaria fisheri has shown the highest decomposition with the minor residue at 30.26%, whereas Caulerpa lentillifera has a slow weight loss rate in the mentioned range. SEM analysis has been used to perform the morphology of samples, which shows differences in the concentration of epiphytic diatoms with different structural shapes. Based on the results, macroalgae is a promising sustainable biomass feedstock for biofuel application.

Non-calcified warm-water marine macroalgae from the Ordovician strata of Spiti, Tethys Himalaya, India

The calcareous siltstones within the Ordovician section of the Takche Formation near Takche, Spiti region of Tethyan Himalaya, India, contain numerous specimens of non-calcified marine macroalgae in association with brachiopods, gastropods, tentaculitoids, and few trace fossils. The algal remains, representing five genera, are preserved as black or dark brown carbonaceous compression fossils, interpreted as warm-water marine macroalgae, namely, Inocladus sp., Callisphenus? sp., Algites sp. (siphonous algae), Fisherites sp., and Mastopora sp. (non-siphonous). Callisphenus is characterised by a radially symmetrical short pyriform thallus, with a central axis surrounded by short laterals whereas Inocladus sp. is characterised by an unsegmented simple thallus with internal parallel medullary siphons and cortical tubes. These algal remains, probably transported from a more near-shore living niche, co-occur with Cyclocrinitids, Tentaculitoids tube worms, trace fossils and brachiopods, suggesting that deposition of the studied units took place in low energy hydrodynamic conditions influenced by intermittent storm events. The study represents the first diversified macroalgal records from the Ordovician strata in the Tethyan realm of Indian subcontinent.

Effects of diluted seawater on the growth, antioxidation capacity and accumulation of bioactive compounds of the brown alga, Sargassum muticum

Environmental condition is a significant factor that directly affects the growth, metabolism and productivity of marine algae. This study examined the influences of diluted seawater on the growth, antioxidation capacity and accumulation of bioactive compounds of the marine macroalga, Sargassum muticum. Compared to the natural seawater (30 ppt, parts per thousand) control, the specific growth rate was clearly elevated at diluted seawater with 15 and 20 ppt during the initial 3 days, and was not statistically different at diluted seawater from 15 to 30 ppt at 15 days, while it decreased significantly at a low seawater concentration of 10 ppt. Chlorophyll a, carotenoids and total protein content fluctuated slightly under the different seawater solutions, suggesting that the algal cells underwent metabolic regulation during the period of adaptation to culture media changes. Changes in seawater concentration altered antioxidant enzyme activity, for instance, total superoxide dismutase, catalase and peroxidase, especially at low seawater solutions with 10 and 15 ppt. The malondialdehyde content also increased substantially, indicating that oxidative damage occurred in diluted seawater below 15 ppt. Moreover, the alginate content increased with decreasing seawater concentration, the alginate productivity was significantly increased by 22.32%–54.79% in all dilutions at 3 days and this promotion continued only at 15 and 20 ppt salinities after 7 days. The fucoxanthin content reduced significantly in the 10 and 15 ppt dilutions at 15 days, however, its productivity increased slightly at 10 and 15 ppt salinities in the first 3 days. The phlorotannin content increased slightly in the seawater dilutions with 20 ppt at 3 and 7 days, meanwhile, its productivity was significantly elevated during the initial 3 days at all seawater dilutions and the highest value was found at 20 ppt treatment. These results provide valuable data for the development and management of the aquaculture of S. muticum.

Fucoidan from Marine Macroalgae: Biological Actions and Applications in Regenerative Medicine, Drug Delivery Systems and Food Industry.

The marine macroalgae produce a collection of bioactive polysaccharides, of which the sulfated heteropolysaccharide fucoidan produced by brown algae of the class Phaeophyceae has received worldwide attention because of its particular biological actions that confer nutritional and health benefits to humans and animals. The biological actions of fucoidan are determined by their structure and chemical composition, which are largely influenced by the geographical location, harvest season, extraction process, etc. This review discusses the structure, chemical composition and physicochemical properties of fucoidan. The biological action of fucoidan and its applications for human health, tissue engineering, regenerative medicine and drug delivery are also addressed. The industrial scenario and prospects of research depicted would give an insight into developing fucoidan as a commercially viable and sustainable bioactive material in the nutritional and pharmacological sectors.

Halimeda gracilis (Kadarpassi chooranam) Phytochemical analysis and biological significance- a novel Siddha drug.

To evaluate biological activity and the phytochemical analysis of kadarpassi chooranam. Seaweeds are the marine macro algae, species belonging to Protista kingdom that has no true system, internal vascular systems, seeds and flowers. It has a lot of biological activity and has been proven to have a lot of medicinal benefits. Since time immemorial, their usage in traditional medicine has been recognized. Halimeda gracilis has been standardized as per siddha pharmacopoeia standard protocol guidelines and prepared kadarpassi Chooranam curtained for Phytochemical analysis (qualitative and quantitative) and carried out various pharmacological activity. The antioxidant, anti-inflammatory, and anti-cancer actions of kadarpassi Chooranam have been associated to alkaloids, phenols, flavonoids, cardiac glycosides, saponins, tannins, and diterpenes. The Siddha medicine, kadarpassi chooranam has various phytochemical bioactive compounds, and because of its pharmacological activity can be a potential drug candidate for human use.