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In the present study, we surveyed the distribution and diversity of fungal assemblages associated with 10 species of marine animals from Antarctica. The collections yielded 83 taxa from 27 distinct genera, which were identified using molecular biology methods. The most abundant taxa were Cladosporium sp. 1, Debaryomyces hansenii, Glaciozyma martinii, Metschnikowia australis, Pseudogymnoascus destructans, Thelebolus cf. globosus, Pseudogymnoascus pannorum, Tolypocladium tundrense, Metschnikowia australis, and different Penicillium species. The diversity, richness, and dominance of fungal assemblages ranged among the host; however, in general, the fungal community, which was composed of endemic and cold-adapted cosmopolitan taxa distributed across the different sites of Antarctic Peninsula, displayed high diversity, richness, and dominance indices. Our results contribute to knowledge about fungal diversity in the marine environment across the Antarctic Peninsula and their phylogenetic relationships with species that occur in other cold, temperate, and tropical regions of the World. Additionally, despite their extreme habitats, marine Antarctic animals shelter cryptic and complex fungal assemblages represented by endemic and cosmopolitan cold-adapted taxa, which may represent interesting models to study different symbiotic associations between fungi and their animal hosts in the extreme conditions of Antarctica.

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.

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.

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.

Made available in DSpace on 2019-10-06T16:49:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01. Added 1 bitstream(s) on 2019-10-09T18:35:39Z : No. of bitstreams: 1 S2179-975X2019000100316.pdf: 1091572 bytes, checksum: af9f3c03e6ecea4a3c121e319fca9cfa (MD5) Aim: The response of mixed cultures and monocultures of Pseudopediastrum boryanum (Turpin) E. Hegewald and Scenedesmus obliquus (Turpin) Kützing was assessed in the laboratory at three different temperatures: 20, 30 and 40 °C. The change in biomass and biochemical composition of these cultures was evaluated. Methods: Microalgae were placed in a batch culture over 21-days in ASM1 medium. Cell density was directly counted every two days using a Fuchs-Rosenthal hemocytometer. Chlorophyll ‘a’ and total carotenoids were extracted twice. Protein, carbohydrate, total lipid and fatty acid contents were determined at the end of the experiment. Results: Cultures grown in 40 °C exhibited no growth. However, there was increased cell density (13.6 x 106 cell.mL-1) and biomass (55 g.L-1) in the S. obliquus monoculture at 30 °C. High protein concentrations (672.6 mg.g-1) were observed in monocultures P. boryanum and S. obliquus at 20 °C treatments. There were high carbohydrate concentrations (6.17 mg.g-1) in P. boryanum unialgal at 30 °C. There was no significant difference in total lipid content between S. obliquus (95.5 mg.g-1), P. boryanum (96.3 mg.g-1) and the mixed culture at 20 °C (105.3 mg.g-1). FAMEs varied significantly regarding the number of unsaturated components, which predominantly consisted of fatty acids with two or more unsaturated bonds. Conclusions: The biomass of the treatments analyzed was rich in proteins and essential fatty acids (such as linolenic acid), yet low in carbohydrate content, suggesting its potential use as a food supplement. Our results indicate that mixed culture of P. boryanum and S. obliquus was inefficient in cultivating biomass or biochemical compounds as compared to the unialgal cultivations. However, algae grown together showed better stability in their biochemical composition in response to changes in temperature, an important factor for microalgae production in open ponds and in food safety measures. These results suggest the consortia among different species of microalgae should be tested to determine better methodologies for the production of biomass and metabolites with greater stability towards environmental factors. Centro de Ciências Humanas e Naturais Universidade Federal do Espírito Santo UFES, Av. Fernando Ferrari, 514, Goiabeiras Instituto de Química Departamento de Bioquímica Universidade de São Paulo – USP, Av. Prof. Lineu Prestes, 748, Vila Universitária Departamento de Engenharia de Pesca Universidade Estadual de São Paulo – UNESP, Av. Nelson Brihi Badur, 430, Vila Tupy Departamento de Engenharia de Pesca Universidade Estadual de São Paulo – UNESP, Av. Nelson Brihi Badur, 430, Vila Tupy

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.

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.

Neste trabalho, foi estudado o potencial biotecnológico, com ênfase na produção de biodiesel, de 25 espécies de macroalgas marinhas pertencentes às divisões Rhodophyta, Chlorophyta e Heterokontophyta coletadas no litoral brasileiro, avaliando-se a sua composição bioquímica e a sua taxa de fotossíntese. Também foram realizados estudos com 6 espécies de macroalgas coletadas na Baía do Almirantado, na Península Antártica, para comparar os resultados apresentados por esses organismos, que habitam um ambiente de condições extremas e adversas. Para a análise bioquímica, foram quantificados os pigmentos (clorofila a, para todos os grupos de macroalgas, e ficobiliproteínas -aloficocianina, ficocianina e ficoeritrina-, para as algas vermelhas), as proteínas e carboidratos solúveis totais e os lipídeos totais e ácidos graxos. As espécies Dictyota menstrualis e Ulva lactuca apresentaram os maiores valores de fotossíntese máxima. Foram observadas diferenças no conteúdo de clorofila a entre as espécies de macroalgas estudadas, sendo que os valores variaram de 0,20 ± 0,01 mg/g massa seca (Gigartina skottsbergii) a 6,82 ± 0,46 mg/g massa seca (Spatoglossum schroederi). Também houve grande variação no conteúdo de lipídeos, carboidratos e proteínas, sendo que os maiores valores foram encontrados em D. menstrualis (98,8 + 4,9 mg/g massa seca de lipídeos), Gracilaria mammillaris, Laurencia dendroidea e Plocamium cartilagineum (742,0 ± 31,9, 675,3 ± 11,0 e 660,2 ± 27,2 mg/g massa seca de carboidratos, respectivamente) e Palmaria decipiens e Aglaothamnion uruguayense (21,7 ± 1,7 e 18,0 ± 0,4 mg/g massa seca de proteínas, respectivamente). Houve grande variação na concentração e no perfil de ácidos graxos das espécies estudadas, sendo que D. menstrualis e S. schroederi foram as espécies que apresentaram os maiores valores. Além disso, D. menstrualis exibiu a maior proporção de ácidos graxos monoinsaturados. A partir dos resultados obtidos com as algas coletadas em campo, concluímos que D. menstrualis foi a espécie que apresentou as melhores características para ser utilizada como fonte para produção de biodiesel, devido a sua alta taxa fotossintetizante, alto teor de lipídeos e ácidos graxos e alto teor de ácidos graxos monoinsaturados. Dessa forma, D. menstrualis foi utilizada na segunda etapa do trabalho, sendo estabelecido o seu cultivo em laboratório, com uma taxa de crescimento (TC) de 11,1 % d-1. Foram realizados experimentos para avaliar os efeitos do aumento da concentração de dióxido de carbono (CO2), em condições de limitação e saturação de nitrogênio (na forma de nitrato, NO3-), sobre a TC, a fotossíntese, a atividade das enzimas nitrato redutase (NR), Anidrase Carbonica (AC) e Rubisco e sobre a composição bioquímica de D. menstrualis cultivada em biorreatores e sobre a captação do CO2 por D. menstrualis cultivada em laboratório. A TC, o conteúdo de proteínas e de N total no tecido de D. menstrualis foram maiores nos tratamentos contendo NO3-, independente da adição de CO2. Entretanto, houve um aumento nos valores de fotossíntese máxima, na atividade da Rubisco e NR, e no teor de carboidratos e lipídeos totais quando D. menstrualis foi cultivada em meio com adição de CO2, com saturação de NO3-. Houve pouca variação na atividade da AC entre os diferentes tratamentos testados. O perfil de ácidos graxos de D. menstrualis cultivada nos biorreatores foi caracterizado por um alto conteúdo de ácidos graxos poliinsaturados, com destaque para os omegas-3. Não houve diferença significativa na taxa de remoção de CO2 entre os tratamentos com e sem adição NO3-. A remoção de CO2 nos meios com e sem adição de CO2 foi alta, variando de 71,5% a 34,8%, respectivamente. Os resultados evidenciam que quando essa espécie foi cultivada em biorreatores, houve um aumento no seu teor de ácidos graxos poliinsaturados e ω-3, o que a torna mais interessante para ser utilizada como nutracêutico do que como matéria-prima para a produção de biodiesel. Apesar disso, a sua aplicação como fonte de biodiesel não deve ser desconsiderada, uma vez que alterações nas condições de cultivo acarretam em modificações no perfil de ácidos graxos. Com base nos resultados obtidos, as perspectivas para a produção de biodiesel a partir de macroalgas marinhas deverão contemplar estudos para encontrar as melhores condições de cultivo para que ocorra o aumento na biossíntese de ácidos graxos monoinsaturados. The Biotehcnological potential, with biodiesel producing emphasis, on 25 species of marine benthic algae from the phylum Rhodophyta, Chlorophyta and Heterokontophyta collected along the Brazilian coast, were evaluated assessing their biochemical composition and their photosynthetic rate. Studies have also been performed with 6 seaweed species collected in Admiralty Bay, Antarctic Peninsula, to compare the results presented by these organisms inhabiting an environment of extreme and adverse conditions. For biochemical analysis, pigments (chlorophyll a, for all groups of macroalgae, and phycobiliproteins, allophycocyanin, phycocyanin and phycoerythrin, for the red algae), total soluble protein, total soluble carbohydrates and total lipids and fatty acids were quantified. The species Dictyota menstrualis and Ulva lactuca showed the highest values of maximum photosynthesis. There were differences in chlorophyll a content between the seaweeds studied, and the values ranged from 0.20 ± 0.01 mg / g dry mass (Gigartina skottsbergii) to 6.82 ± 0.46 mg / g dry weight (Spatoglossum schroederi). There was also wide variation in the content of lipids, carbohydrates and proteins, and the highest values were found in the species Dictyota menstrualis (98.8 ± 4.9 mg / g dry weight of lipids), Gracilaria mammillaris, Laurencia dendroidea and Plocamium cartilagineum (742, O ± 31.9, 675.3 ± 11.0 and 660.2 ± 27.2 mg / g dry weight of carbohydrates, respectively) and Palmaria decipiens and Aglaothamnion uruguayense (21.7 ± 1.7 and 18.0 ± 0, 4 mg / g dry weight of proteins, respectively). There was a wide variation on fatty acids contents and profile of the species studied; D. menstrualis and Spatoglossum schroederi showed the highest lipids values. In addition, D. menstrualis exhibited the highest proportion of monounsaturated fatty acids. From the results obtained with algae collected in the field, D. menstrualis is the species with the best characteristics to be used as a source for biodiesel production due to their high photosynthetic rate, high content of lipids and fatty acids and a high content of monounsaturated fatty acids. Thus, D. menstrualis was used in the second stage of this study, being established it\'s cultivation in the laboratory, with a growth rate (GR) of 11.1% d-1. Experiments to evaluate the effect of increasing carbon dioxide (CO2) concentration, under nitrogen (NO3-) limiting and saturation conditions, on the GR, photosynthesis, the activity of nitrate reductase (NR), carbonic anhydrase (CA) and Rubisco and on the biochemical composition of D. menstrualis grown in bioreactors and on the CO2 capture by D. menstrualis grown in the laboratory were performed. The GR, protein content and N content in the tissue of D. menstrualis were higher in treatments containing NO3-, regardless of the addition of CO2. However, there was an increase in the values of maximum photosynthesis, of Rubisco and NR activity, and of total soluble carbohydrates and total lipids when D. menstrualis was grown in medium with addition of CO2, with NO3- saturation. There was little variation in the AC activity among different treatments. The fatty acid profile of D. menstrualis cultivated in bioreactors was characterized by a high content of polyunsaturated fatty acids, especially the omegas-3. There was no significant difference in the rate of CO2 removal between treatments with and without NO3-. CO2 removal in medium with and without addition of CO2 was high, ranging from 71.5% to 34.8%, respectively. The results show that when this species was cultivated in bioreactors, there was an increase in its content of polyunsaturated fatty acids and ω-3, which makes it interesting for use as a nutraceutical than as raw material for biodiesel production. Nevertheless, its application as a source of biodiesel can not be disregarded, since changes in culture conditions lead to changes in fatty acid profile. Based on these results, the prospects for the production of biodiesel from marine macroalgae should include studies to find the best growing conditions to occur the increase in the monounsaturated fatty acids biosynthesis.

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.

Renewable energy has attracted significant interest in recent years as a result of sustainability, environmental impact, and socio-economic considerations. Given existing technological knowledge and based on projections relating to biofuels derived from microalgae, microalgal feedstock is considered to be one of the most important renewable energy sources potentially available for industrial production. Therefore, this review examines microalgal bioethanol technology, which converts biomass from microalgae to fuel, the chemical processes involved, and possible ways of increasing the bioethanol yield, such as abiotic factors and genetic manipulation of fermenting organisms.

To investigate whether the dorsal periaqueductal grey (DPAG) might be involved in the anxiogenic effect of intracerebroventricular (i.c.v.) administered corticotropin-releasing hormone (CRH), rats (n = 6-13) received microinjections into the DPAG of CRH (1 or 2 microg) or saline and were tested on the elevated plus maze. The drug caused a dose-dependent decrease in plus maze exploration (percentage of entries into open arms: saline 31.9 +/- 8.6, CRH 1 microg 19.2 +/- 4.0, CRH 2 microg 6.9 +/- 3.7; p < 0.01, ANOVA). In a second experiment the anxiogenic effect of intra-DPAG CRH (2 microg) was prevented by previous microinjection of alpha-helical-CRH(9-41) (0.5 microg), a CRH antagonist (percentage of entries into open arms: saline + CRH 20.3 +/- 3.7, alpha-helical-CRH(9-41) + CRH 45.7 +/- 1.6). These results suggest that the DPAG may be a site of the anxiogenic effect of i.c.v. injected CRH.

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

Corticotropin-releasing hormone (CRH) is anxiogenic when microinjected into the dorsal periaqueductal gray (DPAG). Microinjection of alpha-helical-CRH9-41 (0.5 microgram), a CRH receptor antagonist, however, failed to change anxiety levels. The objective of this study was to verify if this compound has any effect in the anxiogenic behavior of rats submitted to 4 hr of restraint stress 24 hr before the test in an elevated plus maze. Results showed that stressed rats had a decreased exploration of open arms without changing the number of enclosed arm entries. The stress effect was reversed by intra-DPAG injection of alpha-helical-CRH9-41 (0.5 microgram). These results suggest that the anxiogenic behavior of rats previously stressed by forced immobilization might involve facilitation of CRH-mediated neurotransmission in the DPAG.

A enzima nitrato redutase (NR) catalisa a redução do nitrato a nitrito e controla a taxa de assimilação do nitrato. O ensaio in vitro da nitrato redutase foi otimizado para a linhagem selvagem (marrom, MA) e para a linhagem deficiente em ficoeritrina (verde-clara, VC) de Hypnea musciformis. As duas linhagens foram cultivadas em temperatura de 23 ± 2°C, fotoperíodo de 14 horas, irradiância de 60-90µmol fótons m-2s-1, e meio composto por água do mar esterilizada (30ups) enriquecida com a solução de von Stosch na concentração de 50% (VSES/2). As condições ótimas de ensaio para ambas as linhagens foram: 40µM de NADH; 10min de incubação do extrato bruto (EB) e 100µL de EB. A atividade ótima da NR ocorreu em 4 e 2mM de nitrato para a linhagem VC e MA, respectivamente. As linhagens VC e MA apresentaram, respectivamente, constante aparente de Michaelis-Menten (K M) para NADH de 0,2068 e 0,0837 µM, e K M para nitrato de 0,0492 e 0,0294mM. Os resultados indicam que a NR da linhagem MA tem maior afinidade pelo substrato do que a NR da linhagem VC de H. musciformis. Os experimentos para avaliar os efeitos da disponibilidade de nitrato (5 a 105µM) e nitrato e fosfato (0,5 a 25,5µM, com a relação N:P de 4:1) mostraram que a atividade da NR das linhagens VC e MA não aumentou com a adição de nitrato no meio, o que pode estar relacionado com o estado nutricional dessas algas. A atividade da NR foi maior nos tratamentos com adição de fosfato do que naqueles com adição de apenas nitrato, indicando que esse nutriente é importante para os processos metabólicos relacionados a atividade da NR. The enzyme nitrate reductase (NR) catalyzes the reduction of nitrate to nitrite and controls the rate of nitrate assimilation. The in vitro assay of NR was optimized for the wild strain (brown, MA), and the phycoerythrin-deficient strain (light-green, VC) of Hypnea musciformis. Both strains were cultured at temperature of 23 ± 2°C, photoperiod of 14h, irradiance of 60-90 µmol photons m-2s-1, with medium composed by sterilized seawater (salinity 30 psu) with 50% von Stosch's enrichment solution (VSES/2). The optimal conditions for in vitro assay of NR were: 40µM of NADH; 10min of incubation of crude extracts (EB), and 100µL of EB to both strains. Optimal activity of NR occurred at 4 and 2mM of nitrate to the VC and MA strains, respectively. The VC and MA strains showed, respectively, Michaelis-Menten constants (K M) for NADH of 0.2068 and 0.0837µM, and K M for nitrate of 0.0492 and 0.0294mM. The results indicate that the NR of MA strain has higher affinity by the substrate than the NR of VC strain of H. musciformis. Experiments on the effects of availabilities of nitrate (5 to 105µM) and nitrate and phosphate (0.5 to 25.5µM, with a N:P relation of 4:1) showed that NR activity of VC and MA strain did not increase with the addition of nitrate to the medium, what can be related with their nutritional state. The NR activity was higher in treatments with phosphate addition than those with only nitrate addition, indicating that this nutrient is important to metabolic processes related to the NR activity.

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.

The objective of this study was to investigate possible motor effects of NG-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthase. Acute administration of L-NOARG (5-80 mg kg-1, i.p.) induced catalepsy in a dose-dependent manner in male albino-Swiss mice. The drug had an additive effect with haloperidol (0.125-0.5 mg kg-1, i.p.). The acute effect of L-NOARG (40 mg kg-1, i.p.) was attenuated by previous treatment with L-arginine (300 mg kg-1, i.p.). Sub-chronic treatment with L-NOARG (40 mg kg-1, i.p., twice a day for 4 days) was also able to attenuate the cataleptic effect of acute drug administration (40 mg kg-1, i.p.). These results show that acute systemic injections of L-NOARG induce significant motor effects.