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Vitor Vasconcelos - One of the best experts on this subject based on the ideXlab platform.
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Developing New Marine Antifouling Surfaces: Learning from Single-Strain Laboratory Tests
Coatings, 2021Co-Authors: Sara I. Faria, Vitor Vasconcelos, Luciana Gomes, Rita Teixeira-santos, João Paulo Saraiva Morais, Filipe MergulhãoAbstract:The development of antifouling (AF) technology for marine environments is an area of intense research given the severe economic and ecological effects of marine biofouling. Preliminary data from in vitro assays is frequently used to screen the performance of AF coatings. It is intuitive that microbial composition plays a major role in surface colonization. The rationale behind this study is to investigate whether using a mixed population for the in vitro tests yields substantially different results than using single strains during initial screening. A polymeric coating was tested against single- and dual-species cultures of two common microfouler organisms for 49 days. A bacterium (Pseudoaltermonas tunicata) and a cyanobacterium (Cyanobium sp. LEGE 10375) were used in this study. Linear regression analysis revealed that Cyanobium sp. biofilms were significantly associated with a higher number of cells, wet weight, thickness, and biovolume compared to dual-species biofilms. P. tunicata alone had a biofilm growth kinetics similar to dual-species biofilms, although the P. tunicata–Cyanobium sp. mixture developed less dense and thinner biofilms compared to both single-species biofilms. Cyanobium sp. LEGE 10375 biofilms provided the worst-case scenario, i.e., the conditions that caused higher biofilm amounts on the surface material under test. Therefore, it is likely that assessing the AF performance of new coatings using the most stringent conditions may yield more robust results than using a mixed population, as competition between microfouler organisms may reduce the biofilm formation capacity of the consortium.
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Factorial optimization of upstream process for Cyanobium sp. pigments production
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, Daniel Salvaterra, Helena M. Amaro, Graciliana Lopes, Isabel Sousa-pinto, A. Catarina GuedesAbstract:Cyanobacteria-based pigments, such as carotenoids and phycobiliproteins, have emerged in the last few years as products with great economical interest. However, only the production of a few strains has been optimized for large-scale productions. As photosynthetic components, pigments have their synthesis modulated by abiotic factors, such as pH, temperature and salinity, which can lead to a huge impact on cyanobacteria production. This work aimed the optimization of biomass and pigments production by Cyanobium sp. LEGE 06113, using a factorial Box-Behnken design for three abiotic factors—temperature (20–30 °C), pH (6.0–9.0) and salinity (NaCl, 10–30 g L−1). Biomass, photosynthetic activity, carotenoid and phycobiliprotein productivity and antioxidant capacity of acetonic and aqueous extracts were measured over time and plotted into quadratic models. Results revealed that temperature and pH had a more significant impact than salinity on Cyanobium sp. metabolism and it was possible to determine a significant quadratic model for all evaluated parameters. According to the factorial modelling, the optimal condition for biomass, carotenoids and phycobiliprotein productivity was obtained at 20 °C, pH 9.0 and 10 g L−1 of NaCl, as subsequently confirmed in experimental trials, with an observed productivity of 127.12 ± 1.30 mgDW Lculture−1 day−1 for biomass; 2.04 ± 0.51 mgcarot Lculture−1 day−1 for total carotenoids; and 4.14 ± 0.71 mgphyco Lculture−1 day−1 for total phycobiliproteins.
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Light quality triggers biochemical modulation of Cyanobium sp.—photobiology as tool for biotechnological optimization
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, A. Catarina Guedes, Julia Vega, José Bonomi-barufi, Roberto Abdala-díaz, Félix L. FigueroaAbstract:Cyanobacteria are able to absorb light over a wide spectral range due to the presence of photoreceptors, making it possible to modulate the production of high-value compounds by inducing specific pathways. In order to evaluate the influence of light quality in cyanobacteria metabolism, Cyanobium sp. was grown in five different light conditions, by using low-pressure sodium vapor lamp (SOX) supplemented with low irradiances of green, red, and blue light and UV radiation compared to a control with only SOX. The effects of light supplementation on biomass productivity, photosynthetic activity, biochemical composition, and total antioxidant capacity were evaluated. No changes in biomass productivity were induced by any light supplements. The supplementation of red light triggered the production of lipids, phycocyanin, carotenoids, and total antioxidant compounds, while supplementation of green light increased the content of carbohydrates and chlorophyll a . Thus, supplementation of blue light and UV radiation showed little or no improvements to the culture, whereas under UV radiation the photosynthetic activity was reduced. Overall, Cyanobium sp. is a promising strain, mainly due to its accessibility to metabolism photoregulation as to produce various bioactive compounds.
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Exploitation of Filamentous and Picoplanktonic Cyanobacteria for Cosmetic Applications: Potential to Improve Skin Structure and Preserve Dermal Matrix Components.
Marine drugs, 2020Co-Authors: Janaína Morone, Graciliana Lopes, Vitor Vasconcelos, Marco Preto, Rosário MartinsAbstract:The use of natural products in skin care formulations gained interest as a concern for modern societies. The undesirable side effects of synthetic compounds, as well as the associated environmental hazards, have driven investigation on photosynthetic organisms as sustainable sources of effective and environmentally friendly ingredients. The use of natural extracts in cosmetics has been highlighted and, along with plants and algae, cyanobacteria have come into focus. Due to their low culture demands, high grow rates and ability to produce a wide variability of bioactive metabolites, cyanobacteria emerged as an economic and sustainable base for the cosmetic industry. In this study, we evaluated the potential of ethanol extracts of picocyanobacteria strains of the genera Cyanobium and Synechocystis and filamentous strains of the genera Nodosilinea, Phormidium and Tychonema for skin applications, with focus in the field of anti-aging. The extracts were analyzed for their pigment profile, phenolic content, antioxidant potential, cytotoxicity against keratinocytes (HaCat), fibroblasts (3T3L1), endothelial cells (hCMEC/D3) and capacity to inhibit hyaluronidase (HAase). The total carotenoid content ranged from 118.69 to 383.89 μg g−1 of dry biomass, and the total phenolic content from 1.07 to 2.45 mg GAE g−1. Identified carotenoids consisted of zeaxanthin, lutein, canthaxanthin, echinenone and β-carotene, with zeaxanthin and lutein being the most representative (49.82 and 79.08 μg g−1, respectively). The highest antioxidant potential was found for Phormidium sp. LEGE 05292 and Tychonema sp. LEGE 07196 for superoxide anion radical (O2•−) scavenging (IC50 of 822.70 and 924 μg mL−1, respectively). Low or no cytotoxicity were registered. Regarding HAase inhibition, Tychonema sp. LEGE 07196 and Cyanobium sp. LEGE 07175 showed the best IC50 (182.74 and 208.36 μg mL−1, respectively). In addition, an increase in fibroblast proliferation was registered with these same strains. From this work, the ethanol extracts of the species Tychonema sp. and Cyanobium sp. are particularly interesting for their potential application in anti-aging formulations, once they stimulated fibroblast proliferation and inhibit hyaluronic acid digestion.
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Bioactive potential of Cyanobium sp. pigment-rich extracts
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, Daniel Salvaterra, Helena M. Amaro, Graciliana Lopes, Isabel Sousa-pinto, A. Catarina GuedesAbstract:Cyanobacteria are able to synthesize high-value compounds, such as pigments, known for their bioactivities and several industrial uses. One of the key points for the extraction of pigments is solvent selection. Solvent interferes on pigments concentration, thus affecting the bioactive potential of the extracts. In this work, using frozen-dried biomass of Cyanobium sp. LEGE 06113, organic and aqueous pigment-rich extracts were obtained by a classic extraction methodology using four solvents — acetone (A), ethyl acetate (EA), ethanol (E) and water (W). In order to increase the efficiency of extraction from the cyanobacterium biomass, successive extractions were performed by using water after organic extraction (A-W, E-W, EA-W) and acetone after the aqueous extraction (W-A). Extraction yield and profile of carotenoids, phycobiliproteins, and phenolic compounds were quantified. The bioactive potential of Cyanobium sp. extracts was assessed in terms of antioxidant capacity (ABTS•+, •NO, O2•− scavenging), anti-inflammatory capacity (COX inhibition), and cytotoxicity (HepG2). W-A showed the higher antioxidant capacity and higher content in carotenoids. E-W showed the highest content in phycobiliproteins and great antioxidant capacity. In terms of anti-inflammatory capacity, 100 μgE mL−1 of E-W extract exhibited capacity to inhibit both COX-1 and COX-2 enzymes. Finally, in what concerns the cytotoxic evaluation, E, W, A-W, E-W, and EA-W revealed to have no cytotoxic effects in concentrations up to 750 μgE mL−1. Overall, this work constitutes a valid contribution for the valorisation of Cyanobium sp. pigment-rich extracts for biotechnological applications.
Rosário Martins - One of the best experts on this subject based on the ideXlab platform.
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Exploitation of Filamentous and Picoplanktonic Cyanobacteria for Cosmetic Applications: Potential to Improve Skin Structure and Preserve Dermal Matrix Components.
Marine drugs, 2020Co-Authors: Janaína Morone, Graciliana Lopes, Vitor Vasconcelos, Marco Preto, Rosário MartinsAbstract:The use of natural products in skin care formulations gained interest as a concern for modern societies. The undesirable side effects of synthetic compounds, as well as the associated environmental hazards, have driven investigation on photosynthetic organisms as sustainable sources of effective and environmentally friendly ingredients. The use of natural extracts in cosmetics has been highlighted and, along with plants and algae, cyanobacteria have come into focus. Due to their low culture demands, high grow rates and ability to produce a wide variability of bioactive metabolites, cyanobacteria emerged as an economic and sustainable base for the cosmetic industry. In this study, we evaluated the potential of ethanol extracts of picocyanobacteria strains of the genera Cyanobium and Synechocystis and filamentous strains of the genera Nodosilinea, Phormidium and Tychonema for skin applications, with focus in the field of anti-aging. The extracts were analyzed for their pigment profile, phenolic content, antioxidant potential, cytotoxicity against keratinocytes (HaCat), fibroblasts (3T3L1), endothelial cells (hCMEC/D3) and capacity to inhibit hyaluronidase (HAase). The total carotenoid content ranged from 118.69 to 383.89 μg g−1 of dry biomass, and the total phenolic content from 1.07 to 2.45 mg GAE g−1. Identified carotenoids consisted of zeaxanthin, lutein, canthaxanthin, echinenone and β-carotene, with zeaxanthin and lutein being the most representative (49.82 and 79.08 μg g−1, respectively). The highest antioxidant potential was found for Phormidium sp. LEGE 05292 and Tychonema sp. LEGE 07196 for superoxide anion radical (O2•−) scavenging (IC50 of 822.70 and 924 μg mL−1, respectively). Low or no cytotoxicity were registered. Regarding HAase inhibition, Tychonema sp. LEGE 07196 and Cyanobium sp. LEGE 07175 showed the best IC50 (182.74 and 208.36 μg mL−1, respectively). In addition, an increase in fibroblast proliferation was registered with these same strains. From this work, the ethanol extracts of the species Tychonema sp. and Cyanobium sp. are particularly interesting for their potential application in anti-aging formulations, once they stimulated fibroblast proliferation and inhibit hyaluronic acid digestion.
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Norhierridin B, a New Hierridin B-Based Hydroquinone with Improved Antiproliferative Activity.
Molecules (Basel Switzerland), 2020Co-Authors: Pedro Brandão, Rosário Martins, Vitor Vasconcelos, Pedro N. Leão, Ivo E. Sampaio-dias, Joana Moreira, Joana Almeida, Nair Nazareth, Madalena Pinto, Lucília SaraivaAbstract:Hierridin B (6), a methylated hydroquinone isolated from the marine picocyanobacterium Cyanobium sp. LEGE 06113, moderately inhibited the growth of colon adenocarcinoma HT-29 cells. Aiming to improve the potential antitumor activity of this natural product, the demethylated analogue, norhierridin B (10), as well as its structurally-related quinone (9), were synthesized and evaluated for their growth inhibitory effect on a panel of human tumor cell lines, including the triple-negative breast cancer (TNBC) cells MDA-MB-231, SKBR3, and MDA-MB-468. Norhierridin B (10) showed a potent growth inhibitory effect on all cancer cell lines. Moreover, the growth inhibitory effect of compound 10 on MDA-MB-231 cells was associated with cell cycle arrest and apoptosis. Norhierridin B (10) interfered with several p53 transcriptional targets, increasing p21, Bax, and MDM2, while decreasing Bcl-2 protein levels, which suggested the potential activation of a p53 pathway. Altogether, these results evidenced a great improvement of the antitumor activity of hydroquinone 10 when compared to 6 and its structurally-related quinone (9). Notably, hydroquinone 10 displayed a prominent growth inhibitory activity against TNBC cells, which are characterized by high therapeutic resistance.
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Structure, Synthesis of Hierridin C and Discovery of Prevalent Alkylresorcinol Biosynthesis in Picocyanobacteria
2018Co-Authors: Margarida Costa, Rosário Martins, Ivo E. Sampaio-dias, Raquel Castelo-branco, Hugo Scharfenstein, Artur Silva, Roberta Rezende De Castro, Maria Paula Cruz Schneider, Maria João Araújo, Valentina F. DominguesAbstract:Small, single-celled planktonic cyanobacteria are ubiquitous in the world’s oceans yet tend not to to be perceived as biosynthetically-prolific organisms. Here we report the isolation and structure elucidation of hierridin C, an antiplasmodial halogenated alkylresorcinol produced in very low amounts by the picocyanobacterium <i>Cyanobium</i>sp. LEGE 06113. We describe a simple, straightforward synthetic route to the scarcely-produced hierridins that relies on a key, highly regioselective halogenation step. In addition, we show that these compounds originate from a type III PKS pathway and that similar biosynthetic gene clusters are found in a variety of bacterial genomes, most notably those of the globally-distributed picocyanobacteria genera <i>Prochlorococcus</i>, <i>Cyanobium</i>and <i>Synechococcus</i>.
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Hierridin B Isolated from a Marine Cyanobacterium Alters VDAC1, Mitochondrial Activity, and Cell Cycle Genes on HT-29 Colon Adenocarcinoma Cells.
Marine drugs, 2016Co-Authors: Sara Freitas, Rosário Martins, Margarida Costa, Vitor Vasconcelos, Pedro N. Leão, Rui Vitorino, Ralph UrbatzkaAbstract:Background: Hierridin B was isolated from a marine cyanobacterium Cyanobium sp. strain and induced cytotoxicity selectively in HT-29 adenocarcinoma cells. The underlying molecular mechanism was not yet elucidated. Methods: HT-29 cells were exposed to the IC50 concentration of hierridin B (100.2 μM) for 48 h. Non-targeted proteomics was performed using 2D gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The mRNA expression of apoptotic and cell cycle genes were analyzed by real-time PCR. Automated quantification of 160 cytoplasm and mitochondrial parameter was done by fluorescence microscopy using CellProfiler software. Results: Proteomics identified 21 significant different proteins, which belonged to protein folding/synthesis and cell structure amongst others. Increase of VDAC1 protein responsible for formation of mitochondrial channels was confirmed by mRNA expression. A 10-fold decrease of cytoskeleton proteins (STMN1, TBCA) provided a link to alterations of the cell cycle. CCNB1 and CCNE mRNA were decreased two-fold, and P21CIP increased 10-fold, indicative of cell cycle arrest. Morphological analysis of mitochondrial parameter confirmed a reduced mitochondrial activity. Conclusion: Hierridin B is a potential anticancer compound that targets mitochondrial activity and function.
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Insights into the potential of picoplanktonic marine cyanobacteria strains for cancer therapies - Cytotoxic mechanisms against the RKO colon cancer cell line
Toxicon : official journal of the International Society on Toxinology, 2016Co-Authors: Sara Freitas, Rosário Martins, Alexandre Campos, Joana Azevedo, Hugo Osório, Margarida Costa, Piedade Barros, Vitor Vasconcelos, Ralph UrbatzkaAbstract:Abstract Purpose In this work, we analysed the potential of picoplanktonic marine cyanobacteria strains as a source of anticancer compounds by elucidating the cytotoxic mechanisms of an ethyl acetate fraction of Cyanobium sp. (LEGE06113) and the Synechocystis salina (LEGE06155) on the RKO colon adenocarcinoma cell line. Methods Cytotoxicity was analysed by MTT. Effects on cells were evaluated by mRNA expression of cell cycle and apoptotic genes, flow cytometry (cell cycle), qualitative and quantitative fluorescence microscopy (apoptosis), and quantitative proteomics. Results IC50 values were 27.01 and 8.03 μg/ml for Cyanobium sp., and 37.71 and 17.17 μg/ml for Synechocystis salina, after 24 h and 48 h, respectively. Exposure to the Cyanobium sp. fraction increased 2.5 fold BCL-2 mRNA expression (p Conclusion Since induction of cytotoxicity is a very broad parameter, the study demonstrates the potential of picocyanobacteria to produce bioactive compounds that target cancer cells via different molecular mechanisms.
A. Catarina Guedes - One of the best experts on this subject based on the ideXlab platform.
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Factorial optimization of upstream process for Cyanobium sp. pigments production
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, Daniel Salvaterra, Helena M. Amaro, Graciliana Lopes, Isabel Sousa-pinto, A. Catarina GuedesAbstract:Cyanobacteria-based pigments, such as carotenoids and phycobiliproteins, have emerged in the last few years as products with great economical interest. However, only the production of a few strains has been optimized for large-scale productions. As photosynthetic components, pigments have their synthesis modulated by abiotic factors, such as pH, temperature and salinity, which can lead to a huge impact on cyanobacteria production. This work aimed the optimization of biomass and pigments production by Cyanobium sp. LEGE 06113, using a factorial Box-Behnken design for three abiotic factors—temperature (20–30 °C), pH (6.0–9.0) and salinity (NaCl, 10–30 g L−1). Biomass, photosynthetic activity, carotenoid and phycobiliprotein productivity and antioxidant capacity of acetonic and aqueous extracts were measured over time and plotted into quadratic models. Results revealed that temperature and pH had a more significant impact than salinity on Cyanobium sp. metabolism and it was possible to determine a significant quadratic model for all evaluated parameters. According to the factorial modelling, the optimal condition for biomass, carotenoids and phycobiliprotein productivity was obtained at 20 °C, pH 9.0 and 10 g L−1 of NaCl, as subsequently confirmed in experimental trials, with an observed productivity of 127.12 ± 1.30 mgDW Lculture−1 day−1 for biomass; 2.04 ± 0.51 mgcarot Lculture−1 day−1 for total carotenoids; and 4.14 ± 0.71 mgphyco Lculture−1 day−1 for total phycobiliproteins.
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Light quality triggers biochemical modulation of Cyanobium sp.—photobiology as tool for biotechnological optimization
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, A. Catarina Guedes, Julia Vega, José Bonomi-barufi, Roberto Abdala-díaz, Félix L. FigueroaAbstract:Cyanobacteria are able to absorb light over a wide spectral range due to the presence of photoreceptors, making it possible to modulate the production of high-value compounds by inducing specific pathways. In order to evaluate the influence of light quality in cyanobacteria metabolism, Cyanobium sp. was grown in five different light conditions, by using low-pressure sodium vapor lamp (SOX) supplemented with low irradiances of green, red, and blue light and UV radiation compared to a control with only SOX. The effects of light supplementation on biomass productivity, photosynthetic activity, biochemical composition, and total antioxidant capacity were evaluated. No changes in biomass productivity were induced by any light supplements. The supplementation of red light triggered the production of lipids, phycocyanin, carotenoids, and total antioxidant compounds, while supplementation of green light increased the content of carbohydrates and chlorophyll a . Thus, supplementation of blue light and UV radiation showed little or no improvements to the culture, whereas under UV radiation the photosynthetic activity was reduced. Overall, Cyanobium sp. is a promising strain, mainly due to its accessibility to metabolism photoregulation as to produce various bioactive compounds.
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Bioactive potential of Cyanobium sp. pigment-rich extracts
Journal of Applied Phycology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, Daniel Salvaterra, Helena M. Amaro, Graciliana Lopes, Isabel Sousa-pinto, A. Catarina GuedesAbstract:Cyanobacteria are able to synthesize high-value compounds, such as pigments, known for their bioactivities and several industrial uses. One of the key points for the extraction of pigments is solvent selection. Solvent interferes on pigments concentration, thus affecting the bioactive potential of the extracts. In this work, using frozen-dried biomass of Cyanobium sp. LEGE 06113, organic and aqueous pigment-rich extracts were obtained by a classic extraction methodology using four solvents — acetone (A), ethyl acetate (EA), ethanol (E) and water (W). In order to increase the efficiency of extraction from the cyanobacterium biomass, successive extractions were performed by using water after organic extraction (A-W, E-W, EA-W) and acetone after the aqueous extraction (W-A). Extraction yield and profile of carotenoids, phycobiliproteins, and phenolic compounds were quantified. The bioactive potential of Cyanobium sp. extracts was assessed in terms of antioxidant capacity (ABTS•+, •NO, O2•− scavenging), anti-inflammatory capacity (COX inhibition), and cytotoxicity (HepG2). W-A showed the higher antioxidant capacity and higher content in carotenoids. E-W showed the highest content in phycobiliproteins and great antioxidant capacity. In terms of anti-inflammatory capacity, 100 μgE mL−1 of E-W extract exhibited capacity to inhibit both COX-1 and COX-2 enzymes. Finally, in what concerns the cytotoxic evaluation, E, W, A-W, E-W, and EA-W revealed to have no cytotoxic effects in concentrations up to 750 μgE mL−1. Overall, this work constitutes a valid contribution for the valorisation of Cyanobium sp. pigment-rich extracts for biotechnological applications.
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Light regulating metabolic responses of Cyanobium sp. (Cyanobacteria)
Fundamental and Applied Limnology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, A. Catarina Guedes, José Bonomi Barufi, Julia Vega, Roberto Teofilo Abdala-diaz, Félix L. FigueroaAbstract:A PhD fellowship (reference SFRH/BD/136767/2018) for author F.P. was granted by Fundacao para a Ciencia e Tecnologia (FCT, Portugal) under the auspices of Programa Operacional Capital Humano (POCH), supported by the European Social Fund and Portuguese funds (MECTES); a grant of the Carolina Foundation was given to author J.B.B.. This work was financially co- supported by the COST Action ES1408 European network for algal-bioproducts (EUALGAE); by the ZEBRALGRE (PTDC/ CVT-WEL/5207/2014), founded by national funds through FCT supported by COMPETE 2020: POCI-01-0145-FEDER-016797; by the strategic founding from FCT (UIDB/04423/2020 and UIDP/04423/2020) and the Atlantic Interreg Project – Enhance MicroAlgae – High added-value industrial opportunities for microalgae in the Atlantic Area (EAPA_338/2016). We also acknowledge the Junta de Andalucia for financing the RNM295 research group at the University of Malaga.
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White and red LEDs as two-phase batch for cyanobacterial pigments production
Bioresource technology, 2020Co-Authors: Fernando Pagels, Vitor Vasconcelos, Graciliana Lopes, A. Catarina GuedesAbstract:Abstract Carotenoids and phycobiliproteins have a high economic value, due to their wide range of biological and industrial applications. The implementation of strategies to increase their production, such as the application of two-phase light cultivation systems, can stimulate pigments production, increasing economic turnover. In this sense, Cyanobium sp. was grown in seven different two-phase white/red cultivation arrangements, varying the time of each light from 0 to 21 days. Biomass, photosynthetic activity, pigments profile and antioxidant capacity were measured along time. Red light increased photosynthetic activity and pigments content (ca. 1.8-fold), and the use of a two-phase cultivation system generally raised bioactivity and production of phytochemicals. Among the studied, the optimal cultivation condition was found with 10 days of white followed by 4 days of red light. The optimized growth led to a productivity of 137.4 ± 0.8 mg L−1 d−1 of biomass, 17.0 ± 0.2 mg L−1 d−1 of total phycobiliproteins and 4.5 ± 0.2 mg L−1 d−1 of carotenoids.
Margarida Costa - One of the best experts on this subject based on the ideXlab platform.
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Structure of Hierridin C, Synthesis of Hierridins B and C, and Evidence for Prevalent Alkylresorcinol Biosynthesis in Picocyanobacteria
2019Co-Authors: Margarida Costa, Ivo E. Sampaio-dias, Raquel Castelo-branco, Hugo Scharfenstein, Roberta Rezende De Castro, Artur Silva, Maria Paula C. Schneider, Maria João Araújo, Rosário Martins, Valentina F. DominguesAbstract:Small, single-celled planktonic cyanobacteria are ubiquitous in the world’s oceans yet tend not to be perceived as secondary metabolite-rich organisms. Here we report the isolation and structure elucidation of hierridin C, a minor metabolite obtained from the cultured picocyanobacterium Cyanobium sp. LEGE 06113. We describe a simple, straightforward synthetic route to the scarcely produced hierridins that relies on a key regioselective halogenation step. In addition, we show that these compounds originate from a type III PKS pathway and that similar biosynthetic gene clusters are found in a variety of bacterial genomes, most notably those of the globally distributed picocyanobacteria genera Prochlorococcus, Cyanobium and Synechococcus
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Structure, Synthesis of Hierridin C and Discovery of Prevalent Alkylresorcinol Biosynthesis in Picocyanobacteria
2018Co-Authors: Margarida Costa, Rosário Martins, Ivo E. Sampaio-dias, Raquel Castelo-branco, Hugo Scharfenstein, Artur Silva, Roberta Rezende De Castro, Maria Paula Cruz Schneider, Maria João Araújo, Valentina F. DominguesAbstract:Small, single-celled planktonic cyanobacteria are ubiquitous in the world’s oceans yet tend not to to be perceived as biosynthetically-prolific organisms. Here we report the isolation and structure elucidation of hierridin C, an antiplasmodial halogenated alkylresorcinol produced in very low amounts by the picocyanobacterium <i>Cyanobium</i>sp. LEGE 06113. We describe a simple, straightforward synthetic route to the scarcely-produced hierridins that relies on a key, highly regioselective halogenation step. In addition, we show that these compounds originate from a type III PKS pathway and that similar biosynthetic gene clusters are found in a variety of bacterial genomes, most notably those of the globally-distributed picocyanobacteria genera <i>Prochlorococcus</i>, <i>Cyanobium</i>and <i>Synechococcus</i>.
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Antitumor activity of hierridin B, a cyanobacterial secondary metabolite found in both filamentous and unicellular marine strains. PLoS One 2013
2016Co-Authors: Pedro N. Leão, Margarida Costa, Vitor Ramos, Alban R. Pereira, Valentina F. Domingues, William H. Gerwick, Virgı́nia C. Fern, Vitor M. VasconcelosAbstract:Cyanobacteria are widely recognized as a valuable source of bioactive metabolites. The majority of such compounds have been isolated from so-called complex cyanobacteria, such as filamentous or colonial forms, which usually display a larger number of biosynthetic gene clusters in their genomes, when compared to free-living unicellular forms. Nevertheless, picocyanobacteria are also known to have potential to produce bioactive natural products. Here, we report the isolation of hierridin B from the marine picocyanobacterium Cyanobium sp. LEGE 06113. This compound had previously been isolated from the filamentous epiphytic cyanobacterium Phormidium ectocarpi SAG 60.90, and had been shown to possess antiplasmodial activity. A phylogenetic analysis of the 16S rRNA gene from both strains confirmed that these cyanobacteria derive from different evolutionary lineages. We further investigated the biological activity of hierridin B, and tested its cytotoxicity towards a panel of human cancer cell lines; it showed selective cytotoxicity towards HT-29 colo
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Hierridin B Isolated from a Marine Cyanobacterium Alters VDAC1, Mitochondrial Activity, and Cell Cycle Genes on HT-29 Colon Adenocarcinoma Cells.
Marine drugs, 2016Co-Authors: Sara Freitas, Rosário Martins, Margarida Costa, Vitor Vasconcelos, Pedro N. Leão, Rui Vitorino, Ralph UrbatzkaAbstract:Background: Hierridin B was isolated from a marine cyanobacterium Cyanobium sp. strain and induced cytotoxicity selectively in HT-29 adenocarcinoma cells. The underlying molecular mechanism was not yet elucidated. Methods: HT-29 cells were exposed to the IC50 concentration of hierridin B (100.2 μM) for 48 h. Non-targeted proteomics was performed using 2D gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The mRNA expression of apoptotic and cell cycle genes were analyzed by real-time PCR. Automated quantification of 160 cytoplasm and mitochondrial parameter was done by fluorescence microscopy using CellProfiler software. Results: Proteomics identified 21 significant different proteins, which belonged to protein folding/synthesis and cell structure amongst others. Increase of VDAC1 protein responsible for formation of mitochondrial channels was confirmed by mRNA expression. A 10-fold decrease of cytoskeleton proteins (STMN1, TBCA) provided a link to alterations of the cell cycle. CCNB1 and CCNE mRNA were decreased two-fold, and P21CIP increased 10-fold, indicative of cell cycle arrest. Morphological analysis of mitochondrial parameter confirmed a reduced mitochondrial activity. Conclusion: Hierridin B is a potential anticancer compound that targets mitochondrial activity and function.
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Insights into the potential of picoplanktonic marine cyanobacteria strains for cancer therapies - Cytotoxic mechanisms against the RKO colon cancer cell line
Toxicon : official journal of the International Society on Toxinology, 2016Co-Authors: Sara Freitas, Rosário Martins, Alexandre Campos, Joana Azevedo, Hugo Osório, Margarida Costa, Piedade Barros, Vitor Vasconcelos, Ralph UrbatzkaAbstract:Abstract Purpose In this work, we analysed the potential of picoplanktonic marine cyanobacteria strains as a source of anticancer compounds by elucidating the cytotoxic mechanisms of an ethyl acetate fraction of Cyanobium sp. (LEGE06113) and the Synechocystis salina (LEGE06155) on the RKO colon adenocarcinoma cell line. Methods Cytotoxicity was analysed by MTT. Effects on cells were evaluated by mRNA expression of cell cycle and apoptotic genes, flow cytometry (cell cycle), qualitative and quantitative fluorescence microscopy (apoptosis), and quantitative proteomics. Results IC50 values were 27.01 and 8.03 μg/ml for Cyanobium sp., and 37.71 and 17.17 μg/ml for Synechocystis salina, after 24 h and 48 h, respectively. Exposure to the Cyanobium sp. fraction increased 2.5 fold BCL-2 mRNA expression (p Conclusion Since induction of cytotoxicity is a very broad parameter, the study demonstrates the potential of picocyanobacteria to produce bioactive compounds that target cancer cells via different molecular mechanisms.
Takahiro Yamagishi - One of the best experts on this subject based on the ideXlab platform.
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differential heavy metal sensitivity in seven algal species from the nies culture collection based on delayed fluorescence assays
Phycological Research, 2020Co-Authors: Shuhei Ota, Haruyo Yamaguchi, Faustine Vanel, Shigeshi Fuchida, Hiroshi Koshikawa, Takahiro Yamagishi, Hiroshi Yamamoto, Masanobu KawachiAbstract:Seafloor massive sulfide (SMS) deposits are the target of available metallic resources. The toxic impacts of leachable metals from hydrothermal ore by mining operations in marine environments are a concern. However, ecotoxicological knowledge about marine algae, and particularly open ocean species, is still limited. Here, we evaluated the toxic effects of three leachable metals (i.e. Zn, Cu, and Pb) on seven marine algae, including cyanobacteria and eukaryotes, by a delayed fluorescence method. Cyanobacterial Synechococcus and Cyanobium species were sensitive to Zn and Cu, while eukaryotic algae showed various responses to heavy metal species. The prasinophycean Bathycoccus prasinos NIES‐2670 was sensitive to all metal species; this strain is a potential test strain to detect the leachable metals. A co‐culture experiment showed that the impact on community structure varies depending on leachable metal species. This study demonstrates that surveys across multiple taxonomic groups are necessary to assess the impact of SMS‐mining operations on marine ecosystems as a whole.
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Ecotoxicological Bioassay Using Marine Algae for Deep-Sea Mining
Environmental Issues of Deep-Sea Mining, 2019Co-Authors: Takahiro Yamagishi, Shuhei Ota, Haruyo Yamaguchi, Hiroshi Koshikawa, Hiroshi Yamamoto, Norihisa Tatarazako, Masanobu KawachiAbstract:A new bioassay method using delayed fluorescence (DF) intensity in marine cyanobacterium has been developed. This method offers several advantages for marine environmental risk assessment in deep-sea mining areas: DF-based bioassay uses smaller amounts of a test substance or wastewater and takes less time and space than the standard bioassay method. We selected the marine cyanobacterium Cyanobium sp. (NIES-981) as our test algal species and demonstrated that use of this species was valid in standard growth inhibition testing based on OECD guideline criteria. Standard inhibition tests and shorter testing using DF were performed on NIES-981 by using five chemicals (3,5-DCP, simazine, diflufenican, K2Cr2O7, and CuSO4), and their EC50 and low-toxic-effect values (EC10, EC5, and NOEC) were determined from dose-response curves. On the basis of comparisons of the two dose-response curves and the EC50 values, we concluded that DF intensity was useful as an endpoint for rapid estimation of EC50 in NIES-981. In addition, a delayed fluorescence-based bioassay using Cyanobium sp. NIES-981 was used to evaluate the toxicity of core samples obtained from drill holes at the Izena Hole, Middle Okinawa Trough, East China Sea. The results revealed that unexpected leakage of recovered minerals and mining wastewater from the mining plant could result in heavy metal contamination of the surface water. Moreover, on the basis of the results of microplate-based assay using various marine algae, we suggest using eukaryotic marine algae such as Emiliania huxleyi NIES-1310, Micromonas pusilla NIES-1411, and Bathycoccus prasinos NIES-2670 in addition to Cyanobium sp. NIES-981 for management of seawater quality at deep-sea mining sites because sensitivity to lead in eukaryotic marine algae are more sensitive than cyanobacteria.
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Evaluation of the toxicity of leaches from hydrothermal sulfide deposits by means of a delayed fluorescence-based bioassay with the marine cyanobacterium Cyanobium sp. NIES-981
Ecotoxicology, 2018Co-Authors: Takahiro Yamagishi, Shigeshi Fuchida, Hiroshi Koshikawa, Masanobu Kawachi, Masakazu Katsumata, Yoshifumi Horie, Fumi Mori, Akiko Kitayama, Tatsuo Nozaki, Hidenori KumagaiAbstract:The commercial use of metals such as copper, lead, and zinc has markedly increased in recent years, resulting in increased interest in deep-sea mining of seafloor hydrothermal sulfide deposits. However, the full extent of the impact of deep-sea mining at hydrothermal field deposits on the environment remains unclear. In addition to impacting the deep sea, the leaching of heavy metals from extracted sulfide mineral may also affect the upper ocean zones as the sulfide rock is retrieved from the seafloor. Here, we used a delayed fluorescence-based bioassay using the marine cyanobacterium Cyanobium sp. NIES-981 to evaluate the toxicity of three sulfide core samples obtained from three drill holes at the Izena Hole, middle Okinawa Trough, East China Sea. Leaches from two of the cores contained high concentrations of zinc and lead, and they markedly inhibited delayed fluorescence in Cyanobium sp. NIES-981 compared with control. By examining the toxicity of artificial mixed-metal solutions with metal compositions similar to those of the leaches, we confirmed that this inhibition was a result of high zinc and lead concentrations into the leaches. In addition, we conclude that this delayed fluorescence-based bioassay is a viable method for use by deep-sea mining operations because it is quicker and requires less laboratory space and equipment than the standard assay.
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Rapid ecotoxicological bioassay using delayed fluorescence in the marine cyanobacterium Cyanobium sp. (NIES-981)
Ecotoxicology, 2016Co-Authors: Takahiro Yamagishi, Haruyo Yamaguchi, Hiroshi Koshikawa, Masanobu Kawachi, Yohei Shimura, Masakazu Katsumata, Yoshifumi Horie, Norihisa TatarazakoAbstract:The use of delayed fluorescence intensity as an endpoint for rapid estimation of the effective concentration (EC_x) has been reported as an alternative to standard growth inhibition (at 72 h after exposure) in some algal species including Pseudokirchneriella subcapitata . In marine algae, although an approach of bioassaying using delayed fluorescence measurements has not been performed yet, its development would provide many benefits for marine environmental risk assessment. In this study, we selected marine cyanobacterium Cyanobium sp. (NIES-981) as our test algal species and demonstrated that this species is valid for the standard growth inhibition test based on criteria provide by Organization for Economic Co-operation and Development guidelines. Furthermore, standard inhibition tests and shorter period test using DF were performed in NIES-981 using five chemicals (3,5-DCP, simazine, diflufenican, K_2Cr_2O_7, and CuSO_4), and their EC_50 and low-toxic-effect values (EC_10, EC_5, and NOEC) were determined from two dose-response curves. Based on comparisons of the two dose-response curves and the EC_50 values, we conclude that DF intensity is useful as an endpoint for rapid estimation of EC_50 in NIES-981.
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Complete Genome Sequence of Cyanobium sp. NIES-981, a Marine Strain Potentially Useful for Ecotoxicological Bioassays.
Genome announcements, 2016Co-Authors: Haruyo Yamaguchi, Takahiro Yamagishi, Norihisa Tatarazako, Yohei Shimura, Shigekatsu Suzuki, Masanobu KawachiAbstract:ABSTRACT Cyanobium sp. NIES-981 is a marine cyanobacterium isolated from tidal flat sands in Okinawa, Japan. Here, we report the complete 3.0-Mbp genome sequence of NIES-981, which is composed of a single chromosome, and its annotation. This sequence information may provide a basis for developing an ecotoxicological bioassay using this strain.
