Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.111
Filtrar
1.
Mar Pollut Bull ; 155: 110962, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32469791

RESUMO

The aim of the study was to assess the effect of seaweed cultivation on the coastal environment. We analysed a multitude of environmental parameters using an asymmetrical before after control impact (BACI) design, comparing the seaweed farm (impact) with multiple unaffected locations (controls). The seaweed farm had a significant positive effect on benthic infauna (p<0.05) and was found to attract 17 mobile faunal and 7 other seaweed species, indicating that the farmed crop may provide habitat to mobile faunal species. A light attenuation of approximately 40% at 5m depth was noted at the peak of the seaweed biomass just before harvest. No changes were observed in benthic oxygen flux, dissolved nutrient concentrations, and benthic mobile fauna between farm and control sites. These results show that seaweed aquaculture has limited environmental effects, especially compared to other forms of aquaculture such as fish and bivalve farming.


Assuntos
Kelp , Feófitas , Alga Marinha , Animais , Aquicultura , Meio Ambiente
2.
Sci Total Environ ; 731: 138896, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32408206

RESUMO

The ocean acidification may severely affect macroalgal communities of the shallowest coastal habitats where they play relevant structural and functional roles. In this paper were investigated the physiological traits of two populations of Dictyota dichotoma var. intricata, living at two different pH for several generations to assess the reasons of the algae reduced abundance at current (8.1) compared to low pH (6.7). Besides, through transplant experiments, the two populations were analysed for the stress response and reversibility of physiological performance at different pH. The long-term acclimation to high pCO2/low pH favours an ecotype characterised by low energetic costs, higher photochemical efficiency and more resistance to the oxidative stress, compared to individuals living at current pH. These traits promoted the growth and reproduction of the community living at pH 6.7, favouring a lower macroalgal diversity, but a higher ecological success under ocean acidification. The similar behaviour observed between Dictyota living at pH 6.7 and transplanted thalli from pH 6.7 to 8.1, suggested a high tolerance to pH changes in the short-term. On the contrary, adaptive responses may have favoured molecular adjustments on the long-term, as showed by the significant differences between the wild populations at pH 8.1 and 6.7. The overall data indicate that both plasticity and adaptive mechanisms may be the reasons for the success of the brown seaweeds under future high pCO2/low pH. The plasticity due to photochemistry adjustments is likely involved in the early response to environmental changes. Conversely, modifications in the photosynthetic biochemical machinery suggest that more complex adaptive mechanisms occurred in the current population of Dictyota living at pH 6.7. Further studies on population genetics will reveal if any differentiation is taking place at the population level or a local adaptation has already occurred in Dictyota and other brown algae under chronic low pH.


Assuntos
Feófitas , Água do Mar , Aclimatação , Dióxido de Carbono , Concentração de Íons de Hidrogênio
3.
Mar Environ Res ; 157: 104930, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32275512

RESUMO

The distribution of macroalgal species along the north and northwest coast of the Iberian Peninsula is in a period of change, during which mostly cold-temperate species have decreased in cover and others have disappeared. On the other hand, other species have increased in abundance. These shifts could be related with the modification of environmental factors that determine species distribution caused by climate change. A standardised sampling methodology was applied at 18 sites along the north coast of Spain in 2011 and 2017. The relationship between the coverage of intertidal macroalgal species and abiotic variables (sea surface temperature, air temperature and significant wave height) was analysed in order to detect possible changes in the historical data. Results suggest a modification in the communities in the inner part of the Bay of Biscay, mostly related to an increase in water and air temperature. Each seaweed group (warm-temperate, cold-temperate, opportunistic and exotic species) showed a different pattern of modification. Coralline algae, Bifurcaria bifurcata and Cystoseira baccata have increased, which may be related to the warming trend. The exotic species Asparagopsis armata has also increased, particularly in the Lower Rias. On the other hand, there was a drastic decrease of the cold-temperate species Himanthalia elongata. Data obtained support the relationship of macroalgae species communities and environment in the context of climate change in this particular area.


Assuntos
Mudança Climática , Feófitas/classificação , Rodófitas/classificação , Alga Marinha/classificação , Espanha
4.
Phytomedicine ; 69: 153201, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32276177

RESUMO

BACKGROUND: Marine algae are rich in some unique biologically active secondary metabolites having diverse pharmacological benefits. Of these, sterols comprise a group of functional lipid compounds that have attracted much attention to natural product scientists. PURPOSE: This review was aimed to update information on the health effects of algae-derived phytosterols and their molecular interactions in various aspects of human health and diseases and to address some future perspectives that may open up a new dimension of pharmacological potentials of algal sterols. METHODS: A literature-based search was carried out to retrieve published research information on the potential health effects of algal phytosterols with their pharmacological mechanisms from accessible online databases, such as Pubmed, Google Scholar, Web of Science, and Scopus, using the key search terms of 'marine algae sterol' and 'health potentials such as antioxidant or anti-inflammatory or anti-Alzheimer's or anti-obesity or cholesterol homeostasis or hepatoprotective, antiproliferative, etc.' RESULTS: Phytosterols of marine algae, particularly fucosterol, have been investigated for a plethora of health benefits, including anti-diabetes, anti-obesity, anti-Alzheimer's, antiaging, anticancer, and hepatoprotection, among many others, which are attributed to their antioxidant, anti-inflammatory, immunomodulatory and cholesterol-lowering properties, indicating their potentiality as therapeutic leads. These sterols interact with enzymes and various other proteins that are actively participating in different cellular pathways, including antioxidant defense system, apoptosis and cell survival, metabolism, and homeostasis. CONCLUSION: In this review, we briefly overview the chemistry, pharmacokinetics, and distribution of algal sterols, and provide critical insights into their potential health effects and the underlying pharmacological mechanisms, beyond the well-known cholesterol-lowering paradigm.


Assuntos
Fitosteróis/química , Fitosteróis/farmacologia , Alga Marinha/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Organismos Aquáticos , Colesterol/metabolismo , Humanos , Feófitas/química , Fitosteróis/análise , Fitosteróis/farmacocinética , Rodófitas/química , Estigmasterol/análogos & derivados , Estigmasterol/farmacologia , Distribuição Tecidual
5.
Mar Drugs ; 18(2)2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32046368

RESUMO

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had the highest levels of sugars, acids and sulphation among molecular weight fractions. There was a dose-dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in the sub-G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress-induced apoptosis-like cell death for F. vesiculosus fucoidan and features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment.


Assuntos
Linhagem Celular Tumoral/efeitos dos fármacos , Polissacarídeos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Fucus/química , Humanos , Mitocôndrias/efeitos dos fármacos , Peso Molecular , Osteossarcoma , Feófitas/química , Sargassum/química
6.
J Plant Res ; 133(3): 283-290, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32095969

RESUMO

One of the most transformative events in the history of life on earth was the transition of plants from water to land approximately 470 million years ago. Within the Charophyte green algae, the closest living relatives of land plants, body plans have evolved from those that comprise simple unicells to those that are morphologically complex, large and multicellular. The Charophytes developed these broad ranging body plans by exploiting a range of one-dimensional and two-dimensional growth strategies to produce filaments, mats and branches. When plants were confronted with harsh conditions on land, they were required to make significant changes to the way they shaped their body plans. One of the fundamental developmental transitions that occurred was the evolution of three-dimensional growth and the acquisition of apical cells with three or more cutting faces. Plants subsequently developed a range of morphological adaptations (e.g. vasculature, roots, flowers, seeds) that enabled them to colonise progressively drier environments. 3D apical growth also evolved convergently in the brown algae, completely independently of the green lineage. This review summarises the evolving developmental complexities observed in the early divergent Charophytes all the way through to the earliest conquerors of land, and investigates 3D apical growth in the brown algae.


Assuntos
Evolução Biológica , Clorófitas/crescimento & desenvolvimento , Embriófitas/crescimento & desenvolvimento , Filogenia , Clorófitas/classificação , Embriófitas/classificação , Flores , Feófitas/classificação , Feófitas/crescimento & desenvolvimento , Raízes de Plantas
7.
Mar Genomics ; 52: 100740, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31937506

RESUMO

Brown algae are multicellular photosynthetic stramenopiles that colonize marine rocky shores worldwide. Ectocarpus sp. Ec32 has been established as a genomic model for brown algae. Here we present the genome and metabolic network of the closely related species, Ectocarpus subulatus Kützing, which is characterized by high abiotic stress tolerance. Since their separation, both strains show new traces of viral sequences and the activity of large retrotransposons, which may also be related to the expansion of a family of chlorophyll-binding proteins. Further features suspected to contribute to stress tolerance include an expanded family of heat shock proteins, the reduction of genes involved in the production of halogenated defence compounds, and the presence of fewer cell wall polysaccharide-modifying enzymes. Overall, E. subulatus has mainly lost members of gene families down-regulated in low salinities, and conserved those that were up-regulated in the same condition. However, 96% of genes that differed between the two examined Ectocarpus species, as well as all genes under positive selection, were found to encode proteins of unknown function. This underlines the uniqueness of brown algal stress tolerance mechanisms as well as the significance of establishing E. subulatus as a comparative model for future functional studies.


Assuntos
Genoma/genética , Feófitas/genética , Estresse Fisiológico/genética , Proteínas de Algas/genética , Redes e Vias Metabólicas/genética , Família Multigênica/genética , Vitória
8.
Ecotoxicol Environ Saf ; 190: 110089, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31896472

RESUMO

The use of algae to adsorb heavy metals is an efficient and environmentally friendly treatment for contaminated water and has attracted widespread research attention. In this study, a meta-analysis of the heavy metal adsorption capacity of algae from five different phyla and the factors influencing these capacities was conducted. Phaeophyta was found to have a high heavy metal adsorption capacity, whereas Bacillariophyta had a relatively low adsorption capacity; Chlorophyta, Rhodophyta, and Cyanophyta had moderate adsorption capacities. Non-living algae were more effective in practical applications than living algae were. Algal biomass had a relatively high adsorption efficiency of 1-10 g/L, which did not increase significantly when algal concentration increased. The algal adsorption efficiency for initial heavy metal concentrations of 10-100 mg/L was higher than for concentrations of greater than 100 mg/L. The results further show that algal adsorption of heavy metals reached a maximum capacity of 80-90% within 20 min. Heavy metal adsorption by algae was not temperature-dependent, and it was more effective in moderately to weakly acidic environments (pH = 4-7.5). Considering these aspects for practical applications, algae from some phyla can effectively be used for heavy metal biosorption in contaminated water.


Assuntos
Clorófitas/metabolismo , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Feófitas , Rodófitas , Temperatura
9.
Int J Syst Evol Microbiol ; 70(3): 2096-2102, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31999242

RESUMO

A Gram-stain-negative, facultatively anaerobic, flagellated and rod-shaped bacterium, designated strain SM1901T, was isolated from a brown algal sample collected from Kings Bay, Svalbard, Arctic. Strain SM1901T grew at -4‒30 °C and with 0-7.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed DNA and Tween 80. Results of phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SM1901T was affiliated with the genus Shewanella, showing the highest sequence similarity to the type strain of Shewanella litoralis (97.5%), followed by those of Shewanella vesiculosa, Shewanella livingstonensis and Shewanella saliphila (97.3 % for all three). The major cellular fatty acids were summed feature 3 (C16 : 1 ω7с and/or C16 : 1 ω6с), C16 : 0, C18 : 0, iso-C15 : 0 and C17 : 1 ω8с and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The respiratory quinones were ubiquinones Q-7, Q-8, menaquinones MK-7(H) and MK-8. The genome of strain SM1901T was 4648537 nucleotides long and encoded a variety of cold adaptation related genes, providing clues for better understanding the ecological adaptation mechanisms of polar bacteria. The genomic DNA G+C content of strain SM1901T was 40.5 mol%. Based on the polyphasic evidence presented in this paper, strain SM1901T was considered to represent a novel species, constituting a novel psychrotolerant lineage out of the known SF clade encompassed by polar Shewanella species, within the genus Shewanella, for which the name Shewanella polaris sp. nov. is proposed. The type strain is SM1901T (=KCTC 72047T=MCCC 1K03585T).


Assuntos
Feófitas/microbiologia , Shewanella/classificação , Regiões Árticas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Shewanella/isolamento & purificação , Svalbard , Ubiquinona/química , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
Physiol Plant ; 168(1): 5-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31267544

RESUMO

The Arctic region is currently facing substantial environmental changes due to global warming. Melting glaciers cause reduced salinity environments in coastal Arctic habitats, which may be stressful for kelp beds. To investigate the responses of the kelp Saccharina latissima to the warming Arctic, we studied the transcriptomic changes of S. latissima from Kongsfjorden (Svalbard, Norway) over a 24-hour exposure to two salinities (Absolute Salinity [SA ] 20 and 30) after a 7-day pre-acclimation at three temperatures (0, 8 and 15°C). In addition, corresponding physiological data were assessed during an 11-days salinity/temperature experiment. Growth and maximal quantum yield for photosystem II fluorescence were positively affected by increased temperature during acclimation, whereas hyposalinity caused negative effects at the last day of treatment. In contrast, hyposalinity induced marked changes on the transcriptomic level. Compared to the control (8°C - SA 30), the 8°C - SA 20 exhibited the highest number of differentially expressed genes (DEGs), followed by the 0°C - SA 20. Comparisons indicate that S. latissima tends to convert its energy from primary metabolism (e.g. photosynthesis) to antioxidant activity under hyposaline stress. The increase in physiological performance at 15°C shows that S. latissima in the Arctic region can adjust and might even benefit from increased temperatures. However, in Arctic fjord environments its performance might become impaired by decreased salinity as a result of ice melting.


Assuntos
Aclimatação , Mudança Climática , Kelp/fisiologia , Feófitas/fisiologia , Transcriptoma , Regiões Árticas , Fotossíntese , Complexo de Proteína do Fotossistema II/fisiologia , Salinidade , Estresse Fisiológico , Svalbard
11.
J Chromatogr A ; 1609: 460459, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31445800

RESUMO

Sulfate (SO4-sug) and sulfonate (SO3-sug) arsenosugar standard solutions were obtained using preparative liquid chromatography. Several commercial algae samples were characterized (total contents and speciation) to select the most appropriate in relation to their arsenosugar contents. Water extracts from the selected sample (Fucus vesiculosus) were fractionated using a Hamilton PRP-X100 preparative column, and the presence of arsenic species in the isolated fractions was ascertained by IC-ICP-MS. Two of the fractions successfully presented only one arsenic species corresponding to sulfate and sulfonate arsenosugars at suitable concentrations. To unequivocally confirm the presence of both compounds, high-resolution mass spectrometry (ESI-TOF/MS) was used and the exact mass determined with errors lower than 0.5 ppm. The standard solutions obtained were successfully used to identify and quantify SO4-sug and SO3-sug in several edible algae samples purchased in local market. Total arsenic content for analyzed samples ranged from 34 to 57 mg kg-1, concentration values found for SO3-sug ranged from 5 to 36 mg As kg-1 and SO4-sug was only found in fucus with a concentration of 9.3 mg As kg-1.


Assuntos
Arseniatos/química , Arseniatos/isolamento & purificação , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Feófitas/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Cromatografia Líquida , Espectrometria de Massas , Água/química
12.
Int J Syst Evol Microbiol ; 70(3): 1496-1502, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31751196

RESUMO

A Gram-stain-negative, aerobic, non-motile and rod-shaped marine bacterium, CW2-9T, was isolated from algae collected from Fujian Province in PR China. 16S rRNA gene sequence analysis showed that this strain was affiliated with the genus Tamlana in the family Flavobacteriaceae of the class Flavobacteriia and was very similar to the type strain Tamlana sedimentorum MCCC 1A10799T (96.3 % sequence similarity). The whole genome of strain CW2-9T comprised 3 997 513 bp with a G+C content of 34.3 mol%. The average nucleotide identity value between strain CW2-9T and T. sedimentorum MCCC 1A10799T was 73.8 %. Growth was observed from 15 to 40 °C (optimum, 30 °C), at pH from pH 5.0 to 10.0 (pH 8.0) and in the presence of 0-4 % (w/v) NaCl (0-1 %). The major fatty acids (>10 % of the total) were iso-C15 : 0, iso G-C15 : 1, iso-C17 : 0 3-OH and anteiso-C15 : 0. The predominant menaquinone was MK-6. The combined phylogenetic, physiological and chemotaxonomic data indicate that strain CW2-9T represents a novel species in the genus Tamlana, for which the name Tamlana fucoidanivorans sp. nov. is proposed. The type strain is CW2-9T (=CICC 24749T=KCTC 72389T).


Assuntos
Flavobacteriaceae/classificação , Feófitas/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
Food Chem Toxicol ; 136: 110963, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31715308

RESUMO

Excessive exposure to ultraviolet (UV) irradiation from the sun is the primary environmental factor that causes aging of the skin. Most skin diseases caused by UV are attributed to UVB (280-320 nm). The purpose of this study is to investigate the protective effect of diphlorethohydroxycarmalol (DPHC), isolated from the marine brown alga, Ishige okamurae, against UVB-induced photodamage using both in vitro and in vivo models. Results indicate that DPHC remarkably inhibited commercial collagenase and elastase activities. It also reduced intracellular levels of ROS, improved cell viability and collagen content in UVB-irradiated human dermal fibroblasts (HDF cells). In addition, DPHC significantly inhibited activities of intracellular collagenase and elastase and reduced the expression of matrix metalloproteinases (MMPs) and pro-inflammatory cytokines. These events occurred through regulation of nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), and mitogen-activated protein kinases (MAPKs) signaling pathways in UVB-irradiated HDF cells. Furthermore, DPHC also protected against in vivo photodamage by decreasing cell death through reducing lipid peroxidation and inflammatory response via decreasing ROS levels in UVB-irradiated zebrafish. In conclusion, DPHC has strong in vitro and in vivo photoprotective effects and has the potential to be used as an ingredient in pharmaceutical and cosmeceutical industries.


Assuntos
Fibroblastos/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Feófitas/química , Protetores contra Radiação/uso terapêutico , Envelhecimento da Pele/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Colágeno/metabolismo , Colagenases/metabolismo , Fibroblastos/efeitos da radiação , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinases da Matriz/metabolismo , Elastase Pancreática/metabolismo , Protetores contra Radiação/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Envelhecimento da Pele/efeitos da radiação , Raios Ultravioleta , Peixe-Zebra
14.
J Chromatogr A ; 1612: 460658, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703890

RESUMO

Fucoidans represent an intriguing class of fucose-containing sulfated polysaccharides. The biological activities of these polysaccharides are related to their compositional and structural parameters, whereby their degree of sulfation, as well as molecular weight (MW) distribution and chain conformation play important roles. Modern NMR and mass spectrometry techniques allow elucidating details of the glycan structure, but not the structure of the whole molecules in their native state. Accordingly, the knowledge about the latter of the fucoidans is currently still limited. Contrary to traditional MW determination by SEC with column calibration, SEC with triple detection provides not only the absolute Mw, but can also give information on additional molecule characteristics. In the present study, we used this method to compare six fucoidans extracted from Fucus vesiculosus (FV), F. serratus (FS), F. evanescens (FE), Dictyosiphon foeniculaceus (DF), Laminaria digitata (LD), and Saccharina latissima (SL) concerning their molar mass (Mw, Mn, Mp, dispersity) and size (rms radius, Rh) characteristics and distribution as well as their chain conformation in solution. The tested fucoidans displayed considerable structural diversity including large differences in their MW profiles and showed to be heterogeneously composed. Fuc-FV and Fuc-SL showed the broadest MW distributions, those from Fuc-FE and Fuc-DF the narrowest ones. Most of the fucoidan fractions (except for Fuc-DF) turned out to exist as expanded flexible chains in PBS solution. The conformation data suggest branched structures with partly long side chains. The knowledge obtained by this study is useful for further fractionation and structural characterization as well as the interpretation of the bioactivity differences between the various fucoidans.


Assuntos
Feófitas/química , Polissacarídeos/química , Configuração de Carboidratos , Cromatografia em Gel , Fucus/química , Peso Molecular
15.
Sci Total Environ ; 704: 135408, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31836226

RESUMO

In 2015, the exotic seaweed Rugulopteryx okamurae was detected for the first time on the south side of the Strait of Gibraltar, in Ceuta (northern Africa). This highly sensitive area is ideal for monitoring local environmental impacts arising from global warming, as well as the intrusion of alien species. Within one year, R. okamurae became an invasive species with an overflowing competitive capacity and growth. In 2015, more than 5000 tons of upstream biomass was extracted from beaches in Ceuta, and it has since spread irrepressibly on rocky illuminated bottoms of the subtidal zone to a maximum observed depth of 40 m. The highest coverage (80-90%) of R. okamurae in Ceuta was observed between 10 and 20 m depth in illuminated habitats, where it was having a severe impact on local benthic communities which were displaced. Between 5 and 30 m depth, coverage of R. okamurae exceeded 70% over a wide variety of substrate types. A submarine sentinel sessile bioindicators permanent quadrats (SBPQ) station installed in 2013 on poorly lit, vertical, and shady substrate in the El Estrecho Natural Park, on the north side of the Strait of Gibraltar (Tarifa), detected the presence of R. okamurae in July 2016 and recorded the subsequent increase in coverage. These findings reveal the useful role of this type of monitoring SBPQ sentinel station for the detection of impacts and exotic species in marine protected areas, and for the monitoring of global warming based on indicator species. We conclude that the catastrophic bloom of R. okamurae exhibited an initial geographical expansion (2015-2017) to the northern coastal area of the Strait of Gibraltar (Tarifa-Gibraltar) and subsequent extension in the south of the Iberian Peninsula, towards the Atlantic coast (2018) and the Mediterranean coast (2019). This bloom could have been associated with the temperature peak in July 2015 and was thus possibly linked to global warming.


Assuntos
Monitoramento Ambiental , Espécies Introduzidas , Feófitas , Ecossistema , Gibraltar
16.
Environ Pollut ; 258: 113682, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31812529

RESUMO

The active use of solid fossil fuels (coal) in the production of heat and electricity has led to significant pollution, climate change, environmental degradation, and an increase in morbidity and mortality. Many countries (in particular, European ones, China, Japan, the USA, Canada, etc.) have launched programs for using plant and agricultural raw materials to produce heat and electricity by burning them instead of or together with traditional fuels. It is a promising solution to produce slurry fuels, based on a mixture of coal processing, oil refining and agricultural waste. This paper presents the results of experimental research into the formation and assessment of the most hazardous emissions (sulfur and nitrogen oxides) from the combustion of promising coal slurry fuels with straw, sunflower and algae additives, i.e. the most common agricultural waste. A comparative analysis has been carried out to identify the differences in the concentrations of sulfur and nitrogen oxides from the combustion of typical coal, coal processing waste, as well as fuel slurries with and without plant additives. It has been shown that the concentration of sulfur and nitrogen oxides can be reduced by 62-87% and 12-57%, respectively, when using small masses of plant additives (no more than 10 wt%) and maintaining high combustion heat of the slurry fuel. However, the use of algae and straw in the slurry composition can increase the HCl emissions, which requires extra measures to fight corrosion. A generalizing criterion of slurry fuel vs. coal efficiency has been formulated to illustrate significant benefits of adding plant solid waste to coal-water slurries containing petrochemicals. Straw and sunflower waste (10 wt%) were found to be the best additives to reduce the air pollutant emissions.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Carvão Mineral , Óxidos de Nitrogênio/análise , Enxofre/análise , Canadá , China , Helianthus , Japão , Feófitas , Caules de Planta , Água
17.
Genome Biol Evol ; 12(1): 3647-3655, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841132

RESUMO

Brown algae are important primary producers and ecosystem engineers in the ocean, and Ectocarpus has been established as a laboratory model for this lineage. Like most multicellular organisms, Ectocarpus is associated with a community of microorganisms, a partnership frequently referred to as holobiont due to the tight interconnections between the components. Although genomic resources for the algal host are well established, its associated microbiome is poorly characterized from a genomic point of view, limiting the possibilities of using these types of data to study host-microbe interactions. To address this gap in knowledge, we present the annotated draft genome sequences of seventy-two cultivable Ectocarpus-associated bacteria. A screening of gene clusters related to the production of secondary metabolites revealed terpene, bacteriocin, NRPS, PKS-t3, siderophore, PKS-t1, and homoserine lactone clusters to be abundant among the sequenced genomes. These compounds may be used by the bacteria to communicate with the host and other microbes. Moreover, detoxification and provision of vitamin B pathways have been observed in most sequenced genomes, highlighting potential contributions of the bacterial metabolism toward host fitness and survival. The genomes sequenced in this study form a valuable resource for comparative genomic analyses and evolutionary surveys of alga-associated bacteria. They help establish Ectocarpus as a model for brown algal holobionts and will enable the research community to produce testable hypotheses about the molecular interactions within this complex system.


Assuntos
Genoma Bacteriano , Feófitas/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Filogenia , Metabolismo Secundário/genética , Simbiose , Vitaminas/biossíntese
18.
Mater Sci Eng C Mater Biol Appl ; 107: 110352, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761165

RESUMO

In this study, we fabricated polyvinyl alcohol hydrogels containing diphlorethohydroxycarmalol (DPHC) from Ishige okamurae for its anti-bacterial effect in wound-dressing applications. First, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DPHC against Staphylococcus aureus and Pseudomonas aeruginosa were investigated, and these were found to be about 128 µg/mL and 512 µg/mL, respectively. Polyvinyl alcohol hydrogels loaded with different concentrations of DPHC were then produced for the dressing of wounds to assist in the healing process and to provide an antibacterial effect. To investigate the characteristics of the proposed PVA/DPHC hydrogels, we conducted SEM analysis, rheological analysis, thermogravimetric analysis, water swelling analysis, drug release testing, and gel fraction assessment. The antibacterial activity of the PVA/DPHC hydrogels was also tested against the gram-positive bacterium S. aureus and the gram-negative bacterium P. aeruginosa using ASTM E2149 tests. The biocompatibility of the PVA/DPHC hydrogels was assessed using in vitro indirect and direct contact tests and in vivo tests on ICR mice. The PVA/DPHC hydrogels exhibited the ability to reduce the viability of S. aureus and P. aeruginosa by about 99% in ASTM E2149 testing, while not producing any toxic effect on NHDF-Neo or HaCaT cells as shown in MTT assays and in vitro FDA fluorescence analysis. In addition, the PVA/DPHC hydrogels had a strong wound healing effect when compared to non-treated groups of ICR mice in vivo. Based on the characterization of the PVA/DPHC hydrogels in vitro and in vivo, this study suggests that the proposed hydrogel has significant potential for use in wound dressing.


Assuntos
Antibacterianos/farmacologia , Bandagens , Compostos Heterocíclicos com 3 Anéis/isolamento & purificação , Compostos Heterocíclicos com 3 Anéis/farmacologia , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Células Cultivadas , Liberação Controlada de Fármacos , Humanos , Hidrogéis/química , Masculino , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Feófitas/química , Álcool de Polivinil/química , Pseudomonas aeruginosa/efeitos dos fármacos , Reologia , Staphylococcus aureus/efeitos dos fármacos , Termogravimetria
19.
Physiol Plant ; 168(1): 3-4, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31879961

RESUMO

For plants, climate change comes with more challenging facets than just increasing temperature. While terrestrial forests are suffering from erratic rainfall, drought and wildfires, marine vegetation is under a different kind of threat. Rapidly melting polar ice caps are causing a surge of freshwater in the seas, lowering the salinity near coastlines. For marine plants adapted to grow in seawater, hyposalinity can be a serious detriment to growth. To assess the possible impact of climate change on marine flora, Li et al. (2019) explored the physiological and transcriptomic response of the kelp Saccharina latissima to increased temperature and hyposaline conditions.


Assuntos
Kelp , Feófitas , Alga Marinha , Mudança Climática , Oceanos e Mares , Água do Mar , Transcriptoma
20.
Arch Microbiol ; 202(4): 815-824, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31844948

RESUMO

Kiloniella laminariae is a true marine bacterium and the first member of the family and order, the Kiloniellaceae and Kiloniellales. K. laminariae LD81T (= DSM 19542T) was isolated from the marine macroalga Saccharina latissima and is a mesophilic, typical marine chemoheterotrophic aerobic bacterium with antifungal activity. Phylogenetic analysis of 16S rRNA gene sequence revealed the similarity of K. laminariae LD81T not only with three validly described species of the genus Kiloniella, but also with undescribed isolates and clone sequences from marine samples in the range of 93.6-96.7%. We report on the analysis of the draft genome of this alphaproteobacterium and describe some selected features. The 4.4 Mb genome has a G + C content of 51.4%, contains 4213 coding sequences including 51 RNA genes as well as 4162 protein-coding genes, and is a part of the Genomic Encyclopaedia of Bacteria and Archaea (GEBA) project. The genome provides insights into a number of metabolic properties, such as carbon and sulfur metabolism, and indicates the potential for denitrification and the biosynthesis of secondary metabolites. Comparative genome analysis was performed with K. laminariae LD81T and the animal-associated species Kiloniella majae M56.1T from a spider crab, Kiloniella spongiae MEBiC09566T from a sponge as well as Kiloniella litopenai P1-1 from a white shrimp, which all inhabit quite different marine habitats. The analysis revealed that the K. laminariae LD81T contains 1397 unique genes, more than twice the amount of the other species. Unique among others is a mixed PKS/NRPS biosynthetic gene cluster with similarity to the biosynthetic gene cluster responsible for the production of syringomycin.


Assuntos
Alphaproteobacteria/genética , Organismos Aquáticos/genética , Genômica , Filogenia , Alphaproteobacteria/classificação , Animais , Organismos Aquáticos/classificação , Organismos Aquáticos/microbiologia , Proteínas de Bactérias/genética , Composição de Bases , Feófitas/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA