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Made available in DSpace on 2022-04-29T08:46:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Gracilariales is a clade of florideophycean red macroalgae known for being the main source of agar. We present a de novo genome assembly and annotation of Gracilaria domingensis, an agarophyte alga with flattened thallus widely distributed along Central and South American Atlantic intertidal zones. In addition to structural analysis, an organizational comparison was done with other Rhodophyta genomes. The nuclear genome has 78 Mbp, with 11,437 predicted coding genes, 4,075 of which did not have hits in sequence databases. We also predicted 1,567 noncoding RNAs, distributed in 14 classes. The plastid and mitochondrion genome structures were also obtained. Genes related to agar synthesis were identified. Genes for type II galactose sulfurylases could not be found. Genes related to ascorbate synthesis were found. These results suggest an intricate connection of cell wall polysaccharide synthesis and the redox systems through the use of L-galactose in Rhodophyta. The genome of G. domingensis should be valuable to phycological and aquacultural research, as it is the first tropical and Western Atlantic red macroalgal genome to be sequenced. Laboratory of Algal Biochemistry and Molecular Biology Department of Biochemistry Institute of Chemistry University of São Paulo, Av. Prof. Lineu, Prestes, 748, SP CNRS UMR 7232 Biologie Intégrative des Organismes Marins (BIOM) Sorbonne Université, Observatoire Océanologique - F-66650 Department of Botany Institute of Biosciences University of São Paulo, R Matão 277, SP Departamento de Bioquímica y Biología Molecular Facultad de Ciencias Químicas y Farmacéuticas Universidad de Chile Universidad de Chile - Independencia Department of Oceanography and Limnology Federal University of Rio Grande do Norte - Via Costeira, Praia de Mãe Luiza, s/n, RN Phycology Research Center Institute of Botany Secretary of Infrastructure and Environment of São Paulo State, Brazil - Av. Miguel Estefano, 3687, Água Funda, SP School of Pharmaceutical Sciences São Paulo State University (UNESP), Rod. Araraquara-Jaú km 1, Campus Ville, SP Station Biologique de Roscoff UMR 8227 Integrative Biology of Marine Models - CS 90074 Department of Biochemistry Institute of Chemistry University of São Paulo, Av. Prof. Lineu Prestes, 748, SP School of Pharmaceutical Sciences São Paulo State University (UNESP), Rod. Araraquara-Jaú km 1, Campus Ville, SP

Laurencia catarinensis (Ceramiales, Rhodomelaceae) has a high diversity of secondary metabolites such as acetogenin and halogenated terpenoids, with biological activities. We tested different combinations of auxins and cytokinins to evaluate their effects on the growth, total soluble proteins, pigments, and carbohydrates of L. catarinensis with the aim of improving the culture techniques of this species. To accomplish this, algae were cultivated in seawater enriched with quarter strength of von Stosch solution (VSES/4) with the addition of plant growth regulators (PGRs), and the treatment control without PGRs addition. The auxins tested were indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), and cytokinins were benzylaminopurine (BA) and 2-isopentenyladenine (2iP), in the following combinations: IAA:BA, IAA:2iP, 2,4-D:BA, and 2,4-D:2iP, in the concentrations of 5:5, 5:50, 50:5, and 50:50 μM for each auxin:cytokinin combination. Addition of PGRs had significant effects on the growth rates of L. catarinensis, which varied from 7.62 ± 0.12% to 9.30 ± 0.55% day−1. The highest growth rates were observed in treatments with 5:5 μM of IAA:BA and 2,4-D:BA, and 50:5 μM of 2,4-D:2iP. Higher contents of total soluble proteins were observed in treatments with 50:50 μM of IAA:BA and 2,4-D:BA. The auxin:cytokinin combinations inhibited allophycocyanin contents, but did not affect chlorophyll a and carbohydrate concentrations. Therefore, supplementation of auxins and cytokinins, especially the IAA:BA and 2,4-D:BA combinations, is useful approach to stimulate growth rates or soluble protein contents of L. catarinensis, improving the cultivation of this species with high biotechnological potential.

The genus Hypnea (Rhodophyta, Gigartinales) has currently 61 accepted species distributed in tropical, subtropical, and temperate regions, growing in different habitats with a wide range of environmental factors and interactions with abiotic and biotic factors. Some Hypnea species are consumed by humans mostly in Asian and Indo-Pacific countries and are also exploited as raw material for kappa-carrageenan production, consequently, have been harvested and/or cultivated in several countries for decades. Hypnea musciformis has the widest geographical distribution around the world and it is the most studied species. However, more molecular studies on H. musciformis from different countries are necessary to understand the phenotypic plasticity and to reveal cryptic species. The present review is a compilation of information on taxonomy, morphology, anatomy, life history, distribution, ecology, physiology, cultivation and harvesting, chemical composition, and biotechnological applications. Although Hypnea species are well known as sources of carrageenans, reports on chemical diversity and biological activities highlight their remarkable potential for biotechnological applications.

A small red alga was isolated into culture from rhodoliths collected on the Piaui coast, northeastern Brazil. Molecular data from the plastid-encoded rbcL gene, combined with morphological and ultr...

Made available in DSpace on 2019-10-06T16:40:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Benthic marine algae, especially Rhodophyta, are within a well-known marine group able to produce secondary metabolites with bioactive properties. Among them are halogenated terpenes, synthesized by vanadium-dependent haloperoxidase (V-BPO). The red alga Ochtodes secundiramea (Montagne) M. Howe produces high amounts of halogenated monoterpenes (HMT) which have the potential to control phytopathogenic fungi. Culture closed a system is a tool used to manipulate conditions to increase the synthesis of HMT and other metabolites. The apical segments of O. secundiramea were cultivated in a bioreactor, either in seawater enriched with half strength von Stosch’s solution (VSES/2) without (control) and with the addition of 250 mg L−1 bromine (treatment). In response to these conditions, specific growth rate, HMT profile, soluble protein, phycobiliproteins, soluble carbohydrate, and chlorophyll as well as the V-BPO activity, uptake, and accumulated bromine within the biomass were evaluated. The treatment did not promote significant alterations in the growth but increased the V-BPO activity and bromine uptake and incorporation (2.5 fold). No changes in the HMT profiles of the extracts from both cultures conditions were observed by gas chromatography–mass spectrometry analyses, whereas the values of total soluble protein and phycobiliproteins were 2-fold higher in samples from the bromine-enriched medium when compared to samples from control. These results support the evidences of protective effects promoted by V-BPO activity. Furthermore, carbohydrate and chlorophyll contents were not affected by experimental conditions. These results provided new low-cost strategies that can be applied to increase of certain biomass components, which here are algal proteins, especially in Rhodophyta-based biotechnological industries for food and agriculture. Coordenadoria de Engenharia de Pesca Universidade Estadual Paulista—UNESP, Campus Experimental de Registro, Vila Tupi: Av. Nelson Brihi Badur, 430 Departamento de Bioquímica Instituto de Química da Universidade de São Paulo, Av. Prof. Lineu Prestes, 748—Cidade Universitária Núcleo de Pesquisa em Ficologia Instituto de Botânica da Secretaria de Estado do Meio Ambiente, Av. Miguel Estefano, 3687, Água Funda Coordenadoria de Engenharia de Pesca Universidade Estadual Paulista—UNESP, Campus Experimental de Registro, Vila Tupi: Av. Nelson Brihi Badur, 430

Background/Aim: Antarctic seaweeds are considered a promising source of compounds with anticancer activity. Colorectal cancer (CRC) is one of the most incident cancers with high mortality rates worldwide. This work aimed to characterize chemically extracts of the Antarctic macroalgae Iridaea cordata, Cystosphaera jacquinotii and Desmarestia anceps and to evaluate the cytotoxic effects against human colon cancer HCT 116 cell line. Materials and Methods: The extracts were obtained by depletion using an ultrasound probe and were identified by High-Performance Liquid Chromatography (HPLC) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). Cell viability was determined by MTT assay. Results: Hexanic and chloroform extracts of the I. cordata and the hexanic, chloroform and methanolic extracts of D. anceps were able to inhibit growth of colorectal cancer cells in the three different incubation times (24, 48 and 72 h). Through GC analysis, 01 compounds were identified in the hexane extract and 02 compounds in the chloroform extract of the algae I. cordata. The hexane extract of D. anceps macroalgae presented 5 compounds, chloroform extract 10 and methanolic extract 3 respectively, with special highlight to fucosterol. Carotenoid analysis by HPLC identified β-carotene in all species, while zeaxanthin was present in the spectrum of I. cordata and C. jacquinotii. Fucoxanthin and violaxanthin were confirmed in the brown seaweeds C. jacquinotii and D. anceps. Conclusion: Extracts of macroalgae I. Cordata and D. anceps may be a source of therapeutic agents against CRC.

Increased greenhouse gas concentrations in the Earth's atmosphere have resulted in global change, such as ocean warming and sea level rise. Increased salinity in estuaries is expected as a result of sea level rise and warming. Thus, we analysed the interactive effects of increased temperature and salinity on multiple physiological responses of Bostrychia montagnei and B. calliptera from two biogeographic provinces, Tropical Southwestern Atlantic (TSA) and Warm Temperate Southwestern Atlantic (WTSA). Macroalgae were cultured under three salinities (15, 25 and 35 PSU) and three temperatures: mean sea surface temperature (SST: 27 °C for TSA and 24 °C for WTSA), an RCP8.5 ocean warming scenario (SST + 5 °C), and a maximum temperature to test the algal upper thermal tolerance limits (RCP8.5 + 2 °C). Macroalgae from both localities decreased their growth under increased temperature and salinity. RCP8.5 + 2 °C was lethal for both macroalgae from TSA. RCP8.5 and RCP8.5 + 2 °C at 35 PSU were lethal for B. calliptera from WTSA, due to the interactive effects between increased temperature and salinity. Overall, increased salinity decreased the effective quantum yield and relative electron transport rate in algal photosynthesis. Our results demonstrated that the macroalgae synthesized proteins, carbohydrates (polysaccharides and low molecular weight carbohydrates), and antioxidants to tolerate detrimental temperatures and salinities. Our results also demonstrated that the macroalgae adjusted their pigment contents (phycobiliproteins, total carotenoids, and chlorophyll a) for efficient light-harvesting under thermal and saline stress. Our findings suggest that ocean warming and increased salinity in estuaries will be detrimental to B. montagnei and B. calliptera populations from both biogeographic provinces, especially to those from TSA that already live closer to their upper thermal tolerance limits.

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Marine heatwaves (MHWs) frequency and intensity are increasing around the globe, affecting marine ecosystems' structure and functioning. Understanding how key marine species respond to these short-term extreme events is urgent for predicting damage to coastal ecosystems. Hypnea pseudomusciformis presents distribution in different floristic provinces on the Brazilian coast: tropical, transition and warm-temperate. Here, we evaluate the effects of simulated heatwaves on H. pseudomusciformis populations by measuring the changes in algal growth, pigment content, and photosynthesis. Based on data for the last four decades, we characterized the MHW patterns for each of the three collection sites. Perturbation levels were identified as average intensity heatwave (Δ +2 °C), maximum intensity heatwave (Δ +4 °C) and extreme intensity heatwave (Δ +6 °C), with an average duration of seven days. Based on growth rate data, corroborated with measurements of photosynthesis fluorescence and pigment contents. H. pseudomusciformis populations exhibit distinct tolerance and physiological responses to MHWs. The tropical and transition specimens were affected by Δ + 4 °C and Δ + 6 °C MHW scenarios, while the warm-temperate specimens was the only one to recover in all the MHW scenarios tested. These data are worrisome under a global warming scenario and an increase in MHWs, indicating that tropical and transition specimens of H. pseudomusciformis may be at risk of local extinction. This knowledge will be fundamental in driving any future management intervention or policy change for the conservation of marine ecosystems.

Antarctica is characterized by extremes of climate and biogeographic isolation from other continents by distance, high depths, and the Antarctic Circumpolar Current. Even under these harsh conditions, macroalgae thrive in different coastal ecosystems contributing to primary production and serving as habitat and food for a variety of species of marine fauna. However, it is known that the Antarctic marine flora presents low species richness compared to other biogeographical regions: until the past decade a number of 120 Antarctic seaweeds had been reported. On the other hand, long geographical isolation and extreme climatic and oceanographic conditions justify their high degree of endemism (ca. of 33–40%). A new compilation of the Antarctic seaweed diversity is presented in this chapter, reporting a list of 151 species cited to the entire Antarctica, comprising 85 Rhodophyta, 34 Ochrophyta (Phaeophyceae and Chrysophyceae), and 32 Chlorophyta with an endemism degree of 27%, lower than in previous reports. Molecular approaches based on different markers (ITS, UPA, COI-5P) are being used to assist species identification. The collection of marine specimens in Antarctica is expensive and still very difficult, and therefore, the occurrence for many species can become inaccurate. The difficult access to samples is another limitation, which could explain that most of the best known species are concentrated around scientific stations. Consequently, the macroalgal diversity in Antarctica and its distribution is probably underestimated. A better knowledge on this diversity and its distribution is urgent, as the region is facing significant climate changes that may drive shifts on the assemblages of macroalgae.

The seaweed biogeography and diversity in remote areas, such as Antarctica, should be reassessed considering the population shifts induced by global changes. This chapter addresses the hypothesis that ecological isolation can be disrupted and that biogeographical distribution of some species could be altered by thermohaline changes, which in turn would alter the dispersal patterns of macroalgae driven by severe meteorological and oceanographic events. Algal growth and distribution are limited by physical and biological processes, acting as sensitive bioindicators of changes or abrupt oscillations in the environmental regimes. In addition, Antarctica represents a natural laboratory highly susceptible to the climate changes, and the monitoring of their ecosystems may help to predict their potential effects beyond the Southern Ocean. Another fundamental issue is to understand the increase in species richness due to the cryptic and alien species, considering shifts in their biogeographic distribution. The large-scale patterns of some of these species reported for Antarctica may provide clues to reevaluate aspects of endemism, biological corridors, ecotone, and expansion of geographical distribution of algal assemblages facing climate changes, reinforcing the hypothesis that these isolated ecosystems will become gradually more connected.

Extracts of brown algae are used commercially for agricultural crops due to their plant growth-promoting effects and they can also be applied to help improve seaweed cultivation. Gracilaria caudata is commercially exploited as a raw material for agar production in Brazil, and Laurencia catarinensis is a source of halogenated terpenoids with several biological activities. Investigations to understand the development of seaweeds of biotechnological interest are required in order to improve their cultivation and the sustainability for biomass production on an industrial scale. The aim of the present study was to evaluate the effects of Ascophyllum/Acadian marine plant extract powder (AMPEP), a commercial, water-soluble extract of the brown alga Ascophyllum nodosum, on the growth, branching development, and pigment content of G. caudata and L. catarinensis. Four concentrations of AMPEP (0, 0.1, 1.0, and 5.0 mg L−1) were added to sterilized seawater (seawater+AMPEP), and to a medium comprised of half-strength von Stosch solution (VSES/2+AMPEP). Experiments were performed under conditions of 23 ± 2 °C, a light:dark cycle of 14:10 h, salinity at 32 psu, and photon flux densities of 60 ± 10 μmol photons m−2 s−1. Data were analyzed by one-way ANOVA, followed by a posteriori multiple comparison, Student-Newman-Keuls’ test. Treatments of seawater+AMPEP at concentrations of 0.1 and 1.0 mg L−1 stimulated the growth rates of G. caudata when compared to the control. However, the effects of seawater+AMPEP and VSES/2+AMPEP on the branching architecture of the thalli were not significant for either species. Concentrations of phycoerythrin, phycocyanin, allophycocyanin, and chlorophyll-a in L. catarinensis were stimulated by the highest concentration of VSES/2+AMPEP (i.e., 5.0 mg L−1). This is the first study to report the stimulatory effect of AMPEP on the phycobiliprotein contents of selected red algae. Furthermore, seawater+AMPEP in concentrations of 0.1 and 1.0 mg L−1 stimulated growth rates of G. caudata, which could be applied in its large-scale cultivation. The results obtained for G. caudata and L. catarinensis, an agar-producing and a terpenoid-producing species, respectively, contributed to extending the knowledge of the beneficial uses of a brown seaweed-derived extract with biostimulatory properties for use with cultivated, economically important red algae.

The use of algal biomass as bioproducts source has been studied; in fact, some species produce a high amount of carbohydrates, proteins, pigments and oils, and such species could be used for the production of several products, even nutraceuticals and biofuels. To evaluate this potential, the biochemical composition of macroalgae collected along the Brazilian coast, including 14 species of Rhodophyta, 4 of Chlorophyta, and 7 of Phaeophyceae, was investigated. Photosynthesis was estimated for species belonging to the most representative orders in order to evaluate its relationship to macromolecule biosynthesis. There was a wide variation in the content of lipids, carbohydrates and proteins, and the highest values were found in the species Dictyota menstrualis (Hoyt) Schnetter, Horning & Weber-Peukert, Gracilaria mammillaris (Montagne) M.A.Howe, and Aglaothamnion uruguayense (W.R. Taylor) Aponte, D.L. Ballantine & J.N.Norris, respectively. The content of phycobiliproteins was also higher in this last species. Results showed that D. menstrualis to be the best source for biodiesel production based on its high photosynthetic rate, high content of lipids and fatty acids, and high content of monounsaturated fatty acids. Spatoglossum schroederi (C.Agardh) Kutzing showed a high content of polyunsaturated fatty acids and ω-3, making it interesting for nutraceutical application. A distinct pattern among the different groups of macroalgae in relation to photosynthesis and biosynthesis of macromolecules was also observed, suggesting that different strategies should be undertaken to divert algae metabolism to the production of the metabolite of interest.

Gracilaria domingensis (Kutzing) Sonder ex Dickie is widely distributed in the Brazilian coast and is one of a few Gracilaria species with occurrence in the southern region of the country. Its commercial importance is in the use in human food (in natura) and knowledge of the physiology is fundamental to make its cultivation successful. The objectives of the present work were to determine the limits of tolerance to temperature and irradiance variations and to evaluate comparatively their effects on growth rates and contents of total soluble proteins and pigments in female gametophytes of G. domingensis from Brazilian tropical region (ES strain) and from subtropical region (SC strain). Variations in temperature (from 15 to 35 °C) and irradiance (from 20 to 250 μmol photons m−2 s−1) were tested. Both strains tolerated temperature variation from 15 to 30 °C, but died at 35 °C. The ES strain had higher growth rates (from 3.1 to 6.1% day−1) in relation to the SC strain (from 1.3 to 4.1% day−1), but the two strains had the highest growth rate at 25 °C. The ES strain had higher concentrations of total soluble proteins at low temperature (15 °C), while the SC strain showed higher protein concentrations at high temperatures (25 and 30 °C). In addition, the chlorophyll a concentration of the ES strain was higher at 20 °C and lower at 30 °C. The irradiance variation influenced the growth rates of the two strains (from 2.7 to 6.0% day−1) and the lowest growth rates were observed at irradiance of 20 μmol photons m−2 s−1 and the highest growth rates were observed at a wide range of irradiance variation (from 40 to 250, and from 60 to 250 μmol photons m−2 s−1 for SC and ES strains, respectively). The studied strains of G. domingensis showed higher concentrations of total soluble protein at low irradiances (20, 40, and 80 μmol photons m−2 s−1). The highest concentrations of phycoerythrin (423.0 μg g−1 FW) and phycocyanin (215.3 μg g−1 FW) were observed in the ES strain grown at low irradiance (40 μmol photons m−2 s−1). The chlorophyll a concentration of the two strains decreased with increased irradiance, indicating a photoacclimation. Our results showed that the tropical strain of G. domingensis has higher growth rates over a broader temperature range than the subtropical strain, which could be an advantageous feature for maricultural purposes.

The present study characterizes the spatial distribution of seaweed diversity on eight islands from the South Shetlands based on an updated taxonomic survey, discussing the higher number of species compared with previous studies and the possible relationships with environmental parameters. Seaweeds were sampled in Deception, Livingston, Halfmoon, Robert, Nelson, King George, Penguin, and Elephant Islands during the austral summer between 2010 and 2013 in intertidal and shallow subtidal zones. The taxonomic analyses evaluated morphological characteristics, reproductive structures, and molecular features. Physicochemical parameters of seawater were also monitored using standard analytical methods. A total of 104 species of benthic marine algae were identified (28 Phaeophyceae, 24 Chlorophyta, and 52 Rhodophyta), ~82% of all seaweeds taxa described to Antarctica, including six new records previously recorded only at lower latitudes, four confirmed taxa, and two putative new species. Spatial variation in species diversity was observed among the collecting sites, and Livingston and King George Islands showed the highest diversity among the islands. Deception, an area with geothermal activity and intense tourism, was dominated by opportunistic and broadly distributed filamentous green algae. Antarctic macroalgae diversity was higher than in previous studies, most likely due to more efficient techniques of sampling, and combined taxonomical methods. However, changes in the biogeographical distribution or introduction of some taxa, resulting from anthropogenic activities and/or climate changes, should be considered. Therefore, the higher number of taxa and the new records reported in this study suggest the need for long-term monitoring in the area for conservation purposes.

La Division Rhodophyta se caracteriza por tener representantes de macroalgas con valor comercial, debido a sus ficocoloides (carragenanos y agaranos). Ahnfeltia plicata, es una macroalga productora de agarosa y por lo tanto representa una oportunidad para la pesca artesanal y la industria. Praderas naturales de A. plicata observadas en Seno Skyring, Region de Magallanes, presentan variantes de color amarillas y rojas, que se adaptan ecofisiologicamente a las condiciones ambientales de sus habitats. Uno de los parametros fotosinteticos para evaluar el estado fisiologico de las macroalgas, es la concentracion de pigmentos fotosinteticos. El objetivo del presente estudio, fue determinar las concentraciones de clorofila α y ficobiliproteinas, de variantes amarillas y rojas de A. plicata, que habitan en el sector de Seno Skyring, Region de Magallanes. Se realizo la extraccion de pigmentos, mediante el uso de nitrogeno liquido y acetona al 90%. Las variantes rojas presentaron las mayores concentraciones de pigmentos fotosinteticos en base a AFC (287,443 ± 202,045 ug/g MF ± ES); FC (144,780 ± 89,430 ug/g MF ± ES); FE (367,850 ± 219,185 ug/g MF ± ES) y clorofila α (Chl a: 61,975 ± 219,185 ug/g MF ± ES). Estos resultados sugieren adaptabilidad a variaciones abioticas ambientales para la variante roja de A. plicata, derivado de una posible mayor capacidad de absorcion de la energia luminosa. Abstract The Rhodophyta Division is characterized by having representatives of macroalgae with commercial value due to their phycocolloids. Ahnfeltia plicata It is a macroalgae producing agarose and therefore an opportunity for artisanal fisheries and industry. Natural meadows of A. plicata from Skyring Sound (Magellan Region), display yellow and red variants that should adapt eco-physiologically to environmental conditions of their habitats. The concentration of photosynthetic pigments is one of the parameters used to assess the physiological state of the seaweeds. The objective of this study was to determine the concentrations of chlorophyll a and phycobiliproteins, in the yellow and red variants of A. plicata, inhabiting the Skyring Sound. The pigment extraction was performed using liquid nitrogen and acetone at 90%. The

Among the red algae, Kappaphycus and Eucheuma are the two most commercially important carrageenophytes farmed extensively in Southeast Asian countries; they rank top in production in terms of volume of raw material produced. The farming of carrageenophytes has emerged as a successful enterprise and provides a promising, alternative livelihood option for low-income, coastal communities in a number of countries. In 2014, carrageenophyte production worldwide, surpassed other red seaweeds and was placed at the top of the production rankings with 10.99 million MT wet weight (77% of total production of farmed red seaweed) and Indonesia being a major producer. However, over time, the productivity of the crop (carrageenophytes) has declined in some regions due to sourcing of seedlings from single, selected genetic stocks considered to have higher yield potential which resulted in strain fatigue, or loss of vigour. The incidences of disease and epiphytic infestations are on rise in recent times which have severely affected biomass production, as well as the yield and product quality (carrageenan). In order to circumvent the crop productivity issues arising from clonal propagation, the raising of planting materials from spores, derived through the red algal sexual reproductive cycle, has been initiated to support the sustainability of selected, farmed carrageenophytes. Alternatively, in vitro tissue culture techniques have also been explored to not only rejuvenate the vigour of seedlings (i.e. the out-planting material) but also to seek seedlings resilient to stress, disease and epiphytes to act as an invigorated mother stock. These efforts have succeeded to a great extent in the development of appropriate techniques for explant culture, callus induction, callus sub-culture and regeneration to micro-propagules with improved traits. The present chapter briefly summarizes the developments and success achieved in micro-propagation of Kappaphycus and Eucheuma and also provides pointers to both gaps and priority areas for future research required for the advancement of sustainable farming of these carrageenophytes.

Along with the search for new species of seaweeds with biofilter capacity, it is also necessary to understand the physiological and biochemical responses of these seaweeds cultivated in different availabilities of nitrate, ammonium, and phosphate. To accomplish this, a laboratory study was performed to evaluate the ability of Hypnea aspera Kutzing (Gigartinales, Rhodophyta), to growth under different nitrate, ammonium, and phosphate availabilities and to uptake, assimilate, and remove these nutrients from seawater. Treatments were composed of sterilized seawater enriched with quarter-strength von Stosch’s nutrient solution modified (without any nitrogen and phosphorus compounds). Nitrate or ammonium, together with phosphate, was added in combined N/P ratios of 100:1 and 10:1. Nitrate concentrations varied from 0 to 150 μM, and ammonium concentrations varied from 0 to 70 μM. Growth rates of H. aspera increased with nitrate addition, and the highest value was 4.68 ± 0.76 % day−1 in 150 μM, but the addition of high ammonium concentration (70 μM) in N/P ratio of 10:1 inhibited the growth rates (−3.89 ± 1.03 % day−1). Nitrogen was accumulated as proteins and phycobiliproteins, mainly phycoerythrin, at higher phosphate availability (N/P ratio of 10:1) for nitrate addition (150 μM for proteins and 50, 100, and 150 μM for phycoerythrin), and lower phosphate availability (N/P ratio of 100:1) for ammonium addition (50 and 70 μM for proteins and 50 μM for phycoerythrin). Nitrogen and phosphate were assimilated into thallus in all treatments with nutrient addition. Hypnea aspera showed high removal efficiency (higher than 90 %) of nitrate, nitrite, ammonium, and phosphate present in the seawater. These results suggest that H. aspera could be cultivated in integrated multitrophic aquaculture systems to reduce nutrient loading in eutrophic seawater.

The activities of bioactive compounds can be influenced by countless factors, including post-collection sample treatment. In this study, the activities of Ochtodes secundiramea extracts obtained using different processes are compared; the biomass was macerated immediately, lyophilized in liquid nitrogen, or dried in an oven at 50 °C after collection. The chemical profiles of the extracts were evaluated using gas chromatography-mass spectrometry (GC-MS), and their biological activities were assessed using qualitative and quantitative bioautography thin-layer chromatography (TLC) assays against phytopathogenic fungi. Preparative high-performance liquid chromatography (HPLC) was employed to isolate the major compound observed in semi-quantitative (CG-MS). The biomass processing methods were shown to influence the chemical profiles of the extracts that promote the oxidation of halogenated monoterpenes; however, C10H15Br2Cl was the major compound identified in all of the extracts regardless of the preparation method used. Similarly, changes in qualitative antifungal activity were observed depending on the preparation method, even though the minimum amount of material required for the inhibition of fungal growth (the activity detection limit) was 5 μg in all cases. The activity detection limits for the HPLC-purified majority compound were 5 and 10 μg against Cladosporium sphaerospermum and Colletotrichum lagenarium, respectively; these values are similar to those obtained for the crude extracts. These results point towards the possibility of using these crude extracts for the control of anthracnose in cucumbers post-harvest.

Bioinvasion events causing serious environmental damage have been a concern with the mariculture of Kappaphycus alvarezii (Doty) Doty ex P.C. Silva, suggesting the importance of studying the biological aspects of drifting specimens of K. alvarezii for monitoring programs. The present study aims to evaluate the tolerance and growth of drifting color variants of K. alvarezii under different temperatures and salinities to determine their physiological capacity for growing outside cultivation rafts. Drifting color variants were collected in Paraiba State, Brazil, in November 2011(dry month) and August 2012 (rainy month), and cultivated in the laboratory under different temperatures (20, 24, 28, and 32 °C) and salinities (15, 25, 35, 45, and 55 psu). Growth rates as well as pigment and protein contents were determined. Results showed that drifting specimens collected in the dry month showed higher tolerance to variation in temperature (20 to 28 °C) and salinity (25 to 35 psu) than drifting specimens collected in the rainy month. Higher growth rates occurred in samples cultured at 20 and 24 °C (2.8–3 % day−1) and 25 to 35 psu (3.4–3.5 % day−1), suggesting temperature and salinity optima. Higher phycobiliprotein levels were observed in the red and brown variants under hypersaline conditions (45 and 55 psu). Higher chlorophyll a contents were associated with samples cultivated at 20–24 °C and 24–35 psu. Based on the results of the present study, drifting specimens collected in dry month are more tolerant to temperature and salinity variations, suggesting that the drifting K. alvarezii should be monitored especially during this period to prevent its establishment outside the cultivation rafts and dispersion along the northeastern coast of Brazil.

The effects of plant growth regulators and irradiance on growth, callus formation and the process of direct and indirect regeneration were studied in axenic cultures of the green and red morphs of Gracilaria domingensis. Apical and intercalary segments from both color morphs were cultivated in ASP 12-NTA solid medium (0.5% agar) supplemented with auxins (indole-3-acetic acid, IAA; 2,4-dichlorophenoxyacetic acid, 2,4-D) and cytokinins (kinetin; 6-benzylaminopurine) in concentrations ranging from 0.5 to 50.0 μM and under 50 and 150 μmol photons m−2 s−1. In experiments to induce direct and indirect regeneration, explants and basal calluses isolated from apical and intercalary segments were cultivated in ASP 12-NTA liquid medium for 4 wk and then Von Stosch liquid medium for 3 wk under the same conditions as those noted for solid medium culture. The response to plant growth regulators and irradiance was dependent on the explant and color morph. In general, 2,4-D inhibited growth processes, while IAA and 6-ben...

Chondracanthus chamissoi (C. Agardh) Kutzing (Gigartinales, Rhodophyta) is an edible species and commercialised for carrageenan production in Chile. Investigations on growth and development are needed to improve its cultivation; therefore, this study aims to evaluate the effects of plant growth regulators (PGRs) on its growth and morphogenesis. PGRs tested were two auxins [indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D)] and one cytokinin (benzylaminopurine (BA)) in concentrations of 0.5, 5.0 and 50.0 μM. These PGRs were added to seawater enriched with half strength of von Stosch solution and were gelled with 0.6 % agar, and treatment control (without PGR addition) was conducted simultaneously. Apical and intercalary segments were used as initial explants. Each treatment was tested with six replicates of five axenic explants, and statistical analyses were performed. After culturing in a solid medium for 10 weeks to induce growth and callus formation, explants were cultured in liquid medium with the same experimental conditions for 10 weeks. Effects of auxins (IAA and 2,4-D) and the cytokinin BA on growth rates of apical segments of C. chamissoi were not significant, while low concentration of IAA stimulated the growth of intercalary segments. On the other hand, high concentrations of BA and IAA stimulated the callus formation in apical and intercalary segments, respectively. In liquid medium, PGR did not have a significant effect on growth rates of apical segments, while 2,4-D in concentrations from 0.5 to 50.0 μM stimulated growth of intercalary segments, and formation of lateral branches was stimulated by low 2,4-D in apical segments. These results suggest that PGRs have a regulatory role on callus formation and growth of specific explants of C. chamissoi. Furthermore, the formation of lateral branches stimulated by auxin could be used for seedling production under controlled conditions and could improve the micropropagation and cultivation of C. chamissoi in the Chilean coast.

A new species, Gayralia brasiliensis (Ulotrichales, Chlorophyta), is described from Brazil on the basis of ontogenetic, morphological, and molecular phylogenetic data. Liberation of zooids from the monostromatically bladed thalli occurred by disintegration of the zooidangium wall, releasing four biflagellate cells with prominent eyespots. Fusion of zooids was not observed. After zooid attachment, cell divisions gave rise to uniseriate filaments that developed into fan-shaped blades. Only asexual reproduction was observed; this took place through recycling of blades by germination of zooids. Phylogenetic analysis based on rDNA internal transcribed spacer (ITS) sequences showed that G. brasiliensis specimens formed a monophyletic group closely related to Monostroma nitidum and two unidentified monostromatic species from Japan and Tanzania. The genus Monostroma was polyphyletic in our analysis. ITS sequences also confirmed the presence of a second monostromatic species of Ulotrichales in the Brazilian coast, Gayralia oxysperma. There were overlapping morphological and life history traits between G. brasiliensis and G. oxysperma. However, these two species were clearly divergent based on ITS sequences and ontogeny.

Dictyota menstrualis (Hoyt) Schnetter, Horning & Weber-Peukert (Dictyotales, Phaeophyceae) was studied for the production of oil-based bioproducts and co-products. Experiments were performed to evaluate the effect of carbon dioxide (CO2) concentration, under nitrogen (NO3 (-)) limiting and saturation conditions, on growth rate (GR), photosynthesis, as well as nitrate reductase (NR), carbonic anhydrase (CA), and Rubisco activities. In addition, the biochemical composition of D. menstrualis under these conditions was estimated. GR, protein content, and N content in D. menstrualis were higher in treatments containing NO3 (-), irrespective of CO2 addition. However, when CO2 was added to medium saturated with NO3 (-), values of maximum photosynthesis, Rubisco, and NR activity, as well as total soluble carbohydrates and lipids, were increased. CA activity did not vary under the different treatments. The fatty acid profile of D. menstrualis was characterized by a high content of polyunsaturated fatty acids, especially the omega-3 fatty acids, making it a possible candidate for nutraceutical use. In addition, this species presented high GR, photosynthetic rate, and fatty acid content, highlighting its economic importance and the possibility of different biotechnological applications.

Photosynthesis at high latitudes demands efficient strategies of light utilization to maintain algal fitness and performance. The fitness, and physiological adaptation, of a plant or algae species depends in part on the abundance and efficiency of the pigments it can produce to utilize the light resource from its environment. We quantified pigment composition and concentration in six species of the brown macroalgal genus Desmarestia, collected from sub-Antarctic sites (Strait of Magellan, Beagle Channel–Cape Horn Province) and sites on the Antarctic Peninsula and adjacent islands. Sub-Antarctic Desmarestia species exhibited lower concentrations of chlorophyll a , chlorophyll c and fucoxanthin than endemic Antarctic species. Antarctic samples of D. menziesii and D. antarctica collected along a decreasing latitudinal gradient showed spatial and interspecific differences in light-harvesting pigment composition. Our results suggest distinct physiological adjustments in Desmarestia species in response to heterogeneous abiotic environmental conditions. The marine sub-Antarctic and Antarctic ecosystems are characterized by harsh environments (e.g., extreme irradiance, photoperiod, temperature, salinity) to which the physiology of macroalgal species must adapt. Keywords: Macroalgae; Phaeophyceae; photosynthesis; physiology; environmental heterogeneity; Chile. (Published: 4 August 2016) Citation: Polar Research 2016, 35 , 29383,http://dx.doi.org/10.3402/polar.v35.29383

The selection of seaweed species for their use as biofilters should be based on the knowledge of their nutrient requirements and tolerance to wide variations of nutrient concentrations. Therefore, tolerance and the physiological capabilities of Hypnea cervicornis J. Agardh (Gigartinales, Rhodophyta) to growth under nitrate, ammonium, and phosphate variations and to assimilate them into soluble proteins and photosynthetic pigments were evaluated in laboratory conditions. Treatments were composed of sterilized seawater enriched with 25 % von Stosch solution (without nitrogen and phosphorus), and nitrate or ammonium and phosphate were added in combination of 100:1 and 10:1 nitrogen/phosphorus (N/P). Nitrate concentrations varied from 0 to 500 μM, and ammonium concentrations varied from 0 to 50 μM. Growth rates of H. cervicornis increased linearly with addition of ammonium, but with nitrate addition, growth varied following a saturation kinetic, and the highest growth rate (14.45 % d−1) was observed in 200 μM of N/P ratio of 10:1. An excess of nutrients was accumulated as proteins and phycobiliproteins (mainly as allophycocyanin and phycoerythrin) at higher phosphate availability (N/P ratio of 10:1), and H. cervicornis tolerated the highest ammonium and nitrate concentrations (50 and 500 μM, respectively). These physiological responses suggest that this species could be used as biofilter for nutrient removal in eutrophicated seawater and could be cultivated in integrated multitrophic aquaculture systems.

The success of seaweed cultivation depends on the scientific control of the tolerance limits and the optimal physiological conditions that affect the spore germination and the early development of algal species. In order to establish cultivation techniques for spores of Hidropuntia caudata (J. Agardh) Gurgel & Fredericq, the effects of irradiance, salinity, and temperature on the carpospore germination and carposporeling development were evaluated under laboratory conditions. Five photon flux densities (PFD, from 18 to 200 µmol photons m-2s-1), six salinity values (from 7 to 55 psu), and four temperatures (from 20 ºC to 35 ºC) were investigated. The level of irradiance caused significant differences in the growth, in the following order: 200±5 > 100±5 62.5±2.5 > 30±1.5 > 18±1 µmol of photons m-2s-1, but they did not inhibit the carposporeling development. Maximum growth occurred under 35 psu, while at 15 psu the formation of carposporeling erect axis was limited. The optimal temperature for growth was 25 ºC, while at 35 ºC the spores died. These results show the importance of previous knowledge on the tolerance limits and optimal conditions for sporeling development of H. caudata for the implementation of an aquaculture program.

Climate change can be associated with variations in the frequency and intensity of extreme temperatures and precipitation events on the local and regional scales. Along coastal areas, flooding associated with increased occupation has seriously impacted products and services generated by marine life, in particular the biotechnological potential that macroalgae hold. Therefore, this paper analyzes the available information on the taxonomy, ecology and physiology of macroalgae and discusses the impacts of climate change and local stress on the biotechnological potential of Brazilian macroalgae. Based on data compiled from a series of floristic and ecological works, we note the disappearance in some Brazilian regions of major groups of biotechnological interest. In some cases, the introduction of exotic species has been documented, as well as expansion of the distribution range of economically important species. We also verify an increase in the similarities between the Brazilian phycogeographic provinces, although they still remain different. It is possible that these changes have resulted from the warming of South Atlantic water, as observed for its surface in southeastern Brazilian, mainly during the winter. However, unplanned urbanization of coastal areas can also produce similar biodiversity losses, which requires efforts to generate long-term temporal data on the composition, community structure and physiology of macroalgae.

Seaweeds are photosynthetic organisms important to their ecosystem and constitute a source of compounds with several different applications in the pharmaceutical, cosmetic and biotechnology industries, such as triacylglycerols, which can be converted to fatty acid methyl esters that make up biodiesel, an alternative source of fuel applied in economic important areas. This study evaluates the fatty acid profiles and concentrations of three Brazilian seaweed species, Hypnea musciformis (Wulfen) J.V. Lamouroux (Rhodophya), Sargassum cymosum C. Agardh (Heterokontophyta), and Ulva lactuca L. (Chlorophyta), comparing three extraction methods (Bligh & Dyer - B&D; AOAC Official Methods - AOM; and extraction with methanol and ultrasound - EMU) and two transesterification methods (7% BF3 in methanol - BF3; and 5% HCl in methanol - HCl). The fatty acid contents of the three species of seaweeds were significantly different when extracted and transesterified by the different methods. Moreover, the best method for one species was not the same for the other species. The best extraction and transesterification methods for H. musciformis, S. cymosum and U. lactuca were, respectively, AOM-HCl, B&D-BF3 and B&D-BF3/B&D-HCl. These results point to a matrix effect and the method used for the analysis of the fatty acid content of different organisms should be selected carefully.

Different environmental factors play important roles in the growth, reproduction, and distribution of marine macroalgae. We investigated the effects of temperature, salinity, irradiance, and nutrients on the growth of carposporelings and tetrasporophytes of Gracilaria domingensis. Carposporelings grew at temperatures of 25°C and 30°C, but they did not survive at 15°C and 20°C. In contrast, tetrasporophytes grew over a wide range of temperatures (15–30°C) with optimum growth between 20°C and 25°C. Both carposporelings and tetrasporophytes tolerated a wide range of salinity (25–60 and 10–50, respectively), but carposporelings were more sensitive to lower salinities (10–20), while tetrasporophytes were more sensitive to higher salinities (60). The highest growth rates in basal discs of carposporelings occurred when they were grown in 25% strength von Stosch enriched medium (VSES) with an illumination of 150 μmol photons m-2 s-1; erect fronds grew best in 25% and 50% strength VSES with illumination of 100 μmol photons m-2 s-1. The VSES strength did not influence the growth of tetrasporophytes of G. domingensis. Highest growth rates of tetrasporophytes occurred at 100 μmol photons m-2 s-1. These results demonstrate very different physiological responses between carposporelings and tetrasporophytes of G. domingensis and, as such, they offer guidelines for the selection of potential areas for the cultivation of the species.

In the present study, the daily relative growth rates (DRGR, in percent per day) of the red macroalga Gracilaria domingensis in synthetic seawater was investigated for the combined influence of five factors, i.e., light (L), temperature (T), nitrate (N), phosphate (P), and molybdate (M), using a statistical design method. The ranges of the experimental cultivation conditions were T, 18–26°C; L, 74–162 μmol photons m−2 s−1; N, 40–80 μmol L−1; P, 8–16 μmol L−1; and M, 1–5 nmol L−1. The optimal conditions, which resulted in a maximum growth rate of ≥6.4% d−1 from 7 to 10 days of cultivation, were determined by analysis of variance (ANOVA) multivariate factorial analysis (with a 25 full factorial design) to be L, 74 μmol photons m−2 s−1; T, 26°C; N, 80 μmol L−1; P, 8 μmol L−1; and M, 1 nmol L−1. In additional, these growth rate values are close to the growth rate values in natural medium (von Stosch medium), i.e., 6.5–7.0% d−1. The results analyzed by the ANOVA indicate that the factors N and T are highly significant linear terms, X L, (α = 0.05). On the other hand, the only significant quadratic term (X Q) was that for L. Statistically significant interactions between two different factors were found between T vs. L and N vs. T. Finally, a two-way (linear/quadratic interaction) model provided a quite reasonable correlation between the experimental and predicted DRGR values (R adjusted 2 = 0.9540).

Marine environment is one of the most important sources regarding natural products research. Besides, marine microorganisms have been denominated as a talented natural source for discovery of new leads. Although the association of macroalgae and fungi has been described regarding ecological issues, there is a lack of studies about marine seaweed endophytic fungi. In this context, the goal of this study was to evaluate cytotoxic, antifungal and antibacterial activities of endophytic fungi isolated from the Brazilian marine seaweed Bostrychia tenella (J.V. Lamouroux) J. Agardh (Ceramiales, Rhodophyta). Forty-five endophytic microorganism strains were isolated from B. tenella. Crude extracts and organic fractions of ten selected strains were obtained after growth in rice medium. Samples were evaluated for cytotoxicity, antifungal and antibacterial assays. Penicillium strains showed positive results in a diversity of assays, and other five strains were active in at least one test. In addition, cytochalasin D was isolated from Xylaria sp. This alga is composed of a microbiological potential, since its endophytic strains exhibited remarkable biological properties. Moreover, cytochalasin D isolation has confirmed chemical potential of marine endophytic strains. This is the first study in which cultured fungi isolates from the Brazilian macroalga B. tenella were evaluated concerning biological properties. Results corroborated that this species could be a pharmaceutical source from marine environment. Furthermore, Acremonium implicatum is being firstly described as marine endophyte and Xylaria sp., Trichoderma atroviride and Nigrospora oryzae as marine seaweed endophytes. Thus, this work reports the first study relating detailed isolation, cultivation and biological evaluation (cytotoxic, antifungal and antibacterial) of endophytes Penicillium decaturense and P. waksmanii from the Brazilian marine red alga B. tenella. We are also reporting the isolation of cytochalasin D, a known antitumor and antibiotic compound, from Xylaria sp. strain. Despite widespread prevalence in terrestrial and marine habitats, this present work describes the first occurrence of cytochalasin D as a metabolite from marine seaweed endophyte. Keywords: Brazilian seaweed, Cytochalasin D, Penicillium, Xylaria

Made available in DSpace on 2013-08-28T14:11:32Z (GMT). No. of bitstreams: 1 WOS000294249100071.pdf: 377708 bytes, checksum: 4e0ffce93f3155c6b0ea3b0e150b800c (MD5) Made available in DSpace on 2013-09-30T18:06:16Z (GMT). No. of bitstreams: 2 WOS000294249100071.pdf: 377708 bytes, checksum: 4e0ffce93f3155c6b0ea3b0e150b800c (MD5) WOS000294249100071.pdf.txt: 30207 bytes, checksum: 0be35f2852d8de191beb57eb44b5a30f (MD5) Previous issue date: 2011-08-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:24:19Z No. of bitstreams: 2 WOS000294249100071.pdf: 377708 bytes, checksum: 4e0ffce93f3155c6b0ea3b0e150b800c (MD5) WOS000294249100071.pdf.txt: 30207 bytes, checksum: 0be35f2852d8de191beb57eb44b5a30f (MD5) Made available in DSpace on 2014-05-20T13:24:19Z (GMT). No. of bitstreams: 2 WOS000294249100071.pdf: 377708 bytes, checksum: 4e0ffce93f3155c6b0ea3b0e150b800c (MD5) WOS000294249100071.pdf.txt: 30207 bytes, checksum: 0be35f2852d8de191beb57eb44b5a30f (MD5) Previous issue date: 2011-08-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The present study reports the Gas Chromatography-Mass Spectrometry (GC-MS) evaluation of the hexanes and dichloromethane fractions from extracts of the red alga Centroceras clavulatum (C. Agardh) Montagne. Twenty three compounds were identified, totaling ca. 42% of both fractions (0.18 g mass extract). The main constituents of the fractions were hexadecanoic acid (17.6%) and pentadecanoic acid (15.9%). Several secondary metabolites with interesting biological activity, such as (-)-loliolide, neophytadiene, phytol were identified. In addition, several classes of secondary metabolites, including phenolic compounds (e.g., phenylacetic acid), terpene derivatives, fatty acids, halogenated compound (e.g., 2-chlorocyclohexenol), lignoids, steroids, esters, amides (e.g., hexadecanamide), ketones, carboxylic acids, aldehydes and alcohols were observed. The occurrence of several of these structural classes is described for the first time in this species. The same fractions analyzed by GC-MS, and a separate set of polar fractions, were evaluated against two life cycle stages (epimastigote and trypomastigote forms) of the protozoan Trypanosoma cruzi and against phytopatogenic fungi Cladosporium cladosporiodes and C. sphaerospermum. The dichloromethane fraction was active against both T. cruzi forms (epimastigote IC(50) = 19.1 mu g.mL(-1) and trypomastigote IC(50) = 76.2 mu g.mL(-1)). The hexanes and ethyl acetate fractions also displayed activity against both fungi species (200 mu g) by TLC-bioautography. Fac Ciencias Farmaceut Ribeirao Preto USP, Dept Quim & Fis, BR-14040903 Ribeirao Preto, SP, Brazil Dept Ciencias Biol UNESP, Fac Ciencias Farmaceut Araraquara, BR-14801902 Araraquara, SP, Brazil Fac Ciencias Farmaceut Ribeirao Preto USP, Dept Anal Clin Toxicol & Bromatol, BR-14040903 Ribeirao Preto, SP, Brazil Inst Bot, Nucleo Pesquisas Fisiol & Bioquim Vegetal, BR-04301012 São Paulo, Brazil Inst Bot, Nucleo Pesquisas Ficol, BR-04301012 São Paulo, Brazil Dept Ciencias Biol UNESP, Fac Ciencias Farmaceut Araraquara, BR-14801902 Araraquara, SP, Brazil

) Recursos de Divisa˜o Microbianos, Centro Pluridisciplinar de Pesquisas Qumicas, Biolo´gicas eAgrcolas, CPQBA, Universidade Estadual de Campinas, Rua Alexandre Casellato, 999,CEP 13140-000, Paulnia-SP, BrazilThe biocatalytic reduction of acetophenone derivatives was exploited by using algal biomass fromBostrychia radicans and B. tenella producing exclusively (S)-2-phenylethanols with high enantiomericexcess (>99% ee). Bacterial populations associated with algal biomass were identified as the Bacillusgenus. This report deals with the first investigations involving the use of marine bacteria associated withB. radicans and B. tenella marine algae for the biocatalytic reduction of acetophenone derivatives.

Endogenous cytokinins, auxins, and abscisic acid (ABA) were identified and quantified in 11 red algae collected from the Brazilian coast. Field materials and two isolates cultured in the laboratory were extracted with various solvents and buffers containing a mixture of appropriate internal standards, purified by solid-phase extraction followed by immunoaffinity chromatography, and analyzed by liquid chromatography–tandem mass spectrometry. Isoprenoid cytokinins (free and conjugated forms of isopentenyladenine [iP], cis-zeatin [cZ], and trans-zeatin [tZ]) were detected in all species with concentrations of cZ and iP forms being higher than tZ forms. Dihydrozeatin (DHZ) and its metabolites were only detected at very low levels in nine of the studied species. Aromatic cytokinins (6-benzylaminopurine [BA], ortho- and meta-topolin [oT and mT]) were not detected in any of the samples. The cytokinin profile of Chondracanthus teedei (Mert. ex Roth) Kutz. was distinct in comparison to other species with para-topolin (pT) derivatives detected in low concentrations. The main auxins present in all species were free indole-3-acetic acid (IAA) and indole-3-acetamide (IAM). Indole-3-ethanol (IEt), indole-3-acetyl glutamic acid (IAGlu), and indole-3-acetyl leucine (IALeu) were detected in a few species at low concentrations. ABA was present in all species analyzed except for Hypnea nigrescens Grev. ex J. Agardh. No ABA conjugates were detected in any species. These results confirm that cytokinins, auxins, and ABA were common constituents in red seaweeds, with this being the first report of the occurrence of ABA in Rhodophyta. The complexity of the hormone profiles suggests that plant hormones play a role in regulating physiological processes in Rhodophyta.

Specimens of the red alga Bostrychia tenella J. Agardh (Rhodomelaceae, Ceramiales) were collected from the Sao Paulo coast and submitted to room temperature solvent extraction. The resulting extract was fractionated by partitioning with organic solvent. The n-hexane (BT-H) and dichloromethane (BT-D) fractions showed antiprotozoal potential in biological tests with Trypanosoma cruzi and Leishmania amazonensis and presented high activity in an antifungal assay with the phytopathogenic fungi Cladosporium cladosporioides and Cladosporium sphaerospermum . Chromatography methods were used to generate subfractions from BT-H (H01 to H11) and from BT-D (D01 to D19). The subfractions were analyzed by gas chromatography–mass spectrometry (GC/MS), and the substances were identified by retention index (Kovats) and by comparison to databases of commercial mass spectra. The volatile compounds found in marine algae were identified as fatty acids, low molecular mass hydrocarbons, esters and steroids; some of these have been previously described in the literature based on other biological activities. Moreover, uncommon substances, such as neophytadiene were also identified. In a trypanocidal assay, fractions BT-H and BT-D showed IC 50 values of 16.8 and 19.1 μg/mL, respectively, and were more active than the gentian violet standard (31 μg/mL); subfractions H02, H03, D01 and D02 were active against L. amasonensis , exhibiting IC 50 values of 1.5, 2.7, 4.4, and 4.3 μg/mL, respectively (standard amphotericin B: IC 50 = 13 μg/mL). All fractions showed antifungal potential. This work reports the biological activity and identification of compounds by GC/MS for the marine red alga B. tenella for the first time.

Effects of nitrate availability in two culture media (von Stosch (VSES), and artificial ASP 12-NTA), and nitrogen sources (seawater enriched with nitrate, ammonium or urea in concentrations ranging from zero to 30 µM) were evaluated in two brown morphs (BR-1, BR-2), one light-green morph (LG) and one dark-green morph (DG) of Hypnea musciformis (Wulfen) J.V. Lamour. Higher growth rates of the four morphs were observed in VSES medium. However, artificial ASP12-NTA medium induced tetrasporangium development in DG morph. Growth rates of the four colour morphs followed kinetic of saturation-type nutrient uptake in treatments with urea. In contrast, growth rates of BR-1, BR-2 and LG morphs were inversely proportional to ammonium concentrations, and those higher than 15 µM were lethal. Growth responses of colour morphs of H. musciformis showed intraspecific variations, and they could be used as bioindicators of nitrogen pollution in marine environment by their low tolerance to ammonium. Efeitos da disponibilidade de nitrato em dois tipos de meio de cultura (meio von Stosch (VSES) e meio artificial ASP 12-NTA), e fonte de nitrogênio (água do mar enriquecida com nitrato, amônio e uréia em concentrações de zero a 30 µM) foram avaliados em dois morfos marrons (BR-1, BR-2), um morfo verde-claro (LG) e um morfo verde-escuro (DG) de Hypnea musciformis (Wulfen) J.V. Lamour. As maiores taxas de crescimento dos quatro morfos foram observadas em meio VSES. Entretanto, o meio artificial ASP12-NTA induziu o desenvolvimento de tetrasporângios no morfo DG. As taxas de crescimento dos quatro morfos variaram segundo uma cinética de saturação nos tratamentos contendo uréia. Por outro lado, as taxas de crescimento dos morfos BR-1, BR-2 e LG foram inversamente proporcionais às concentrações de amônio, e aquelas maiores do que 15 µM foram letais. As respostas em crescimento dos quatro morfos de H. musciformis apresentaram variações intraespecíficas, e estes morfos podem ser bioindicadores de poluição por nitrogênio em ambientes marinhos devido à sua baixa tolerância ao amônio.

Four species of marine benthic algae (Laurencia filiformis, L. intricata, Gracilaria domingensis and G. birdiae) that belong to the phylum Rhodophyta were collected in Espirito Santo State, Brazil and investigated concerning their biochemical composition (fatty acid, total lipid, soluble proteins, amino acid and ash). The total content of lipid (% dry weight) ranged from 1.1% to 6.2%; fatty acid from 0.7% to 1.0%; soluble protein from 4.6% to 18.3%, amino acid from 6.7% to 11.3% and ash from 22.5% to 38.4%. Judging from their composition, the four species of algae appear to be potential sources of dietary proteins, amino acids, lipids and essential fatty acids for humans and animals.

Tissue culture techniques were applied for micropropagation of the red alga Kappaphycus alvarezii in order to select the best strain and experimental system for in vitro culture. Five strains were tested: brown (BR), green (GR) and red (RD) tetrasporophytes, brown female gametophyte (BFG), and a strain originating from tetraspore germination (“Edison de Paula”, EP). The effects of three culture media were tested on callus formation, regeneration from explants and from callus in the three tetrasporophytic and EP strains: seawater enriched with half-strength of von Stosch’s (VS 50) and Guillard & Ryther’s (F/2 50) solutions, plus synthetic ASP 12-NTA medium, with or without gelling agent. Explants of the EP strain were treated with glycerol and the phytoregulators indole-3-acetic acid (IAA); 2,4-diclorophenoxyacetic acid (2,4-D); and benzylaminopurine (BA), alone or in combination. The effects of colchicine (0.01%) during 24, 48, 72 hours and 14 days were analyzed in the BFG and EP strains. The EP strain showed the highest percentage of explants forming callus and regeneration from explants in VS 50, indicating its high potential for micropropagation in comparison to the other strains. Regeneration from callus was very rare. Treatments with glycerol and IAA:BA (5:1 mg L−1) stimulated the regeneration from explants. Significant differences were observed in the percentages of regeneration of EP strain explants treated with colchicine for 14 days. Our results indicate that IAA and BA stimulated the regeneration process, and that colchicine produced explants with high potential for regeneration, being useful for improving the micropropagation of K. alvarezii.

Gayralia K.L. Vinogr. is a monostromatic green alga of commercial importance in the southern Brazil, and its cultivation is being considered. This paper reports some basic aspects of the biology of this poorly known genus. Two populations of Gayralia spp., from outer and inner sectors of Paranagua Bay, showed an asexual life history with a distinct pattern of thallus ontogeny. In one population (Gayralia sp. 1), zooids developed an expanded monostromatic blade directly, while in the other (Gayralia sp. 2) zooids produced an intermediate saccate stage, before giving rise to a monostromatic blade. Thalli of the two species differ in size and in cell diameter. The effects of temperature (16–30°C), irradiance (50–100 μmol photons m−2 s−1), and salinity (5–40 psu) on the growth of both populations were assessed. Plantlets of Gayralia sp. 1 from in vitro cultures showed a broader tolerance to all salinity and irradiance levels tested, with the highest growth rate (GR; mean 17% day−1) at 21.5°C and 100 μmol photons m−2 s−1. Plantlets of Gayralia sp. 1 collected during the winter in the field showed higher GR, ranging from 5% day−1 to 7.5% day−1 in salinities from 20 to 40 psu, and 2.0% day−1 and 4.3% day−1 for plantlets collected during the summer. Gayralia sp. 2 from the field showed highest GR at salinity of 15 psu. These results suggest distinct physiological responses of the two species, in accordance with their distribution: Gayralia sp. 2 is limited to the inner areas of the estuary, while Gayralia sp. 1 grows in outer areas, where salinity values are higher than 20 psu. These data indicate that Gayralia sp. 1 has a higher potential for aquaculture than Gayralia sp. 2 due to its larger thalli, higher GR, and wider tolerance to environmental variations.