Ameliorating drought stress in sugarcane (Saccharum spp.) using biostimulants

In India, abiotic stress, particularly drought, is known to affect sugarcane cultivation. Among various management strategies, application of biostimulants, especially those from seaweeds, offer promising results in containing yield loss due to drought stress. Here, we tested the efficacy of Sea6 liquid biostimulant formulation LBS6 in field condition along with conventional management practices for comparison purpose using two popular commercial varieties of sugarcane (Co 86032 and Co 0212). Drought stress imposed during formative phase of the crop and foliar application of sea6 liquid formulation was applied at 60, 90 and 120 days after planting (DAP). The effect of liquid formulation on mitigating drought stress was assessed by studying the growth, physiological, yield and yield traits at important pheno-phases of the crop. Results showed that, in Co 86032 shoot population of control was 100.5×103 ha-1 and drought was 85.1×103 ha-1 with mean reduction of 15.5% over control. Drought stress induced 11.4, 12.4, 9.8 and 5.0% reduction in plant height, leaf area index (LAI), chlorophyll content (SPAD value) and photochemical efficiency, respectively. In Co 0212, drought induced 10.15, 9.4, 10.5, 9.5 and 5.1% reduction in shoot population, plant height, LAI, SPAD value and photochemical efficiency, respectively. Under drought condition, in Co 86032, foliar application of KCl (2.5%) and seaweed extract LBS6(2 mL L-1) was observed comparatively higher cane yield of 92.9 t ha-1 and 89.5 t ha-1, with 18 and 16.5% yield improvement over untreated drought plot, respectively. In Co 0212, foliar application of KCl (2.5%) and seaweed extract LBS6 (2 mL L-1) recorded 99 and 93.5 t ha-1 with 18.5% and 15.2% yield improvement over untreated drought plot, respectively. Among the two varieties, Co 0212 performed better under drought situation with KCl (2.5%) spray demonstrating better physiological efficiency under stress, closely followed by of sea6 formulation LBS6 (2 mL L-1). Further, the drought management practices did not affect the juice quality parameters in both the tested varieties.

Gracilaria fisheri oligosaccharides ameliorate inflammation and colonic epithelial barrier dysfunction in mice with acetic acid-induced colitis

Objective: To investigate the effect of Gracilaria fisheri oligosaccharides (GFO) on inflammation and colonic epithelial barrier dysfunction in colitis mice. Methods: The animals were treated by oral gavage with distilled water, 1 000 mg/kg inulin, 100, 500, or 1 000 mg/kg GFO for 14 d, or treated with 50 mg/kg mesalamine for 5 d after colitis induction (on day 10). Histopathology, inflammatory cytokines, colonic permeability, and tight junction proteins were investigated by hematoxylin and eosin staining, immunohistochemical staining, Ussing chamber technique, and Western blotting assays, respectively. Results: GFO ameliorated histological damage in colitis mice when compared to untreated colitis mice. Treatments with 100, 500, and 1 000 mg/kg GFO reduced TNF-α expression, while IL-1β was significantly reduced in colitis mice treated with 500 and 1 000 mg/kg. Compared to untreated colitis mice, GFO increased transepithelial electrical resistance, reduced fluorescein isothiocyanate-dextran paracellular flux, and modulated tight junction proteins (occludin and claudin 2) in colitis mice. Conclusions: GFO has anti-inflammatory activity and could modulate colonic epithelial barrier dysfunction in acetic acid-induced colitis mice. Furthermore, GFO could modulate the expression of tight junction proteins that play important roles in colonic barrier function.

Independent and synergistic activity of the flavonoids of Gracilaria corticata as promising antidiabetic agents

The therapeutic approaches for Type 2 Diabetes Mellitus rely most on the usage of oral hypoglycaemic drugs. These drugs have adverse side effects and hence alternative medicines are continuously explored. The present study intends to investigate the antidiabetic potential of the flavonoids present in Gracilaria corticata. The flavonoids were isolated (FEGC) and their inhibitory activity on the carbohydrate hydrolysing enzymes such as α-amylase and α-glucosidase was analysed. The flavonoids were found to inhibit α-amylase and α-glucosidase with an IC50 value of 302 µg and 75 µg respectively. The synergistic effect of FEGC and luteolin was also investigated and the results show that both FEGC and luteolin inhibited synergistically at half their IC50 values. The observations of this study reveal that the flavonoids of G. corticata have potential antidiabetic activity and can act independently or synergistically in the management of Type 2 Diabetes Mellitus

A Structure Based Drug Designing Of Bioactive Compounds Of Gracilaria Edulis Against Virulent Bacterial Enzyme Aureolysin

The bioactive compounds of Gracilaria edulis were determined by using Gas Chromatography Mass spectroscopy. The drug compounds were screened for analyzing the inhibition potential against the virulent bacterial enzyme. In this research, the protein responsible for bacterial infection was docked against the drug compounds of Gracilaria edulis. The data of the virulent enzymes are studied and retrieved from PDB. The bioactive compounds were screened by Lipinski rule of five and ADMET properties. Using Autodock 4.2.6 the molecular docking analysis were done against virulent enzymes and was visualized by discovery studio 3.1. The bioactive compound eugenol with binding energy -4.42 Kcal/mol followed by 2 Heptene, 2,4,4,6 tetramethyl -3.89 Kcal/mol and 1, 2-Propanediol 2.77 Kcal/mol. The hydrogen and vanderwaals interaction of amino acids were studied. This research work mainly focuses on targeting the virulent enzymes that can reduce clinical costs by designing novel drug.

Carbohydrates and polyphenolics of extracts from genetically altered plant acts as catalysts for in vitro synthesis of silver nanoparticle

Eco-friendly biosynthetic approach for silver nanoparticles production using plant extracts is an exciting advancement inbio-nanotechnology and has been successfully attempted in nearly 41 plant species. However, an established model plantsystem for systematically unraveling the biochemical components required for silver nanoparticles production is lacking.Here we used Arabidopsis thaliana as the model plant for silver nanoparticles biosynthesis in vitro. Employing biochemical, spectroscopic methods, selected mutants and over-expressor plants of Arabidopsis involved in pleotropicfunctions and sugar homeostasis, we show that carbohydrates, polyphenolics and glyco-proteins are essential componentswhich stimulated silver nanoparticles synthesis. Using molecular genetics as a tool, our data enforces the requirement ofsugar conjugated proteins as essentials for AgNPs synthesis over protein alone. Additionally, a comparative analysis ofAgNPs synthesis using the aqueous extracts of some of the plant species found in a brackish water ecosystem (Gracilaria,Potamogeton, Enteromorpha and Scendesmus) were explored. Plant extract of Potamogeton showed the highest potentialof nanoparticles production comparable to that of Arabidopsis among the species tested. Silver nanoparticles production inthe model plant Arabidopsis not only opens up a possibility of using molecular genetics tool to understand the biochemicalpathways and components in detail for its synthesis.

Antioxidant activity of ethyl acetate and methanolic extracts of two marine algae, Nannochloropsis oculata and Gracilaria gracilis - an in vitro assay

ABSTRACT The aim of this study was to evaluate the antioxidant activity of ethyl acetate and methanolic extracts of two marine algae, Nannochloropsis oculata and Gracilaria gracilis. The extracts were assayed for total phenol and flavonoid content, DPPH free radical scavenging capacity, nitric oxide activity, iron chelation activity, and reducing power activity. Total phenol and flavonoid content were found to be high in both algae. Ethyl acetate extracts of both algae were found to exhibit significant antioxidant activity. Ethyl acetate extract of N. oculata exhibited a good capacity for iron chelation, nitrate oxide, and scavenging DPPH free radicals (72.95±2.30, 73.73±1.76, and 39.03±0.97% inhibition at 400 µg mL-1 respectively).

Relógio circadiano em eucariotos fotossintetizantes (Archaeplastida) e adaptação ao estresse / Circadian clock in photosynthetic eukaryotes (Archaeplastida) and stress adaptation

Relógios endógenos controlam grande parte de processos biológicos através de osciladores bioquímicos que coordenam a sinalização de pistas ambientais até vias metabólicas, permitindo a percepção do tempo e adaptação a mudanças rítmicas. Comportamentos cíclicos diários foram primordialmente descritos em plantas e, mais recentemente, têm fornecido informações valiosas sobre os ciclos de retroalimentação da transcrição e tradução de genes que controlam estes osciladores. O florescimento é um exemplo bem conhecido da importância da percepção do comprimento do dia através do relógio, processo intimamente regulado por fotorreceptores e pelos genes centrais e periféricos do relógio biológico. Em organismos multicelulares há uma combinação específica de genes mais expressa em cada tecido, podendo ter funções, fases e períodos diferentes, o que aumenta a complexidade desse mecanismo. Devido a isso, tem-se buscado modelos alternativos mais simples dentro dos eucariotos fotossintetizantes relacionados às plantas terrestres. Modelos simplificados facilitam, por exemplo, a avaliação da combinação de fatores que induzem o estresse e como o relógio biológico se altera, permitindo a antecipação de mudanças ambientais e sincronização da fisiologia com o meio ambiente. Neste trabalho, verificou-se como o relógio circadiano se ajusta ao estresse em 3 diferentes modelos: Gracilaria tenuistipitata (Rhodophyta), Ostreococcus tauri (Chlorophyta) e Saccharum sp (Embryophyta). Para isso, estabeleceu-se em G. tenuistipitata métodos para avaliação de crescimento e da fluorescência da clorofila de modo automático, comprovando da existência de ritmos circadianos. Além disso, após padronização de genes de referência para normalização das RT-qPCRs, o gene TRX ficou superexpresso durante a primeira hora após o déficit hídrico. Já em O. tauri, onde os genes centrais do relógio são conhecidos, mudanças na expressão de LOV-HK e TOC1 estão relacionadas com maior crescimento em baixa e alta temperatura, respectivamente. Uma combinação específica de luz, temperatura e salinidade pode ser um importante indutor de eflorescências que reflete mudanças transcricionais no oscilador central, o que pode ser comparado às florescências de plantas terrestres. Já em Saccharum sp tolerante à seca, ritmos de fotossíntese e de expressão de CCA1 sofrem mudanças de fase em suas oscilações e transcritos de HVA-22 e DRP são significativamente mais expressos sob dessecação. Em suma, o estresse em Saccharum sp reseta o relógio, aumentando o período de oscilação da fotossíntese. Em O. tauri induz maior crescimento, mantendo as características do relógio. Não foi possível avaliar o efeito do estresse no relógio de G. tenuistipitata, mas ferramentas foram desenvolvidas visando este objetivo. Estudos de respostas do relógio podem fornecer informações valiosas para o entendimento da reprodução e crescimento de organismos com elevado potencial de aplicações biotecnológicas

Endogenous clocks control a large range of biological processes through biochemical oscillators that coordinate the signaling of environmental cues to metabolic pathways, allowing the perception of time and adjust to rhythmic changes. Cyclical daily behaviors were first noticed in plants and, more recently, revealed information about the transcriptional-translational feedback loops of genes that control these oscillators. Flowering is a well-known process where the perception of day length by the clock is intimately regulated by photoreceptors and by the central and peripheric genes of the biological clock. Multicellular organisms have a tissue-specific combination of expressed clock genes that may have different phase and period, increasing the complexity of this mechanism. Due to this reason, alternative models have been proposed for land plants-related photosynthetic eukaryotes. New models can simplify, for example, which combination of factors induce stress and how the biological clock is altered, allowing the anticipation of environmental changes and synchronization of physiology and environmental factors. This work aimed to verify how the biological clock adjusts to different kinds of stresses in 3 species: Gracilaria tenuistipitata (Rhodophyta), Ostreococcus tauri (Chlorophyta) and Saccharum sp (Embryophyta). Automated measurement techniques for growth rate and photosynthesis were stablished for the red alga. This alga also showed, after establishment of reference genes for RT-qPCRs normalization, an overexpression of TRX during the first hour under water deficit. In O. tauri, where the central clock genes are known, changes in LOV-HK and TOC1 gene expression are related to a higher growth rate under low and high temperatures, respectively. Besides, a specific combination of light, temperature and salinity can be an important trigger of seasonal blooms that causes important transcriptional changes at the central oscillator, what is similar to land plants. In Saccharum sp tolerant to drought, photosynthesis rhythms and CCA1 expression change their phase under simulated water deficit and drought responsive transcripts like HVA-22 and DRP are significantly up-regulated. In short, stress resets the clock in Saccharum sp, increasing the period of photosynthesis oscillation. In O.tauri, it induces a higher growth, keeping clock features. It was not possible to verify clock responses to stress in G.tenuistipitata, but methods to do so were stablished. The biological clock responses to stress can provide invaluable information for the better understanding about the growth and reproduction of organisms with a high biotechnological potential

Comparative assessment of bacterial diversity associated with co-occurring eukaryotic hosts of Palk Bay origin.

Epibacterial communities of co-occurring eukaryotic hosts of Palk Bay origin (five seaweed species (Gracilaria sp, Padina sp, Enteromorpha sp, Sargassum sp, and Turbinaria sp) and one seagrass [Cymodaceae sp]) were analyzed for diversity and compared using 16S rRNA based Denaturant Gradient Gel Electrophoresis analysis. Diversity index revealed that Turbinaria sp hosts highest bacterial diversity while it was least in Gracilaria sp. The DGGE band profile showed that the epibacterial community differed considerably among the studied species. Statistical assessment using cluster analysis and Non-metric multidimensional scale analysis also authenticated the observed variability. Despite huge overlap, the composition of bacterial community structure differed significantly among the three closely related species namely Sargassum, Turbinaria and Padina. In addition, Enteromorpha and Sargassum, one being chlorophyta and the other phaeophyta showed about 80% similarity in bacterial composition. This differs from the general notion that epibacterial community composition will vary widely depending on the host phyla. The results extended the phenomenon of host specific epibacterial community irrespective of phylogeny and similarity in geographical location.

Searching for the best agarose candidate from genus Gracilaria, Eucheuma, Gelidium and local brands

Objective: To explore the potential of local agar of genus Gracilaria, Eucheuma, Gelidium and local brands as an alternative for imported agarose for DNA electrophoresis, and to examine their ability related to separation and migration of DNA fragments in DNA electrophoresis. Methods: Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment. Results: The local agar genus Gracilaria gigas, Gelidium, brand "B" and brand "S" could separate DNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose. Conclusions: Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by pH and sulfur control.

Searching for the best agarose candidate from genusGracilaria,Eucheuma,Gelidium and local brands

Objective:To explore the potential of local agar of genusGracilaria,Eucheuma,Gelidium and local brandsas an alternative for imported agarose forDNA electrophoresis, and to examine their ability related to separation and migration ofDNA fragments inDNA electrophoresis. Methods:Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment. Results: The local agar genusGracilaria gigas,Gelidium, brand B and brand S could separateDNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose. Conclusions:Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by pH and sulfur control.

Antiulcer, wound healing and hepatoprotective activities of the seaweeds Gracilaria crassa, Turbinaria ornata and Laurencia papillosa from the southeast coast of India

Seaweeds have bioactive compounds of interest in the pharmaceutical industry. In India, seaweeds are used exclusively for phycocolloids production and have not yet received consideration as a dietary supplement. So, it has become imperative to explore the biomedical potential of seaweeds and promote their utilization as a functional food. The seaweeds Turbinaria ornata, Gracillaria crassa and Laurencia papillosa, collected from the Tuticorin coast of the Southeast coast of India and selected based on preliminary screening, were extracted with acetone and evaluated for antiulcer, wound healing and hepatoprotective activities. L. papillosa showed the highest level of gastric protection activity (81%) at 200 mg/kg, comparable to the standard drug ranitidine (90%). G. crassa followed with 76%. G. crassa and L. papillosa, showed marked wound-healing activity. G. crassa at 200 mg/kg, showed a marked effect on the serum marker enzymes indicating prominent hepatoprotective activity. The noteworthy wound-healing and hepato-protective properties of G. crassa besides anti-ulcer activity next to L. papillosa were indicative of its potential for further consideration.

Algas marinhas possuem compostos bioativos de interesse para a indústria farmacêutica. Na Índia, as algas marinhas são usadas exclusivamente para a produção de ficocolóides e ainda não receberam a consideração como um suplemento dietético. Assim, tornou-se imperativo explorar o potencial biomédico de algas e promover a sua utilização como alimento funcional. As algas marinhas Turbinaria ornata, Gracillaria crassa e Laurencia papillosa, coletadas de Tuticorin, na costa sudeste da Índia, e selecionadas com base em triagem preliminar, foram extraídas com acetona e avaliadas quanto à atividade antiúlcera, de cicatrização de feridas e de hepatoproteção. L. papillosa mostrou o mais alto nível da atividade de proteção gástrica (81%) na dose de 200 mg/kg, comparável ao fármaco padrão, ranitidina (90%). G. crassa mostrou atividade de 76%. G. crassa e L. papillosa mostrou atividade martcante na cicatrização de feridas. G. Crassa, a 200 mg/kg, mostrou efeito alto sobre o marcador sérico das enzimas, indicando atividade hepatoprotetora proeminente. A notável cura de feridas e as propriedades hepatoprotetoras de G. Crassa, além da atividade antiúlcera, próxima da L. Papillosa, foram indicativos do seu potencial para uma análise mais aprofundada.

Biochemical and Nanotechnological Studies in Selected Seaweeds of Chennai Coast.

Three different seaweeds Gracilaria corticata J.Agardh ,Grateloupia lithophila Boergesen and Chaetomorpha antennina(Bory) kuetz used for the study were subjected for the estimation of carbohydrates, proteins, aminoacids, lipids and pigments such as chlorophyll a, chlorophyll b, carotenoid and phycobilins. They were also used for the nanoparticles synthesis and also checked for the blood glucose level changes by the oral administration of the seaweeds (0.5 g/day) to 6 mice for 20 days and with 3 mice as controls. The chaetomorpha, grateloupia and gracilaria estimation results showed 18.4%, 5.5%, 3.6% for carbohydrates, 15.8%, 30.5%, 23.7% for proteins, 4.9%, 22.94%, 11.04% for amino acids, 0.3%, 1.8%, 1.2% for lipids, 33.93, 1.35, 2.97 (mg/g fresh sample) for total chlorophyll, 0.2, 0.6, 5.49 (mg/g fresh sample) for carotenoid, 1.75, 2.1, 5.04 (μg/g fresh sample) for phycoerythrin respectively. They were also investigated for the extracellular biosynthesis of silver and gold nanoparticle and have achieved rapid formation of gold nanoparticles using Chaetomorpha antennina and Gracilaria corticata. It has been confirmed with the surface plasmon resonance.

Studies on radionuclides 228Ra, 238U, 228Th and 40 K in selected seaweeds of coastal Tamil Nadu, India.

Studies on natural and anthropogenic radioactivity assume greater importance in the context of human health and development. Hence two species of seaweeds viz: Gracilaria edulis and Ulva lactuca, from three high background radiation areas (Arockiapuram, Kadiapattinam and Kurumpanai) on the southwest coast of Tamil Nadu, and Mandapam as low background radiation area of the southeast coast of Tamil Nadu were studied for variations in activity concentration of 228 Ra, 40 K, 238 U and 228 Th. Among these radionuclides, 40K recorded significant inter-species variation while 238 U and 228 Th showed significant association. The overall mean concentration of radionuclides was found high in G.edulis (5.31, 57.49, 36.05, 356.55 Bq kg-1 for 228 Ra, 40K, 238U, 228 Th respectively), while the mean concentrations for U.lactuca were 4.88, 42.35, 34.40, 347.70 Bqkg-1 for 228 Ra, 40K, 238U, 228 Th respectively. The mean concentration of radionuclides was uniformly found low during northeast monsoon season in both the seaweed species.

Effect of depth on growth and pigment contents of the macroalgae Gracilaria bursa-pastoris

The effects of environmental parameters on biomass, growth and pigment content of the red seaweed Gracilaria bursa-pastoris (S.G. Gmel.) P.C. Silva was investigated under field conditions in Thau Lagoon (France). The seaweed was cultivated in cages placed at three depths (1.0, 2.0 and 4.0 m) over a one-year period. The results showed elevated biomass and growth values in the spring and autumn, when temperature, light and photoperiod values were similar. The highest specific growth rates (SGR) were obtained at 1.0 m (4.95±0.29% day-1) and 2.0 m (4.45±0.33% day-1). At a depth of 4.0 m, the seaweed never exceeded 2% day-1 and obtained null values in the summer. The concentrations of phycoerythrin (RPE) and chlorophyll (CHL a) showed maximum values in the winter and minimum values in the summer. This evolution was related to water temperature, light intensity and nitrogen content in the algal tissue. The results obtained in this study show that the water depth influenced the growth and pigment composition of G. bursa-pastoris.

Antioxidant activity and chemical composition of the non polar fraction of Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira)

Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira) (Gracilariales, Rhodophyta) are seaweeds that occur on the Brazilian coast. Based on their economic and pharmaceutical importance, we investigated the antioxidant activity of the methanolic, ethyl acetate and hexane extracts of both species. The hexane extracts display a high antioxidant activity and comparative analyses indicated G. birdiae as the most active species. Chemical investigation of these fractions showed several carotenoids and fatty acids, as well as cholesterol and sitosterol derivatives. HPLC-DAD analysis of G. birdiae showed violaxanthin (0.04 μg.mg-1 of dry material), antheraxanthin (5.31 μg.mg-1), aloxanthin (0.09 μg.mg-1), zeaxanthin (0.45 μg.mg-1) and β-carotene (0.37 μg.mg-1) as the major carotenoids. G. domingensis showed a similar carotenoid profile, however, with much lower concentration than G. birdiae. Gas chromatography coupled to mass spectrometry was used to determine other nonpolar compounds of these seaweeds. The main compounds detected in both studied species were the fatty acids 16:0; 18:1 Δ9; 20:3 Δ6,9,12, 20:4 Δ5,8,11,14. We found no specificity of compounds in either species. However, G. birdiae, presented higher contents of carotenoids and arachidonic acid than G. domingensis.

Use of geographic information systems (GIS) to identify adequate sites for cultivation of the seaweed Gracilaria birdiae in Rio Grande do Norte, Northeastern Brazil

This study was designed to select potential areas for cultivation of the seaweed Gracilaria birdiae Plastino & E.C. Oliveira (Gracilariales, Rhodophyta) on the coast of Rio Grande do Norte state, Brazil. The Geographic Information System (GIS) and multi-criteria evaluation (MCE) were used to identify the most suitable areas. The Analytical Hierarchical Process (AHP) was applied to establish MCE weights, thereby generating viable areas for species cultivation. From a total of 3316.82 ha, around 53.67% (1780.06 ha) were indicated as highly suitable areas, 40.93% (1357.58 ha) as moderately suitable and 5.40% (179.18 ha) as scarcely suitable for seaweed cultivation. Seven areas (1084.62 ha) are located on the northern coast and 20 (2232.20 ha) on the eastern coast. The results show that GIS can be used as an effective instrument for selecting seaweed cultivation areas.

Seasonal changes in the pigment composition of natural population of Gracilaria domingensis (Gracilariales, Rhodophyta)

The concentrations of phycobiliproteins (phycoerythrin and phycocyanin), chlorophyll-a and total soluble proteins were determined monthly in three strains (red, green and brown) of Gracilaria domingensis (Kützing) Sonder ex Dickie, collected from natural populations on the coast of Rio Grande do Norte, Brazil. In all the strains, pigment and protein concentrations were higher in the months of less sunlight and greater nitrogen availability and decreased gradually with increased sunlight and decreased nutrient concentration. The red strain showed higher concentrations of phycoerythrin and total soluble proteins. The difference in the concentration of biochemical components over the course of the year indicates species acclimation to different environmental conditions.

Preliminary Phytochemical, UV-VIS, HPLC and Anti-bacterial Studies on Gracilaria corticata J. Ag

Objective: The present study aimed to investigate the preliminary phytochemical analysis and UV-VIS, HPTC profiling and the antibacterial activity of Gracilaria corticata J. Ag extracts against the Gram positive and Gram negative bacteria. Methods: Preliminary phytochemical screening was carried out by Harborne method. The G. corticata extracts were tested against bacteria by the agar disc diffusion method. Results: The results of the presence study showed the presence of alkaloids, steroids, phenolic groups, saponins, tannin, flavonoids, terpenoids, glycosides and sugars. Proteins, xantoproteins, coumarins and catechin did not show any positive result for their presence in any of the six extracts of Gracilaria corticata tested. The result of the present study revealed the various behavior character of Gracilaria corticata crude drug. The UV-VIS spectrum profile of Gracilaria corticata methanolic, petroleum ether, benzene and aqueous extracts profiles were recorded. The HPLC profile of Gracilaria corticata petroleum ether benzene and aqueous extracts were tabulated. The maximum (9/12 bacterial pathogens) degree of antibacterial activity was observed in isopropanol soxhlet extracts followed by isopropanol cold extracts (7/12 bacterial pathogens). Conclusion: The results of the present study showed that G. corticata may be rich sources of phytoconstituents which can be isolated and further screened for different kinds of biological activities, depending on their reported therapeutic uses.

Analyses of photoprotective compounds in red algae from the Brazilian coast

Qualitative and quantitative studies of mycosporine-like amino acids (MAAs) in three species of the genus Gracilaria Greville (G. birdiae, G. domingensis and G. tenuistipitata) were performed. A simple and efficient extraction procedure based on ethanol was described. HPLC, UV and mass spectrometry experiments revealed different profiles between extracts obtained from one species cultivated in the laboratory (G. tenuistipitata) and two species collected in their natural environment (G. birdiae and G. domingensis). The levels detected in the latter two species were approximately 150 times higher than in the species cultivated in vitro. This study revealed that G. birdiae and G. domingensis present a potential source for economical exploration of MAAs.

Absorption of metals and characterization of chemical elements present in three species of Gracilaria (Gracilariaceae) Greville: a genus of economical importance

Gracilaria Greville is a genus of seaweed that is economically explored by the cosmetic, pharmaceutical and food industries. One of the biggest problems associated with growing Gracilaria is the discharge of heavy metals into the marine environment. The absorption of heavy metals was investigated with the macroalga Gracilaria tenuistipitata Zhang et Xia, cultivated in a medium containing copper (Cu) and cadmium (Cd). In biological samples, EC50 concentrations of 1 ppm for cadmium and 0.95 ppm for copper were used. These concentrations were based on seaweed growth curves obtained over a period of six days in previous studies. ICP-AES was used to determine the amount of metal that seaweeds absorbed during this period. G. tenuistipitata was able to bioaccumulate both metals, about 17 percent of copper and 9 percent of cadmium. Basal natural levels of Cu were found in control seaweeds and in G. tenuistipitata exposed to Cd. In addition, the repertoire of other important chemical elements, as well as their concentrations, was determined for G. tenuistipitata and two other important seaweeds, G. birdiae Plastino & Oliveira and G. domingensis (Kützing) Sonder ex Dickie, collected in natural environments on the Brazilian shore.