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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.

Species of the genus Gracilaria are widely distributed around the world, and many are wild harvested and cultivated for phycocolloid production (agar) and human food. This study investigated the growth performance of three color strains of Gracilaria domingensis in an integrated organic system. The three chromatic variants (red, green, and brown) were cultured in a shrimp farm at two depths (surface and 20 cm). The highest relative growth rates were obtained in the first week of cultivation for all three strains studied. Although the growth rates and biomass were slightly higher at a depth of 20 cm, significant differences were not observed at different depths (p

Radiation continuously varies in the environment, exposing phototrophic organisms to diverse compositions and ratios among photosynthetically active radiation (PAR), UV-A (Ultraviolet A radiation) and UV-B (Ultraviolet B radiation). In this sense, UV radiation can control, either positively or negatively, the physiology and metabolism of marine organisms in intertidal areas. Our study focused on the exposure of Gracilaria tenuistipitata to variable combinations of radiation, evaluating its physiology, photoprotective strategies and DNA damage under each condition. To accomplish this, algal apical fragments were acclimated to three radiation treatments (PAR, PAR + UV-A and PAR + UV-A + UV-B) for one week. Thereafter, PAR-acclimated samples were moved to PAR (control), PAR + UV-A + UV-B and PAR + UV-B. PAR + UV-A-acclimated samples were moved to PAR + UV-A (control), PAR + UV-A + UV-B and PAR + UV-B, and PAR + UVR-acclimated thalli were placed in PAR + UV-A + UV-B (control), PAR + UV-B and PAR. Samples remained in these conditions for a period of 48 h continuously. Photosynthetic parameters from chlorophyll a fluorescence were evaluated, as well as growth rates, mycosporine-like amino acids, chlorophyll a, and carotenoid contents. In addition, DNA damage was assessed by detecting cyclobutane pyrimidin dimer. Expression of photolyases, ascorbate peroxidase and gluthatione peroxidase was also analyzed at the end of experimental period. Mycosporine-like amino acids were stimulated by UV radiation. DNA damage occurred only when UV-B was provided separately. In some cases, photoacclimation procedures were activated, while in others, it was not enough. In other words, although some tolerance was observed, the species could suffer the consequences of excessive energy present in some specific treatments, e.g., PAR + UV-B. After exposure to variable radiation, it was concluded that our model organism presented acclimation depending of spectral availability, including regulation of photoprotective strategies.

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.

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).

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.

The phycoerythrin-deficient strain (green phenotype) of Hypnea musciformis (Rhodophyta) originated from a green branch, which had arisen as a spontaneous mutation in a wild plant (brown phenotype) collected from the Brazilian coast. The present study describes the growth responses to irradiance, photoperiod and temperature variations, pigment contents, and photosynthetic characteristics of the brown and green strains of H. musciformis. The results showed that growth rates increased as a function of irradiance (up to 40 μmol photons m �2 s �1 ) but, with further increase in irradiance (from 40 to 120 μmol photons m �2 s �1 ), became light-saturated and remained almost unchanged. The highest growth rates of the brown and green strains were observed in temperatures of 20-25°C under long (14:10 h LD) and short (10:14 h LD) photoperiods. The brown strain had higher growth rates than the green strain in the short photoperiod, which could be related to the high concentrations of phycobiliproteins. Phycoery- thrin was not detected in the green strain. The brown strain had higher concentrations of allophycocyanin and phycoerythrin in the short photoperiod while the green strain had higher concentrations of phycocya- nin. The brown strain presented higher photosynthetic efficiency (α), and lower saturation parameter (Ik) and compensation irradiance (Ic) than the green strain. The brown strain exhibited the characteristics of shade-adapted plants, and its higher value of photosynthetic efficiency could be attributed to the higher phycoerythrin concentrations. Results of the present study indicate that both colour strains of H. musciformis could be selected for aquaculture, since growth rates were similar (although in different optimal light conditions), as the green strain seems to be adapted to higher light levels than the brown strain. Furthermore, these colour strains could be a useful experimental system to understand the regu- lation of biochemical processes of photosynthesis and metabolism of light-harvesting pigments in red algae.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:57:49Z No. of bitstreams: 1 S0102-695X2011000200022.pdf: 1244686 bytes, checksum: ac76772cb0e2c392093103ebc93c4a2c (MD5) Made available in DSpace on 2013-08-22T18:57:49Z (GMT). No. of bitstreams: 1 S0102-695X2011000200022.pdf: 1244686 bytes, checksum: ac76772cb0e2c392093103ebc93c4a2c (MD5) Previous issue date: 2011-04-01 Made available in DSpace on 2013-09-30T19:52:54Z (GMT). No. of bitstreams: 2 S0102-695X2011000200022.pdf: 1244686 bytes, checksum: ac76772cb0e2c392093103ebc93c4a2c (MD5) S0102-695X2011000200022.pdf.txt: 37693 bytes, checksum: 730e23ce4fc759902fa0d21fc21cad99 (MD5) Previous issue date: 2011-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:13:45Z No. of bitstreams: 2 S0102-695X2011000200022.pdf: 1244686 bytes, checksum: ac76772cb0e2c392093103ebc93c4a2c (MD5) S0102-695X2011000200022.pdf.txt: 37693 bytes, checksum: 730e23ce4fc759902fa0d21fc21cad99 (MD5) Made available in DSpace on 2014-05-20T15:13:45Z (GMT). No. of bitstreams: 2 S0102-695X2011000200022.pdf: 1244686 bytes, checksum: ac76772cb0e2c392093103ebc93c4a2c (MD5) S0102-695X2011000200022.pdf.txt: 37693 bytes, checksum: 730e23ce4fc759902fa0d21fc21cad99 (MD5) Previous issue date: 2011-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) In Brazil, Hypnea musciformis is the main raw material for carrageenan production and the knowledge of nitrogen and phosphorus metabolism in algae is critical for the success of cultivation because these elements can limit seaweed productivity. Thus, the objective of this study was to evaluate the effects of nitrate (zero to 100 μM) and nitrate plus phosphate (zero to 25 μM) availabilities on the growth, the contents of photosynthetic pigments (phycobiliproteins and chlorophyll a) and proteins, and the photosynthesis and respiration of the brown (BR) and light green (LG) strains of H. musciformis. The results revealed metabolic differences between the colour strains of H. musciformis for nitrogen metabolism: upon nitrate addition, the LG strain stored nitrogen mainly as proteins, while the BR strain stored it as proteins and pigments. Moreover, the respiration of the LG strain and the photosynthesis of the BR strain increased with nitrate concentrations, indicating that the BR strain fixed more photosynthetic carbon than the LG strain. Secretaria de Estado do Meio Ambiente Instituto de Botânica Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e Botânica Universidade de São Paulo Instituto de Química Departamento de Bioquímica Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e Botânica

BACKGROUND: Algae species have been used as an important source of food because they are highly nutritive considering their vitamin, protein, mineral, fiber, essential fatty acid and carbohydrate contents. However, a large number of seaweeds have been poorly studied, especially Brazilian species. Two red macroalgae species from the Brazilian coast (Plocamium brasiliense and Ochtodes secundiramea) were assessed with respect to their total lipid, fatty acid, total nitrogen, protein, amino acid and total carbohydrate contents. RESULTS: The total lipid contents (dry weight) were 36.3 and 35.4 g kg−1; fatty acid contents were 9.3 and 12.1 g kg−1; total nitrogen contents were 37.4 and 24.9 g kg−1; protein contents were 157.2 and 101.0 g kg−1; amino acid contents were 127.5 and 91.4 g kg−1; and total carbohydrate contents were 520.3 and 450.7 g kg−1 for P. brasiliense and O. secundiramea, respectively. CONCLUSION: Considering these compositions, both algae species were determined to have sources of protein, essential amino acids and carbohydrates similar to the edible seaweeds Laminaria japonica and Palmaria palmata. Copyright © 2011 Society of Chemical Industry

Hypnea musciformis (Wulfen in Jacqu.) J.V. Lamour. is the main source for carrageenan production in Brazil and strains with selected characteristics could improve the production of raw material. The effects of kinetin on growth rates, morphology, protein content, and concentrations of pigments (chlorophyll a, phycoerythrin, phycocyanin, and allophycocyanin) were assessed in the wild strain (brown phenotype) and in the phycoerythrin-deficient strain (green phenotype) of H. musciformis. Concentrations of kinetin ranging from 0 to 50 μM were tested in ASP 12-NTA synthetic medium with 10 μM nitrate (N-limited) and 100 μM nitrate (N-saturated). In N-limited condition, kinetin stimulated growth rates of the phycoerythrin-deficient strain and formation of lateral branches in both colour strains. Kinetin stimulated protein biosynthesis in both strains. However, differences between both nitrogen conditions were significant only in the phycoerythrin-deficient strain. In the wild strain, effects of kinetin on concentrations of phycobiliproteins were not significant in both nitrogen conditions, except for chlorophyll content. However, the phycoerythrin-deficient strain showed an opposite response, and kinetin stimulated the phycobiliprotein biosynthesis, with the highest concentrations of phycoerythrin in N-saturated medium, while the highest concentrations of allophycocyanin and phycocyanin were observed in N-limited medium. These results indicate that the effects of kinetin on growth, morphology, protein and phycobiliprotein contents are influenced by nitrogen availability, and the main nitrogen storage pools in phycoerythrin-deficient strain of H. musciformis submitted to N-limited conditions were phycocyanin and allophycocianin, the biosynthesis of which was enhanced by kinetin.